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https://www.ourcommons.ca/js/knockout.js

js ourcommons.ca collected 2026-09-24 08:34:03 UTC 389,290 bytes, 6,614 lines download raw bytes

vendor: 389,290 bytes, lines 1-6614
1/*!
2 * Knockout JavaScript library v3.5.1
3 * (c) The Knockout.js team - http://knockoutjs.com/
4 * License: MIT (http://www.opensource.org/licenses/mit-license.php)
5 */
6
7(function () {
8    var DEBUG = true;
9    (function (undefined) {
10        // (0, eval)('this') is a robust way of getting a reference to the global object
11        // For details, see http://stackoverflow.com/questions/14119988/return-this-0-evalthis/14120023#14120023
12        var window = this || (0, eval)('this'),
13            document = window['document'],
14            navigator = window['navigator'],
15            jQueryInstance = window["jQuery"],
16            JSON = window["JSON"];
17
18        if (!jQueryInstance && typeof jQuery !== "undefined") {
19            jQueryInstance = jQuery;
20        }
21        (function (factory) {
22            // Support three module loading scenarios
23            if (typeof define === 'function' && define['amd']) {
24                // [1] AMD anonymous module
25                define(['exports', 'require'], factory);
26            } else if (typeof exports === 'object' && typeof module === 'object') {
27                // [2] CommonJS/Node.js
28                factory(module['exports'] || exports);  // module.exports is for Node.js
29            } else {
30                // [3] No module loader (plain <script> tag) - put directly in global namespace
31                factory(window['ko'] = {});
32            }
33        }(function (koExports, amdRequire) {
34            // Internally, all KO objects are attached to koExports (even the non-exported ones whose names will be minified by the closure compiler).
35            // In the future, the following "ko" variable may be made distinct from "koExports" so that private objects are not externally reachable.
36            var ko = typeof koExports !== 'undefined' ? koExports : {};
37            // Google Closure Compiler helpers (used only to make the minified file smaller)
38            ko.exportSymbol = function (koPath, object) {
39                var tokens = koPath.split(".");
40
41                // In the future, "ko" may become distinct from "koExports" (so that non-exported objects are not reachable)
42                // At that point, "target" would be set to: (typeof koExports !== "undefined" ? koExports : ko)
43                var target = ko;
44
45                for (var i = 0; i < tokens.length - 1; i++)
46                    target = target[tokens[i]];
47                target[tokens[tokens.length - 1]] = object;
48            };
49            ko.exportProperty = function (owner, publicName, object) {
50                owner[publicName] = object;
51            };
52            ko.version = "3.5.1";
53
54            ko.exportSymbol('version', ko.version);
55            // For any options that may affect various areas of Knockout and aren't directly associated with data binding.
56            ko.options = {
57                'deferUpdates': false,
58                'useOnlyNativeEvents': false,
59                'foreachHidesDestroyed': false
60            };
61
62            //ko.exportSymbol('options', ko.options);   // 'options' isn't minified
63            ko.utils = (function () {
64                var hasOwnProperty = Object.prototype.hasOwnProperty;
65
66                function objectForEach(obj, action) {
67                    for (var prop in obj) {
68                        if (hasOwnProperty.call(obj, prop)) {
69                            action(prop, obj[prop]);
70                        }
71                    }
72                }
73
74                function extend(target, source) {
75                    if (source) {
76                        for (var prop in source) {
77                            if (hasOwnProperty.call(source, prop)) {
78                                target[prop] = source[prop];
79                            }
80                        }
81                    }
82                    return target;
83                }
84
85                function setPrototypeOf(obj, proto) {
86                    obj.__proto__ = proto;
87                    return obj;
88                }
89
90                var canSetPrototype = ({ __proto__: [] } instanceof Array);
91                var canUseSymbols = !DEBUG && typeof Symbol === 'function';
92
93                // Represent the known event types in a compact way, then at runtime transform it into a hash with event name as key (for fast lookup)
94                var knownEvents = {}, knownEventTypesByEventName = {};
95                var keyEventTypeName = (navigator && /Firefox\/2/i.test(navigator.userAgent)) ? 'KeyboardEvent' : 'UIEvents';
96                knownEvents[keyEventTypeName] = ['keyup', 'keydown', 'keypress'];
97                knownEvents['MouseEvents'] = ['click', 'dblclick', 'mousedown', 'mouseup', 'mousemove', 'mouseover', 'mouseout', 'mouseenter', 'mouseleave'];
98                objectForEach(knownEvents, function (eventType, knownEventsForType) {
99                    if (knownEventsForType.length) {
100                        for (var i = 0, j = knownEventsForType.length; i < j; i++)
101                            knownEventTypesByEventName[knownEventsForType[i]] = eventType;
102                    }
103                });
104                var eventsThatMustBeRegisteredUsingAttachEvent = { 'propertychange': true }; // Workaround for an IE9 issue - https://github.com/SteveSanderson/knockout/issues/406
105
106                // Detect IE versions for bug workarounds (uses IE conditionals, not UA string, for robustness)
107                // Note that, since IE 10 does not support conditional comments, the following logic only detects IE < 10.
108                // Currently this is by design, since IE 10+ behaves correctly when treated as a standard browser.
109                // If there is a future need to detect specific versions of IE10+, we will amend this.
110                var ieVersion = document && (function () {
111                    var version = 3, div = document.createElement('div'), iElems = div.getElementsByTagName('i');
112
113                    // Keep constructing conditional HTML blocks until we hit one that resolves to an empty fragment
114                    while (
115                        div.innerHTML = '<!--[if gt IE ' + (++version) + ']><i></i><![endif]-->',
116                        iElems[0]
117                    ) { }
118                    return version > 4 ? version : undefined;
119                }());
120                var isIe6 = ieVersion === 6,
121                    isIe7 = ieVersion === 7;
122
123                function isClickOnCheckableElement(element, eventType) {
124                    if ((ko.utils.tagNameLower(element) !== "input") || !element.type) return false;
125                    if (eventType.toLowerCase() != "click") return false;
126                    var inputType = element.type;
127                    return (inputType == "checkbox") || (inputType == "radio");
128                }
129
130                // For details on the pattern for changing node classes
131                // see: https://github.com/knockout/knockout/issues/1597
132                var cssClassNameRegex = /\S+/g;
133
134                var jQueryEventAttachName;
135
136                function toggleDomNodeCssClass(node, classNames, shouldHaveClass) {
137                    var addOrRemoveFn;
138                    if (classNames) {
139                        if (typeof node.classList === 'object') {
140                            addOrRemoveFn = node.classList[shouldHaveClass ? 'add' : 'remove'];
141                            ko.utils.arrayForEach(classNames.match(cssClassNameRegex), function (className) {
142                                addOrRemoveFn.call(node.classList, className);
143                            });
144                        } else if (typeof node.className['baseVal'] === 'string') {
145                            // SVG tag .classNames is an SVGAnimatedString instance
146                            toggleObjectClassPropertyString(node.className, 'baseVal', classNames, shouldHaveClass);
147                        } else {
148                            // node.className ought to be a string.
149                            toggleObjectClassPropertyString(node, 'className', classNames, shouldHaveClass);
150                        }
151                    }
152                }
153
154                function toggleObjectClassPropertyString(obj, prop, classNames, shouldHaveClass) {
155                    // obj/prop is either a node/'className' or a SVGAnimatedString/'baseVal'.
156                    var currentClassNames = obj[prop].match(cssClassNameRegex) || [];
157                    ko.utils.arrayForEach(classNames.match(cssClassNameRegex), function (className) {
158                        ko.utils.addOrRemoveItem(currentClassNames, className, shouldHaveClass);
159                    });
160                    obj[prop] = currentClassNames.join(" ");
161                }
162
163                return {
164                    fieldsIncludedWithJsonPost: ['authenticity_token', /^__RequestVerificationToken(_.*)?$/],
165
166                    arrayForEach: function (array, action, actionOwner) {
167                        for (var i = 0, j = array.length; i < j; i++) {
168                            action.call(actionOwner, array[i], i, array);
169                        }
170                    },
171
172                    arrayIndexOf: typeof Array.prototype.indexOf == "function"
173                        ? function (array, item) {
174                            return Array.prototype.indexOf.call(array, item);
175                        }
176                        : function (array, item) {
177                            for (var i = 0, j = array.length; i < j; i++) {
178                                if (array[i] === item)
179                                    return i;
180                            }
181                            return -1;
182                        },
183
184                    arrayFirst: function (array, predicate, predicateOwner) {
185                        for (var i = 0, j = array.length; i < j; i++) {
186                            if (predicate.call(predicateOwner, array[i], i, array))
187                                return array[i];
188                        }
189                        return undefined;
190                    },
191
192                    arrayRemoveItem: function (array, itemToRemove) {
193                        var index = ko.utils.arrayIndexOf(array, itemToRemove);
194                        if (index > 0) {
195                            array.splice(index, 1);
196                        }
197                        else if (index === 0) {
198                            array.shift();
199                        }
200                    },
201
202                    arrayGetDistinctValues: function (array) {
203                        var result = [];
204                        if (array) {
205                            ko.utils.arrayForEach(array, function (item) {
206                                if (ko.utils.arrayIndexOf(result, item) < 0)
207                                    result.push(item);
208                            });
209                        }
210                        return result;
211                    },
212
213                    arrayMap: function (array, mapping, mappingOwner) {
214                        var result = [];
215                        if (array) {
216                            for (var i = 0, j = array.length; i < j; i++)
217                                result.push(mapping.call(mappingOwner, array[i], i));
218                        }
219                        return result;
220                    },
221
222                    arrayFilter: function (array, predicate, predicateOwner) {
223                        var result = [];
224                        if (array) {
225                            for (var i = 0, j = array.length; i < j; i++)
226                                if (predicate.call(predicateOwner, array[i], i))
227                                    result.push(array[i]);
228                        }
229                        return result;
230                    },
231
232                    arrayPushAll: function (array, valuesToPush) {
233                        if (valuesToPush instanceof Array)
234                            array.push.apply(array, valuesToPush);
235                        else
236                            for (var i = 0, j = valuesToPush.length; i < j; i++)
237                                array.push(valuesToPush[i]);
238                        return array;
239                    },
240
241                    addOrRemoveItem: function (array, value, included) {
242                        var existingEntryIndex = ko.utils.arrayIndexOf(ko.utils.peekObservable(array), value);
243                        if (existingEntryIndex < 0) {
244                            if (included)
245                                array.push(value);
246                        } else {
247                            if (!included)
248                                array.splice(existingEntryIndex, 1);
249                        }
250                    },
251
252                    canSetPrototype: canSetPrototype,
253
254                    extend: extend,
255
256                    setPrototypeOf: setPrototypeOf,
257
258                    setPrototypeOfOrExtend: canSetPrototype ? setPrototypeOf : extend,
259
260                    objectForEach: objectForEach,
261
262                    objectMap: function (source, mapping, mappingOwner) {
263                        if (!source)
264                            return source;
265                        var target = {};
266                        for (var prop in source) {
267                            if (hasOwnProperty.call(source, prop)) {
268                                target[prop] = mapping.call(mappingOwner, source[prop], prop, source);
269                            }
270                        }
271                        return target;
272                    },
273
274                    emptyDomNode: function (domNode) {
275                        while (domNode.firstChild) {
276                            ko.removeNode(domNode.firstChild);
277                        }
278                    },
279
280                    moveCleanedNodesToContainerElement: function (nodes) {
281                        // Ensure it's a real array, as we're about to reparent the nodes and
282                        // we don't want the underlying collection to change while we're doing that.
283                        var nodesArray = ko.utils.makeArray(nodes);
284                        var templateDocument = (nodesArray[0] && nodesArray[0].ownerDocument) || document;
285
286                        var container = templateDocument.createElement('div');
287                        for (var i = 0, j = nodesArray.length; i < j; i++) {
288                            container.appendChild(ko.cleanNode(nodesArray[i]));
289                        }
290                        return container;
291                    },
292
293                    cloneNodes: function (nodesArray, shouldCleanNodes) {
294                        for (var i = 0, j = nodesArray.length, newNodesArray = []; i < j; i++) {
295                            var clonedNode = nodesArray[i].cloneNode(true);
296                            newNodesArray.push(shouldCleanNodes ? ko.cleanNode(clonedNode) : clonedNode);
297                        }
298                        return newNodesArray;
299                    },
300
301                    setDomNodeChildren: function (domNode, childNodes) {
302                        ko.utils.emptyDomNode(domNode);
303                        if (childNodes) {
304                            for (var i = 0, j = childNodes.length; i < j; i++)
305                                domNode.appendChild(childNodes[i]);
306                        }
307                    },
308
309                    replaceDomNodes: function (nodeToReplaceOrNodeArray, newNodesArray) {
310                        var nodesToReplaceArray = nodeToReplaceOrNodeArray.nodeType ? [nodeToReplaceOrNodeArray] : nodeToReplaceOrNodeArray;
311                        if (nodesToReplaceArray.length > 0) {
312                            var insertionPoint = nodesToReplaceArray[0];
313                            var parent = insertionPoint.parentNode;
314                            for (var i = 0, j = newNodesArray.length; i < j; i++)
315                                parent.insertBefore(newNodesArray[i], insertionPoint);
316                            for (var i = 0, j = nodesToReplaceArray.length; i < j; i++) {
317                                ko.removeNode(nodesToReplaceArray[i]);
318                            }
319                        }
320                    },
321
322                    fixUpContinuousNodeArray: function (continuousNodeArray, parentNode) {
323                        // Before acting on a set of nodes that were previously outputted by a template function, we have to reconcile
324                        // them against what is in the DOM right now. It may be that some of the nodes have already been removed, or that
325                        // new nodes might have been inserted in the middle, for example by a binding. Also, there may previously have been
326                        // leading comment nodes (created by rewritten string-based templates) that have since been removed during binding.
327                        // So, this function translates the old "map" output array into its best guess of the set of current DOM nodes.
328                        //
329                        // Rules:
330                        //   [A] Any leading nodes that have been removed should be ignored
331                        //       These most likely correspond to memoization nodes that were already removed during binding
332                        //       See https://github.com/knockout/knockout/pull/440
333                        //   [B] Any trailing nodes that have been remove should be ignored
334                        //       This prevents the code here from adding unrelated nodes to the array while processing rule [C]
335                        //       See https://github.com/knockout/knockout/pull/1903
336                        //   [C] We want to output a continuous series of nodes. So, ignore any nodes that have already been removed,
337                        //       and include any nodes that have been inserted among the previous collection
338
339                        if (continuousNodeArray.length) {
340                            // The parent node can be a virtual element; so get the real parent node
341                            parentNode = (parentNode.nodeType === 8 && parentNode.parentNode) || parentNode;
342
343                            // Rule [A]
344                            while (continuousNodeArray.length && continuousNodeArray[0].parentNode !== parentNode)
345                                continuousNodeArray.splice(0, 1);
346
347                            // Rule [B]
348                            while (continuousNodeArray.length > 1 && continuousNodeArray[continuousNodeArray.length - 1].parentNode !== parentNode)
349                                continuousNodeArray.length--;
350
351                            // Rule [C]
352                            if (continuousNodeArray.length > 1) {
353                                var current = continuousNodeArray[0], last = continuousNodeArray[continuousNodeArray.length - 1];
354                                // Replace with the actual new continuous node set
355                                continuousNodeArray.length = 0;
356                                while (current !== last) {
357                                    continuousNodeArray.push(current);
358                                    current = current.nextSibling;
359                                }
360                                continuousNodeArray.push(last);
361                            }
362                        }
363                        return continuousNodeArray;
364                    },
365
366                    setOptionNodeSelectionState: function (optionNode, isSelected) {
367                        // IE6 sometimes throws "unknown error" if you try to write to .selected directly, whereas Firefox struggles with setAttribute. Pick one based on browser.
368                        if (ieVersion < 7)
369                            optionNode.setAttribute("selected", isSelected);
370                        else
371                            optionNode.selected = isSelected;
372                    },
373
374                    stringTrim: function (string) {
375                        return string === null || string === undefined ? '' :
376                            string.trim ?
377                                string.trim() :
378                                string.toString().replace(/^[\s\xa0]+|[\s\xa0]+$/g, '');
379                    },
380
381                    stringStartsWith: function (string, startsWith) {
382                        string = string || "";
383                        if (startsWith.length > string.length)
384                            return false;
385                        return string.substring(0, startsWith.length) === startsWith;
386                    },
387
388                    domNodeIsContainedBy: function (node, containedByNode) {
389                        if (node === containedByNode)
390                            return true;
391                        if (node.nodeType === 11)
392                            return false; // Fixes issue #1162 - can't use node.contains for document fragments on IE8
393                        if (containedByNode.contains)
394                            return containedByNode.contains(node.nodeType !== 1 ? node.parentNode : node);
395                        if (containedByNode.compareDocumentPosition)
396                            return (containedByNode.compareDocumentPosition(node) & 16) == 16;
397                        while (node && node != containedByNode) {
398                            node = node.parentNode;
399                        }
400                        return !!node;
401                    },
402
403                    domNodeIsAttachedToDocument: function (node) {
404                        return ko.utils.domNodeIsContainedBy(node, node.ownerDocument.documentElement);
405                    },
406
407                    anyDomNodeIsAttachedToDocument: function (nodes) {
408                        return !!ko.utils.arrayFirst(nodes, ko.utils.domNodeIsAttachedToDocument);
409                    },
410
411                    tagNameLower: function (element) {
412                        // For HTML elements, tagName will always be upper case; for XHTML elements, it'll be lower case.
413                        // Possible future optimization: If we know it's an element from an XHTML document (not HTML),
414                        // we don't need to do the .toLowerCase() as it will always be lower case anyway.
415                        return element && element.tagName && element.tagName.toLowerCase();
416                    },
417
418                    catchFunctionErrors: function (delegate) {
419                        return ko['onError'] ? function () {
420                            try {
421                                return delegate.apply(this, arguments);
422                            } catch (e) {
423                                ko['onError'] && ko['onError'](e);
424                                throw e;
425                            }
426                        } : delegate;
427                    },
428
429                    setTimeout: function (handler, timeout) {
430                        return setTimeout(ko.utils.catchFunctionErrors(handler), timeout);
431                    },
432
433                    deferError: function (error) {
434                        setTimeout(function () {
435                            ko['onError'] && ko['onError'](error);
436                            throw error;
437                        }, 0);
438                    },
439
440                    registerEventHandler: function (element, eventType, handler) {
441                        var wrappedHandler = ko.utils.catchFunctionErrors(handler);
442
443                        var mustUseAttachEvent = eventsThatMustBeRegisteredUsingAttachEvent[eventType];
444                        if (!ko.options['useOnlyNativeEvents'] && !mustUseAttachEvent && jQueryInstance) {
445                            if (!jQueryEventAttachName) {
446                                jQueryEventAttachName = (typeof jQueryInstance(element)['on'] == 'function') ? 'on' : 'bind';
447                            }
448                            jQueryInstance(element)[jQueryEventAttachName](eventType, wrappedHandler);
449                        } else if (!mustUseAttachEvent && typeof element.addEventListener == "function")
450                            element.addEventListener(eventType, wrappedHandler, false);
451                        else if (typeof element.attachEvent != "undefined") {
452                            var attachEventHandler = function (event) { wrappedHandler.call(element, event); },
453                                attachEventName = "on" + eventType;
454                            element.attachEvent(attachEventName, attachEventHandler);
455
456                            // IE does not dispose attachEvent handlers automatically (unlike with addEventListener)
457                            // so to avoid leaks, we have to remove them manually. See bug #856
458                            ko.utils.domNodeDisposal.addDisposeCallback(element, function () {
459                                element.detachEvent(attachEventName, attachEventHandler);
460                            });
461                        } else
462                            throw new Error("Browser doesn't support addEventListener or attachEvent");
463                    },
464
465                    triggerEvent: function (element, eventType) {
466                        if (!(element && element.nodeType))
467                            throw new Error("element must be a DOM node when calling triggerEvent");
468
469                        // For click events on checkboxes and radio buttons, jQuery toggles the element checked state *after* the
470                        // event handler runs instead of *before*. (This was fixed in 1.9 for checkboxes but not for radio buttons.)
471                        // IE doesn't change the checked state when you trigger the click event using "fireEvent".
472                        // In both cases, we'll use the click method instead.
473                        var useClickWorkaround = isClickOnCheckableElement(element, eventType);
474
475                        if (!ko.options['useOnlyNativeEvents'] && jQueryInstance && !useClickWorkaround) {
476                            jQueryInstance(element)['trigger'](eventType);
477                        } else if (typeof document.createEvent == "function") {
478                            if (typeof element.dispatchEvent == "function") {
479                                var eventCategory = knownEventTypesByEventName[eventType] || "HTMLEvents";
480                                var event = document.createEvent(eventCategory);
481                                event.initEvent(eventType, true, true, window, 0, 0, 0, 0, 0, false, false, false, false, 0, element);
482                                element.dispatchEvent(event);
483                            }
484                            else
485                                throw new Error("The supplied element doesn't support dispatchEvent");
486                        } else if (useClickWorkaround && element.click) {
487                            element.click();
488                        } else if (typeof element.fireEvent != "undefined") {
489                            element.fireEvent("on" + eventType);
490                        } else {
491                            throw new Error("Browser doesn't support triggering events");
492                        }
493                    },
494
495                    unwrapObservable: function (value) {
496                        return ko.isObservable(value) ? value() : value;
497                    },
498
499                    peekObservable: function (value) {
500                        return ko.isObservable(value) ? value.peek() : value;
501                    },
502
503                    toggleDomNodeCssClass: toggleDomNodeCssClass,
504
505                    setTextContent: function (element, textContent) {
506                        var value = ko.utils.unwrapObservable(textContent);
507                        if ((value === null) || (value === undefined))
508                            value = "";
509
510                        // We need there to be exactly one child: a text node.
511                        // If there are no children, more than one, or if it's not a text node,
512                        // we'll clear everything and create a single text node.
513                        var innerTextNode = ko.virtualElements.firstChild(element);
514                        if (!innerTextNode || innerTextNode.nodeType != 3 || ko.virtualElements.nextSibling(innerTextNode)) {
515                            ko.virtualElements.setDomNodeChildren(element, [element.ownerDocument.createTextNode(value)]);
516                        } else {
517                            innerTextNode.data = value;
518                        }
519
520                        ko.utils.forceRefresh(element);
521                    },
522
523                    setElementName: function (element, name) {
524                        element.name = name;
525
526                        // Workaround IE 6/7 issue
527                        // - https://github.com/SteveSanderson/knockout/issues/197
528                        // - http://www.matts411.com/post/setting_the_name_attribute_in_ie_dom/
529                        if (ieVersion <= 7) {
530                            try {
531                                var escapedName = element.name.replace(/[&<>'"]/g, function (r) { return "&#" + r.charCodeAt(0) + ";"; });
532                                element.mergeAttributes(document.createElement("<input name='" + escapedName + "'/>"), false);
533                            }
534                            catch (e) { } // For IE9 with doc mode "IE9 Standards" and browser mode "IE9 Compatibility View"
535                        }
536                    },
537
538                    forceRefresh: function (node) {
539                        // Workaround for an IE9 rendering bug - https://github.com/SteveSanderson/knockout/issues/209
540                        if (ieVersion >= 9) {
541                            // For text nodes and comment nodes (most likely virtual elements), we will have to refresh the container
542                            var elem = node.nodeType == 1 ? node : node.parentNode;
543                            if (elem.style)
544                                elem.style.zoom = elem.style.zoom;
545                        }
546                    },
547
548                    ensureSelectElementIsRenderedCorrectly: function (selectElement) {
549                        // Workaround for IE9 rendering bug - it doesn't reliably display all the text in dynamically-added select boxes unless you force it to re-render by updating the width.
550                        // (See https://github.com/SteveSanderson/knockout/issues/312, http://stackoverflow.com/questions/5908494/select-only-shows-first-char-of-selected-option)
551                        // Also fixes IE7 and IE8 bug that causes selects to be zero width if enclosed by 'if' or 'with'. (See issue #839)
552                        if (ieVersion) {
553                            var originalWidth = selectElement.style.width;
554                            selectElement.style.width = 0;
555                            selectElement.style.width = originalWidth;
556                        }
557                    },
558
559                    range: function (min, max) {
560                        min = ko.utils.unwrapObservable(min);
561                        max = ko.utils.unwrapObservable(max);
562                        var result = [];
563                        for (var i = min; i <= max; i++)
564                            result.push(i);
565                        return result;
566                    },
567
568                    makeArray: function (arrayLikeObject) {
569                        var result = [];
570                        for (var i = 0, j = arrayLikeObject.length; i < j; i++) {
571                            result.push(arrayLikeObject[i]);
572                        };
573                        return result;
574                    },
575
576                    createSymbolOrString: function (identifier) {
577                        return canUseSymbols ? Symbol(identifier) : identifier;
578                    },
579
580                    isIe6: isIe6,
581                    isIe7: isIe7,
582                    ieVersion: ieVersion,
583
584                    getFormFields: function (form, fieldName) {
585                        var fields = ko.utils.makeArray(form.getElementsByTagName("input")).concat(ko.utils.makeArray(form.getElementsByTagName("textarea")));
586                        var isMatchingField = (typeof fieldName == 'string')
587                            ? function (field) { return field.name === fieldName }
588                            : function (field) { return fieldName.test(field.name) }; // Treat fieldName as regex or object containing predicate
589                        var matches = [];
590                        for (var i = fields.length - 1; i >= 0; i--) {
591                            if (isMatchingField(fields[i]))
592                                matches.push(fields[i]);
593                        };
594                        return matches;
595                    },
596
597                    parseJson: function (jsonString) {
598                        if (typeof jsonString == "string") {
599                            jsonString = ko.utils.stringTrim(jsonString);
600                            if (jsonString) {
601                                if (JSON && JSON.parse) // Use native parsing where available
602                                    return JSON.parse(jsonString);
603                                return (new Function("return " + jsonString))(); // Fallback on less safe parsing for older browsers
604                            }
605                        }
606                        return null;
607                    },
608
609                    stringifyJson: function (data, replacer, space) {   // replacer and space are optional
610                        if (!JSON || !JSON.stringify)
611                            throw new Error("Cannot find JSON.stringify(). Some browsers (e.g., IE < 8) don't support it natively, but you can overcome this by adding a script reference to json2.js, downloadable from http://www.json.org/json2.js");
612                        return JSON.stringify(ko.utils.unwrapObservable(data), replacer, space);
613                    },
614
615                    postJson: function (urlOrForm, data, options) {
616                        options = options || {};
617                        var params = options['params'] || {};
618                        var includeFields = options['includeFields'] || this.fieldsIncludedWithJsonPost;
619                        var url = urlOrForm;
620
621                        // If we were given a form, use its 'action' URL and pick out any requested field values
622                        if ((typeof urlOrForm == 'object') && (ko.utils.tagNameLower(urlOrForm) === "form")) {
623                            var originalForm = urlOrForm;
624                            url = originalForm.action;
625                            for (var i = includeFields.length - 1; i >= 0; i--) {
626                                var fields = ko.utils.getFormFields(originalForm, includeFields[i]);
627                                for (var j = fields.length - 1; j >= 0; j--)
628                                    params[fields[j].name] = fields[j].value;
629                            }
630                        }
631
632                        data = ko.utils.unwrapObservable(data);
633                        var form = document.createElement("form");
634                        form.style.display = "none";
635                        form.action = url;
636                        form.method = "post";
637                        for (var key in data) {
638                            // Since 'data' this is a model object, we include all properties including those inherited from its prototype
639                            var input = document.createElement("input");
640                            input.type = "hidden";
641                            input.name = key;
642                            input.value = ko.utils.stringifyJson(ko.utils.unwrapObservable(data[key]));
643                            form.appendChild(input);
644                        }
645                        objectForEach(params, function (key, value) {
646                            var input = document.createElement("input");
647                            input.type = "hidden";
648                            input.name = key;
649                            input.value = value;
650                            form.appendChild(input);
651                        });
652                        document.body.appendChild(form);
653                        options['submitter'] ? options['submitter'](form) : form.submit();
654                        setTimeout(function () { form.parentNode.removeChild(form); }, 0);
655                    }
656                }
657            }());
658
659            ko.exportSymbol('utils', ko.utils);
660            ko.exportSymbol('utils.arrayForEach', ko.utils.arrayForEach);
661            ko.exportSymbol('utils.arrayFirst', ko.utils.arrayFirst);
662            ko.exportSymbol('utils.arrayFilter', ko.utils.arrayFilter);
663            ko.exportSymbol('utils.arrayGetDistinctValues', ko.utils.arrayGetDistinctValues);
664            ko.exportSymbol('utils.arrayIndexOf', ko.utils.arrayIndexOf);
665            ko.exportSymbol('utils.arrayMap', ko.utils.arrayMap);
666            ko.exportSymbol('utils.arrayPushAll', ko.utils.arrayPushAll);
667            ko.exportSymbol('utils.arrayRemoveItem', ko.utils.arrayRemoveItem);
668            ko.exportSymbol('utils.cloneNodes', ko.utils.cloneNodes);
669            ko.exportSymbol('utils.createSymbolOrString', ko.utils.createSymbolOrString);
670            ko.exportSymbol('utils.extend', ko.utils.extend);
671            ko.exportSymbol('utils.fieldsIncludedWithJsonPost', ko.utils.fieldsIncludedWithJsonPost);
672            ko.exportSymbol('utils.getFormFields', ko.utils.getFormFields);
673            ko.exportSymbol('utils.objectMap', ko.utils.objectMap);
674            ko.exportSymbol('utils.peekObservable', ko.utils.peekObservable);
675            ko.exportSymbol('utils.postJson', ko.utils.postJson);
676            ko.exportSymbol('utils.parseJson', ko.utils.parseJson);
677            ko.exportSymbol('utils.registerEventHandler', ko.utils.registerEventHandler);
678            ko.exportSymbol('utils.stringifyJson', ko.utils.stringifyJson);
679            ko.exportSymbol('utils.range', ko.utils.range);
680            ko.exportSymbol('utils.toggleDomNodeCssClass', ko.utils.toggleDomNodeCssClass);
681            ko.exportSymbol('utils.triggerEvent', ko.utils.triggerEvent);
682            ko.exportSymbol('utils.unwrapObservable', ko.utils.unwrapObservable);
683            ko.exportSymbol('utils.objectForEach', ko.utils.objectForEach);
684            ko.exportSymbol('utils.addOrRemoveItem', ko.utils.addOrRemoveItem);
685            ko.exportSymbol('utils.setTextContent', ko.utils.setTextContent);
686            ko.exportSymbol('unwrap', ko.utils.unwrapObservable); // Convenient shorthand, because this is used so commonly
687
688            if (!Function.prototype['bind']) {
689                // Function.prototype.bind is a standard part of ECMAScript 5th Edition (December 2009, http://www.ecma-international.org/publications/files/ECMA-ST/ECMA-262.pdf)
690                // In case the browser doesn't implement it natively, provide a JavaScript implementation. This implementation is based on the one in prototype.js
691                Function.prototype['bind'] = function (object) {
692                    var originalFunction = this;
693                    if (arguments.length === 1) {
694                        return function () {
695                            return originalFunction.apply(object, arguments);
696                        };
697                    } else {
698                        var partialArgs = Array.prototype.slice.call(arguments, 1);
699                        return function () {
700                            var args = partialArgs.slice(0);
701                            args.push.apply(args, arguments);
702                            return originalFunction.apply(object, args);
703                        };
704                    }
705                };
706            }
707
708            ko.utils.domData = new (function () {
709                var uniqueId = 0;
710                var dataStoreKeyExpandoPropertyName = "__ko__" + (new Date).getTime();
711                var dataStore = {};
712
713                var getDataForNode, clear;
714                if (!ko.utils.ieVersion) {
715                    // We considered using WeakMap, but it has a problem in IE 11 and Edge that prevents using
716                    // it cross-window, so instead we just store the data directly on the node.
717                    // See https://github.com/knockout/knockout/issues/2141
718                    getDataForNode = function (node, createIfNotFound) {
719                        var dataForNode = node[dataStoreKeyExpandoPropertyName];
720                        if (!dataForNode && createIfNotFound) {
721                            dataForNode = node[dataStoreKeyExpandoPropertyName] = {};
722                        }
723                        return dataForNode;
724                    };
725                    clear = function (node) {
726                        if (node[dataStoreKeyExpandoPropertyName]) {
727                            delete node[dataStoreKeyExpandoPropertyName];
728                            return true; // Exposing "did clean" flag purely so specs can infer whether things have been cleaned up as intended
729                        }
730                        return false;
731                    };
732                } else {
733                    // Old IE versions have memory issues if you store objects on the node, so we use a
734                    // separate data storage and link to it from the node using a string key.
735                    getDataForNode = function (node, createIfNotFound) {
736                        var dataStoreKey = node[dataStoreKeyExpandoPropertyName];
737                        var hasExistingDataStore = dataStoreKey && (dataStoreKey !== "null") && dataStore[dataStoreKey];
738                        if (!hasExistingDataStore) {
739                            if (!createIfNotFound)
740                                return undefined;
741                            dataStoreKey = node[dataStoreKeyExpandoPropertyName] = "ko" + uniqueId++;
742                            dataStore[dataStoreKey] = {};
743                        }
744                        return dataStore[dataStoreKey];
745                    };
746                    clear = function (node) {
747                        var dataStoreKey = node[dataStoreKeyExpandoPropertyName];
748                        if (dataStoreKey) {
749                            delete dataStore[dataStoreKey];
750                            node[dataStoreKeyExpandoPropertyName] = null;
751                            return true; // Exposing "did clean" flag purely so specs can infer whether things have been cleaned up as intended
752                        }
753                        return false;
754                    };
755                }
756
757                return {
758                    get: function (node, key) {
759                        var dataForNode = getDataForNode(node, false);
760                        return dataForNode && dataForNode[key];
761                    },
762                    set: function (node, key, value) {
763                        // Make sure we don't actually create a new domData key if we are actually deleting a value
764                        var dataForNode = getDataForNode(node, value !== undefined /* createIfNotFound */);
765                        dataForNode && (dataForNode[key] = value);
766                    },
767                    getOrSet: function (node, key, value) {
768                        var dataForNode = getDataForNode(node, true /* createIfNotFound */);
769                        return dataForNode[key] || (dataForNode[key] = value);
770                    },
771                    clear: clear,
772
773                    nextKey: function () {
774                        return (uniqueId++) + dataStoreKeyExpandoPropertyName;
775                    }
776                };
777            })();
778
779            ko.exportSymbol('utils.domData', ko.utils.domData);
780            ko.exportSymbol('utils.domData.clear', ko.utils.domData.clear); // Exporting only so specs can clear up after themselves fully
781
782            ko.utils.domNodeDisposal = new (function () {
783                var domDataKey = ko.utils.domData.nextKey();
784                var cleanableNodeTypes = { 1: true, 8: true, 9: true };       // Element, Comment, Document
785                var cleanableNodeTypesWithDescendants = { 1: true, 9: true }; // Element, Document
786
787                function getDisposeCallbacksCollection(node, createIfNotFound) {
788                    var allDisposeCallbacks = ko.utils.domData.get(node, domDataKey);
789                    if ((allDisposeCallbacks === undefined) && createIfNotFound) {
790                        allDisposeCallbacks = [];
791                        ko.utils.domData.set(node, domDataKey, allDisposeCallbacks);
792                    }
793                    return allDisposeCallbacks;
794                }
795                function destroyCallbacksCollection(node) {
796                    ko.utils.domData.set(node, domDataKey, undefined);
797                }
798
799                function cleanSingleNode(node) {
800                    // Run all the dispose callbacks
801                    var callbacks = getDisposeCallbacksCollection(node, false);
802                    if (callbacks) {
803                        callbacks = callbacks.slice(0); // Clone, as the array may be modified during iteration (typically, callbacks will remove themselves)
804                        for (var i = 0; i < callbacks.length; i++)
805                            callbacks[i](node);
806                    }
807
808                    // Erase the DOM data
809                    ko.utils.domData.clear(node);
810
811                    // Perform cleanup needed by external libraries (currently only jQuery, but can be extended)
812                    ko.utils.domNodeDisposal["cleanExternalData"](node);
813
814                    // Clear any immediate-child comment nodes, as these wouldn't have been found by
815                    // node.getElementsByTagName("*") in cleanNode() (comment nodes aren't elements)
816                    if (cleanableNodeTypesWithDescendants[node.nodeType]) {
817                        cleanNodesInList(node.childNodes, true/*onlyComments*/);
818                    }
819                }
820
821                function cleanNodesInList(nodeList, onlyComments) {
822                    var cleanedNodes = [], lastCleanedNode;
823                    for (var i = 0; i < nodeList.length; i++) {
824                        if (!onlyComments || nodeList[i].nodeType === 8) {
825                            cleanSingleNode(cleanedNodes[cleanedNodes.length] = lastCleanedNode = nodeList[i]);
826                            if (nodeList[i] !== lastCleanedNode) {
827                                while (i-- && ko.utils.arrayIndexOf(cleanedNodes, nodeList[i]) == -1) { }
828                            }
829                        }
830                    }
831                }
832
833                return {
834                    addDisposeCallback: function (node, callback) {
835                        if (typeof callback != "function")
836                            throw new Error("Callback must be a function");
837                        getDisposeCallbacksCollection(node, true).push(callback);
838                    },
839
840                    removeDisposeCallback: function (node, callback) {
841                        var callbacksCollection = getDisposeCallbacksCollection(node, false);
842                        if (callbacksCollection) {
843                            ko.utils.arrayRemoveItem(callbacksCollection, callback);
844                            if (callbacksCollection.length == 0)
845                                destroyCallbacksCollection(node);
846                        }
847                    },
848
849                    cleanNode: function (node) {
850                        ko.dependencyDetection.ignore(function () {
851                            // First clean this node, where applicable
852                            if (cleanableNodeTypes[node.nodeType]) {
853                                cleanSingleNode(node);
854
855                                // ... then its descendants, where applicable
856                                if (cleanableNodeTypesWithDescendants[node.nodeType]) {
857                                    cleanNodesInList(node.getElementsByTagName("*"));
858                                }
859                            }
860                        });
861
862                        return node;
863                    },
864
865                    removeNode: function (node) {
866                        ko.cleanNode(node);
867                        if (node.parentNode)
868                            node.parentNode.removeChild(node);
869                    },
870
871                    "cleanExternalData": function (node) {
872                        // Special support for jQuery here because it's so commonly used.
873                        // Many jQuery plugins (including jquery.tmpl) store data using jQuery's equivalent of domData
874                        // so notify it to tear down any resources associated with the node & descendants here.
875                        if (jQueryInstance && (typeof jQueryInstance['cleanData'] == "function"))
876                            jQueryInstance['cleanData']([node]);
877                    }
878                };
879            })();
880            ko.cleanNode = ko.utils.domNodeDisposal.cleanNode; // Shorthand name for convenience
881            ko.removeNode = ko.utils.domNodeDisposal.removeNode; // Shorthand name for convenience
882            ko.exportSymbol('cleanNode', ko.cleanNode);
883            ko.exportSymbol('removeNode', ko.removeNode);
884            ko.exportSymbol('utils.domNodeDisposal', ko.utils.domNodeDisposal);
885            ko.exportSymbol('utils.domNodeDisposal.addDisposeCallback', ko.utils.domNodeDisposal.addDisposeCallback);
886            ko.exportSymbol('utils.domNodeDisposal.removeDisposeCallback', ko.utils.domNodeDisposal.removeDisposeCallback);
887            (function () {
888                var none = [0, "", ""],
889                    table = [1, "<table>", "</table>"],
890                    tbody = [2, "<table><tbody>", "</tbody></table>"],
891                    tr = [3, "<table><tbody><tr>", "</tr></tbody></table>"],
892                    select = [1, "<select multiple='multiple'>", "</select>"],
893                    lookup = {
894                        'thead': table,
895                        'tbody': table,
896                        'tfoot': table,
897                        'tr': tbody,
898                        'td': tr,
899                        'th': tr,
900                        'option': select,
901                        'optgroup': select
902                    },
903
904                    // This is needed for old IE if you're *not* using either jQuery or innerShiv. Doesn't affect other cases.
905                    mayRequireCreateElementHack = ko.utils.ieVersion <= 8;
906
907                function getWrap(tags) {
908                    var m = tags.match(/^(?:<!--.*?-->\s*?)*?<([a-z]+)[\s>]/);
909                    return (m && lookup[m[1]]) || none;
910                }
911
912                function simpleHtmlParse(html, documentContext) {
913                    documentContext || (documentContext = document);
914                    var windowContext = documentContext['parentWindow'] || documentContext['defaultView'] || window;
915
916                    // Based on jQuery's "clean" function, but only accounting for table-related elements.
917                    // If you have referenced jQuery, this won't be used anyway - KO will use jQuery's "clean" function directly
918
919                    // Note that there's still an issue in IE < 9 whereby it will discard comment nodes that are the first child of
920                    // a descendant node. For example: "<div><!-- mycomment -->abc</div>" will get parsed as "<div>abc</div>"
921                    // This won't affect anyone who has referenced jQuery, and there's always the workaround of inserting a dummy node
922                    // (possibly a text node) in front of the comment. So, KO does not attempt to workaround this IE issue automatically at present.
923
924                    // Trim whitespace, otherwise indexOf won't work as expected
925                    var tags = ko.utils.stringTrim(html).toLowerCase(), div = documentContext.createElement("div"),
926                        wrap = getWrap(tags),
927                        depth = wrap[0];
928
929                    // Go to html and back, then peel off extra wrappers
930                    // Note that we always prefix with some dummy text, because otherwise, IE<9 will strip out leading comment nodes in descendants. Total madness.
931                    var markup = "ignored<div>" + wrap[1] + html + wrap[2] + "</div>";
932                    if (typeof windowContext['innerShiv'] == "function") {
933                        // Note that innerShiv is deprecated in favour of html5shiv. We should consider adding
934                        // support for html5shiv (except if no explicit support is needed, e.g., if html5shiv
935                        // somehow shims the native APIs so it just works anyway)
936                        div.appendChild(windowContext['innerShiv'](markup));
937                    } else {
938                        if (mayRequireCreateElementHack) {
939                            // The document.createElement('my-element') trick to enable custom elements in IE6-8
940                            // only works if we assign innerHTML on an element associated with that document.
941                            documentContext.body.appendChild(div);
942                        }
943
944                        div.innerHTML = markup;
945
946                        if (mayRequireCreateElementHack) {
947                            div.parentNode.removeChild(div);
948                        }
949                    }
950
951                    // Move to the right depth
952                    while (depth--)
953                        div = div.lastChild;
954
955                    return ko.utils.makeArray(div.lastChild.childNodes);
956                }
957
958                function jQueryHtmlParse(html, documentContext) {
959                    // jQuery's "parseHTML" function was introduced in jQuery 1.8.0 and is a documented public API.
960                    if (jQueryInstance['parseHTML']) {
961                        return jQueryInstance['parseHTML'](html, documentContext) || []; // Ensure we always return an array and never null
962                    } else {
963                        // For jQuery < 1.8.0, we fall back on the undocumented internal "clean" function.
964                        var elems = jQueryInstance['clean']([html], documentContext);
965
966                        // As of jQuery 1.7.1, jQuery parses the HTML by appending it to some dummy parent nodes held in an in-memory document fragment.
967                        // Unfortunately, it never clears the dummy parent nodes from the document fragment, so it leaks memory over time.
968                        // Fix this by finding the top-most dummy parent element, and detaching it from its owner fragment.
969                        if (elems && elems[0]) {
970                            // Find the top-most parent element that's a direct child of a document fragment
971                            var elem = elems[0];
972                            while (elem.parentNode && elem.parentNode.nodeType !== 11 /* i.e., DocumentFragment */)
973                                elem = elem.parentNode;
974                            // ... then detach it
975                            if (elem.parentNode)
976                                elem.parentNode.removeChild(elem);
977                        }
978
979                        return elems;
980                    }
981                }
982
983                ko.utils.parseHtmlFragment = function (html, documentContext) {
984                    return jQueryInstance ?
985                        jQueryHtmlParse(html, documentContext) :   // As below, benefit from jQuery's optimisations where possible
986                        simpleHtmlParse(html, documentContext);  // ... otherwise, this simple logic will do in most common cases.
987                };
988
989                ko.utils.parseHtmlForTemplateNodes = function (html, documentContext) {
990                    var nodes = ko.utils.parseHtmlFragment(html, documentContext);
991                    return (nodes.length && nodes[0].parentElement) || ko.utils.moveCleanedNodesToContainerElement(nodes);
992                };
993
994                ko.utils.setHtml = function (node, html) {
995                    ko.utils.emptyDomNode(node);
996
997                    // There's no legitimate reason to display a stringified observable without unwrapping it, so we'll unwrap it
998                    html = ko.utils.unwrapObservable(html);
999
1000                    if ((html !== null) && (html !== undefined)) {
1001                        if (typeof html != 'string')
1002                            html = html.toString();
1003
1004                        // jQuery contains a lot of sophisticated code to parse arbitrary HTML fragments,
1005                        // for example <tr> elements which are not normally allowed to exist on their own.
1006                        // If you've referenced jQuery we'll use that rather than duplicating its code.
1007                        if (jQueryInstance) {
1008                            jQueryInstance(node)['html'](html);
1009                        } else {
1010                            // ... otherwise, use KO's own parsing logic.
1011                            var parsedNodes = ko.utils.parseHtmlFragment(html, node.ownerDocument);
1012                            for (var i = 0; i < parsedNodes.length; i++)
1013                                node.appendChild(parsedNodes[i]);
1014                        }
1015                    }
1016                };
1017            })();
1018
1019            ko.exportSymbol('utils.parseHtmlFragment', ko.utils.parseHtmlFragment);
1020            ko.exportSymbol('utils.setHtml', ko.utils.setHtml);
1021
1022            ko.memoization = (function () {
1023                var memos = {};
1024
1025                function randomMax8HexChars() {
1026                    return (((1 + Math.random()) * 0x100000000) | 0).toString(16).substring(1);
1027                }
1028                function generateRandomId() {
1029                    return randomMax8HexChars() + randomMax8HexChars();
1030                }
1031                function findMemoNodes(rootNode, appendToArray) {
1032                    if (!rootNode)
1033                        return;
1034                    if (rootNode.nodeType == 8) {
1035                        var memoId = ko.memoization.parseMemoText(rootNode.nodeValue);
1036                        if (memoId != null)
1037                            appendToArray.push({ domNode: rootNode, memoId: memoId });
1038                    } else if (rootNode.nodeType == 1) {
1039                        for (var i = 0, childNodes = rootNode.childNodes, j = childNodes.length; i < j; i++)
1040                            findMemoNodes(childNodes[i], appendToArray);
1041                    }
1042                }
1043
1044                return {
1045                    memoize: function (callback) {
1046                        if (typeof callback != "function")
1047                            throw new Error("You can only pass a function to ko.memoization.memoize()");
1048                        var memoId = generateRandomId();
1049                        memos[memoId] = callback;
1050                        return "<!--[ko_memo:" + memoId + "]-->";
1051                    },
1052
1053                    unmemoize: function (memoId, callbackParams) {
1054                        var callback = memos[memoId];
1055                        if (callback === undefined)
1056                            throw new Error("Couldn't find any memo with ID " + memoId + ". Perhaps it's already been unmemoized.");
1057                        try {
1058                            callback.apply(null, callbackParams || []);
1059                            return true;
1060                        }
1061                        finally { delete memos[memoId]; }
1062                    },
1063
1064                    unmemoizeDomNodeAndDescendants: function (domNode, extraCallbackParamsArray) {
1065                        var memos = [];
1066                        findMemoNodes(domNode, memos);
1067                        for (var i = 0, j = memos.length; i < j; i++) {
1068                            var node = memos[i].domNode;
1069                            var combinedParams = [node];
1070                            if (extraCallbackParamsArray)
1071                                ko.utils.arrayPushAll(combinedParams, extraCallbackParamsArray);
1072                            ko.memoization.unmemoize(memos[i].memoId, combinedParams);
1073                            node.nodeValue = ""; // Neuter this node so we don't try to unmemoize it again
1074                            if (node.parentNode)
1075                                node.parentNode.removeChild(node); // If possible, erase it totally (not always possible - someone else might just hold a reference to it then call unmemoizeDomNodeAndDescendants again)
1076                        }
1077                    },
1078
1079                    parseMemoText: function (memoText) {
1080                        var match = memoText.match(/^\[ko_memo\:(.*?)\]$/);
1081                        return match ? match[1] : null;
1082                    }
1083                };
1084            })();
1085
1086            ko.exportSymbol('memoization', ko.memoization);
1087            ko.exportSymbol('memoization.memoize', ko.memoization.memoize);
1088            ko.exportSymbol('memoization.unmemoize', ko.memoization.unmemoize);
1089            ko.exportSymbol('memoization.parseMemoText', ko.memoization.parseMemoText);
1090            ko.exportSymbol('memoization.unmemoizeDomNodeAndDescendants', ko.memoization.unmemoizeDomNodeAndDescendants);
1091            ko.tasks = (function () {
1092                var scheduler,
1093                    taskQueue = [],
1094                    taskQueueLength = 0,
1095                    nextHandle = 1,
1096                    nextIndexToProcess = 0;
1097
1098                if (window['MutationObserver']) {
1099                    // Chrome 27+, Firefox 14+, IE 11+, Opera 15+, Safari 6.1+
1100                    // From https://github.com/petkaantonov/bluebird * Copyright (c) 2014 Petka Antonov * License: MIT
1101                    scheduler = (function (callback) {
1102                        var div = document.createElement("div");
1103                        new MutationObserver(callback).observe(div, { attributes: true });
1104                        return function () { div.classList.toggle("foo"); };
1105                    })(scheduledProcess);
1106                } else if (document && "onreadystatechange" in document.createElement("script")) {
1107                    // IE 6-10
1108                    // From https://github.com/YuzuJS/setImmediate * Copyright (c) 2012 Barnesandnoble.com, llc, Donavon West, and Domenic Denicola * License: MIT
1109                    scheduler = function (callback) {
1110                        var script = document.createElement("script");
1111                        script.onreadystatechange = function () {
1112                            script.onreadystatechange = null;
1113                            document.documentElement.removeChild(script);
1114                            script = null;
1115                            callback();
1116                        };
1117                        document.documentElement.appendChild(script);
1118                    };
1119                } else {
1120                    scheduler = function (callback) {
1121                        setTimeout(callback, 0);
1122                    };
1123                }
1124
1125                function processTasks() {
1126                    if (taskQueueLength) {
1127                        // Each mark represents the end of a logical group of tasks and the number of these groups is
1128                        // limited to prevent unchecked recursion.
1129                        var mark = taskQueueLength, countMarks = 0;
1130
1131                        // nextIndexToProcess keeps track of where we are in the queue; processTasks can be called recursively without issue
1132                        for (var task; nextIndexToProcess < taskQueueLength;) {
1133                            if (task = taskQueue[nextIndexToProcess++]) {
1134                                if (nextIndexToProcess > mark) {
1135                                    if (++countMarks >= 5000) {
1136                                        nextIndexToProcess = taskQueueLength;   // skip all tasks remaining in the queue since any of them could be causing the recursion
1137                                        ko.utils.deferError(Error("'Too much recursion' after processing " + countMarks + " task groups."));
1138                                        break;
1139                                    }
1140                                    mark = taskQueueLength;
1141                                }
1142                                try {
1143                                    task();
1144                                } catch (ex) {
1145                                    ko.utils.deferError(ex);
1146                                }
1147                            }
1148                        }
1149                    }
1150                }
1151
1152                function scheduledProcess() {
1153                    processTasks();
1154
1155                    // Reset the queue
1156                    nextIndexToProcess = taskQueueLength = taskQueue.length = 0;
1157                }
1158
1159                function scheduleTaskProcessing() {
1160                    ko.tasks['scheduler'](scheduledProcess);
1161                }
1162
1163                var tasks = {
1164                    'scheduler': scheduler,     // Allow overriding the scheduler
1165
1166                    schedule: function (func) {
1167                        if (!taskQueueLength) {
1168                            scheduleTaskProcessing();
1169                        }
1170
1171                        taskQueue[taskQueueLength++] = func;
1172                        return nextHandle++;
1173                    },
1174
1175                    cancel: function (handle) {
1176                        var index = handle - (nextHandle - taskQueueLength);
1177                        if (index >= nextIndexToProcess && index < taskQueueLength) {
1178                            taskQueue[index] = null;
1179                        }
1180                    },
1181
1182                    // For testing only: reset the queue and return the previous queue length
1183                    'resetForTesting': function () {
1184                        var length = taskQueueLength - nextIndexToProcess;
1185                        nextIndexToProcess = taskQueueLength = taskQueue.length = 0;
1186                        return length;
1187                    },
1188
1189                    runEarly: processTasks
1190                };
1191
1192                return tasks;
1193            })();
1194
1195            ko.exportSymbol('tasks', ko.tasks);
1196            ko.exportSymbol('tasks.schedule', ko.tasks.schedule);
1197            //ko.exportSymbol('tasks.cancel', ko.tasks.cancel);  "cancel" isn't minified
1198            ko.exportSymbol('tasks.runEarly', ko.tasks.runEarly);
1199            ko.extenders = {
1200                'throttle': function (target, timeout) {
1201                    // Throttling means two things:
1202
1203                    // (1) For dependent observables, we throttle *evaluations* so that, no matter how fast its dependencies
1204                    //     notify updates, the target doesn't re-evaluate (and hence doesn't notify) faster than a certain rate
1205                    target['throttleEvaluation'] = timeout;
1206
1207                    // (2) For writable targets (observables, or writable dependent observables), we throttle *writes*
1208                    //     so the target cannot change value synchronously or faster than a certain rate
1209                    var writeTimeoutInstance = null;
1210                    return ko.dependentObservable({
1211                        'read': target,
1212                        'write': function (value) {
1213                            clearTimeout(writeTimeoutInstance);
1214                            writeTimeoutInstance = ko.utils.setTimeout(function () {
1215                                target(value);
1216                            }, timeout);
1217                        }
1218                    });
1219                },
1220
1221                'rateLimit': function (target, options) {
1222                    var timeout, method, limitFunction;
1223
1224                    if (typeof options == 'number') {
1225                        timeout = options;
1226                    } else {
1227                        timeout = options['timeout'];
1228                        method = options['method'];
1229                    }
1230
1231                    // rateLimit supersedes deferred updates
1232                    target._deferUpdates = false;
1233
1234                    limitFunction = typeof method == 'function' ? method : method == 'notifyWhenChangesStop' ? debounce : throttle;
1235                    target.limit(function (callback) {
1236                        return limitFunction(callback, timeout, options);
1237                    });
1238                },
1239
1240                'deferred': function (target, options) {
1241                    if (options !== true) {
1242                        throw new Error('The \'deferred\' extender only accepts the value \'true\', because it is not supported to turn deferral off once enabled.')
1243                    }
1244
1245                    if (!target._deferUpdates) {
1246                        target._deferUpdates = true;
1247                        target.limit(function (callback) {
1248                            var handle,
1249                                ignoreUpdates = false;
1250                            return function () {
1251                                if (!ignoreUpdates) {
1252                                    ko.tasks.cancel(handle);
1253                                    handle = ko.tasks.schedule(callback);
1254
1255                                    try {
1256                                        ignoreUpdates = true;
1257                                        target['notifySubscribers'](undefined, 'dirty');
1258                                    } finally {
1259                                        ignoreUpdates = false;
1260                                    }
1261                                }
1262                            };
1263                        });
1264                    }
1265                },
1266
1267                'notify': function (target, notifyWhen) {
1268                    target["equalityComparer"] = notifyWhen == "always" ?
1269                        null :  // null equalityComparer means to always notify
1270                        valuesArePrimitiveAndEqual;
1271                }
1272            };
1273
1274            var primitiveTypes = { 'undefined': 1, 'boolean': 1, 'number': 1, 'string': 1 };
1275            function valuesArePrimitiveAndEqual(a, b) {
1276                var oldValueIsPrimitive = (a === null) || (typeof (a) in primitiveTypes);
1277                return oldValueIsPrimitive ? (a === b) : false;
1278            }
1279
1280            function throttle(callback, timeout) {
1281                var timeoutInstance;
1282                return function () {
1283                    if (!timeoutInstance) {
1284                        timeoutInstance = ko.utils.setTimeout(function () {
1285                            timeoutInstance = undefined;
1286                            callback();
1287                        }, timeout);
1288                    }
1289                };
1290            }
1291
1292            function debounce(callback, timeout) {
1293                var timeoutInstance;
1294                return function () {
1295                    clearTimeout(timeoutInstance);
1296                    timeoutInstance = ko.utils.setTimeout(callback, timeout);
1297                };
1298            }
1299
1300            function applyExtenders(requestedExtenders) {
1301                var target = this;
1302                if (requestedExtenders) {
1303                    ko.utils.objectForEach(requestedExtenders, function (key, value) {
1304                        var extenderHandler = ko.extenders[key];
1305                        if (typeof extenderHandler == 'function') {
1306                            target = extenderHandler(target, value) || target;
1307                        }
1308                    });
1309                }
1310                return target;
1311            }
1312
1313            ko.exportSymbol('extenders', ko.extenders);
1314
1315            ko.subscription = function (target, callback, disposeCallback) {
1316                this._target = target;
1317                this._callback = callback;
1318                this._disposeCallback = disposeCallback;
1319                this._isDisposed = false;
1320                this._node = null;
1321                this._domNodeDisposalCallback = null;
1322                ko.exportProperty(this, 'dispose', this.dispose);
1323                ko.exportProperty(this, 'disposeWhenNodeIsRemoved', this.disposeWhenNodeIsRemoved);
1324            };
1325            ko.subscription.prototype.dispose = function () {
1326                var self = this;
1327                if (!self._isDisposed) {
1328                    if (self._domNodeDisposalCallback) {
1329                        ko.utils.domNodeDisposal.removeDisposeCallback(self._node, self._domNodeDisposalCallback);
1330                    }
1331                    self._isDisposed = true;
1332                    self._disposeCallback();
1333
1334                    self._target = self._callback = self._disposeCallback = self._node = self._domNodeDisposalCallback = null;
1335                }
1336            };
1337            ko.subscription.prototype.disposeWhenNodeIsRemoved = function (node) {
1338                this._node = node;
1339                ko.utils.domNodeDisposal.addDisposeCallback(node, this._domNodeDisposalCallback = this.dispose.bind(this));
1340            };
1341
1342            ko.subscribable = function () {
1343                ko.utils.setPrototypeOfOrExtend(this, ko_subscribable_fn);
1344                ko_subscribable_fn.init(this);
1345            }
1346
1347            var defaultEvent = "change";
1348
1349            // Moved out of "limit" to avoid the extra closure
1350            function limitNotifySubscribers(value, event) {
1351                if (!event || event === defaultEvent) {
1352                    this._limitChange(value);
1353                } else if (event === 'beforeChange') {
1354                    this._limitBeforeChange(value);
1355                } else {
1356                    this._origNotifySubscribers(value, event);
1357                }
1358            }
1359
1360            var ko_subscribable_fn = {
1361                init: function (instance) {
1362                    instance._subscriptions = { "change": [] };
1363                    instance._versionNumber = 1;
1364                },
1365
1366                subscribe: function (callback, callbackTarget, event) {
1367                    var self = this;
1368
1369                    event = event || defaultEvent;
1370                    var boundCallback = callbackTarget ? callback.bind(callbackTarget) : callback;
1371
1372                    var subscription = new ko.subscription(self, boundCallback, function () {
1373                        ko.utils.arrayRemoveItem(self._subscriptions[event], subscription);
1374                        if (self.afterSubscriptionRemove)
1375                            self.afterSubscriptionRemove(event);
1376                    });
1377
1378                    if (self.beforeSubscriptionAdd)
1379                        self.beforeSubscriptionAdd(event);
1380
1381                    if (!self._subscriptions[event])
1382                        self._subscriptions[event] = [];
1383                    self._subscriptions[event].push(subscription);
1384
1385                    return subscription;
1386                },
1387
1388                "notifySubscribers": function (valueToNotify, event) {
1389                    event = event || defaultEvent;
1390                    if (event === defaultEvent) {
1391                        this.updateVersion();
1392                    }
1393                    if (this.hasSubscriptionsForEvent(event)) {
1394                        var subs = event === defaultEvent && this._changeSubscriptions || this._subscriptions[event].slice(0);
1395                        try {
1396                            ko.dependencyDetection.begin(); // Begin suppressing dependency detection (by setting the top frame to undefined)
1397                            for (var i = 0, subscription; subscription = subs[i]; ++i) {
1398                                // In case a subscription was disposed during the arrayForEach cycle, check
1399                                // for isDisposed on each subscription before invoking its callback
1400                                if (!subscription._isDisposed)
1401                                    subscription._callback(valueToNotify);
1402                            }
1403                        } finally {
1404                            ko.dependencyDetection.end(); // End suppressing dependency detection
1405                        }
1406                    }
1407                },
1408
1409                getVersion: function () {
1410                    return this._versionNumber;
1411                },
1412
1413                hasChanged: function (versionToCheck) {
1414                    return this.getVersion() !== versionToCheck;
1415                },
1416
1417                updateVersion: function () {
1418                    ++this._versionNumber;
1419                },
1420
1421                limit: function (limitFunction) {
1422                    var self = this, selfIsObservable = ko.isObservable(self),
1423                        ignoreBeforeChange, notifyNextChange, previousValue, pendingValue, didUpdate,
1424                        beforeChange = 'beforeChange';
1425
1426                    if (!self._origNotifySubscribers) {
1427                        self._origNotifySubscribers = self["notifySubscribers"];
1428                        self["notifySubscribers"] = limitNotifySubscribers;
1429                    }
1430
1431                    var finish = limitFunction(function () {
1432                        self._notificationIsPending = false;
1433
1434                        // If an observable provided a reference to itself, access it to get the latest value.
1435                        // This allows computed observables to delay calculating their value until needed.
1436                        if (selfIsObservable && pendingValue === self) {
1437                            pendingValue = self._evalIfChanged ? self._evalIfChanged() : self();
1438                        }
1439                        var shouldNotify = notifyNextChange || (didUpdate && self.isDifferent(previousValue, pendingValue));
1440
1441                        didUpdate = notifyNextChange = ignoreBeforeChange = false;
1442
1443                        if (shouldNotify) {
1444                            self._origNotifySubscribers(previousValue = pendingValue);
1445                        }
1446                    });
1447
1448                    self._limitChange = function (value, isDirty) {
1449                        if (!isDirty || !self._notificationIsPending) {
1450                            didUpdate = !isDirty;
1451                        }
1452                        self._changeSubscriptions = self._subscriptions[defaultEvent].slice(0);
1453                        self._notificationIsPending = ignoreBeforeChange = true;
1454                        pendingValue = value;
1455                        finish();
1456                    };
1457                    self._limitBeforeChange = function (value) {
1458                        if (!ignoreBeforeChange) {
1459                            previousValue = value;
1460                            self._origNotifySubscribers(value, beforeChange);
1461                        }
1462                    };
1463                    self._recordUpdate = function () {
1464                        didUpdate = true;
1465                    };
1466                    self._notifyNextChangeIfValueIsDifferent = function () {
1467                        if (self.isDifferent(previousValue, self.peek(true /*evaluate*/))) {
1468                            notifyNextChange = true;
1469                        }
1470                    };
1471                },
1472
1473                hasSubscriptionsForEvent: function (event) {
1474                    return this._subscriptions[event] && this._subscriptions[event].length;
1475                },
1476
1477                getSubscriptionsCount: function (event) {
1478                    if (event) {
1479                        return this._subscriptions[event] && this._subscriptions[event].length || 0;
1480                    } else {
1481                        var total = 0;
1482                        ko.utils.objectForEach(this._subscriptions, function (eventName, subscriptions) {
1483                            if (eventName !== 'dirty')
1484                                total += subscriptions.length;
1485                        });
1486                        return total;
1487                    }
1488                },
1489
1490                isDifferent: function (oldValue, newValue) {
1491                    return !this['equalityComparer'] || !this['equalityComparer'](oldValue, newValue);
1492                },
1493
1494                toString: function () {
1495                    return '[object Object]'
1496                },
1497
1498                extend: applyExtenders
1499            };
1500
1501            ko.exportProperty(ko_subscribable_fn, 'init', ko_subscribable_fn.init);
1502            ko.exportProperty(ko_subscribable_fn, 'subscribe', ko_subscribable_fn.subscribe);
1503            ko.exportProperty(ko_subscribable_fn, 'extend', ko_subscribable_fn.extend);
1504            ko.exportProperty(ko_subscribable_fn, 'getSubscriptionsCount', ko_subscribable_fn.getSubscriptionsCount);
1505
1506            // For browsers that support proto assignment, we overwrite the prototype of each
1507            // observable instance. Since observables are functions, we need Function.prototype
1508            // to still be in the prototype chain.
1509            if (ko.utils.canSetPrototype) {
1510                ko.utils.setPrototypeOf(ko_subscribable_fn, Function.prototype);
1511            }
1512
1513            ko.subscribable['fn'] = ko_subscribable_fn;
1514
1515
1516            ko.isSubscribable = function (instance) {
1517                return instance != null && typeof instance.subscribe == "function" && typeof instance["notifySubscribers"] == "function";
1518            };
1519
1520            ko.exportSymbol('subscribable', ko.subscribable);
1521            ko.exportSymbol('isSubscribable', ko.isSubscribable);
1522
1523            ko.computedContext = ko.dependencyDetection = (function () {
1524                var outerFrames = [],
1525                    currentFrame,
1526                    lastId = 0;
1527
1528                // Return a unique ID that can be assigned to an observable for dependency tracking.
1529                // Theoretically, you could eventually overflow the number storage size, resulting
1530                // in duplicate IDs. But in JavaScript, the largest exact integral value is 2^53
1531                // or 9,007,199,254,740,992. If you created 1,000,000 IDs per second, it would
1532                // take over 285 years to reach that number.
1533                // Reference http://blog.vjeux.com/2010/javascript/javascript-max_int-number-limits.html
1534                function getId() {
1535                    return ++lastId;
1536                }
1537
1538                function begin(options) {
1539                    outerFrames.push(currentFrame);
1540                    currentFrame = options;
1541                }
1542
1543                function end() {
1544                    currentFrame = outerFrames.pop();
1545                }
1546
1547                return {
1548                    begin: begin,
1549
1550                    end: end,
1551
1552                    registerDependency: function (subscribable) {
1553                        if (currentFrame) {
1554                            if (!ko.isSubscribable(subscribable))
1555                                throw new Error("Only subscribable things can act as dependencies");
1556                            currentFrame.callback.call(currentFrame.callbackTarget, subscribable, subscribable._id || (subscribable._id = getId()));
1557                        }
1558                    },
1559
1560                    ignore: function (callback, callbackTarget, callbackArgs) {
1561                        try {
1562                            begin();
1563                            return callback.apply(callbackTarget, callbackArgs || []);
1564                        } finally {
1565                            end();
1566                        }
1567                    },
1568
1569                    getDependenciesCount: function () {
1570                        if (currentFrame)
1571                            return currentFrame.computed.getDependenciesCount();
1572                    },
1573
1574                    getDependencies: function () {
1575                        if (currentFrame)
1576                            return currentFrame.computed.getDependencies();
1577                    },
1578
1579                    isInitial: function () {
1580                        if (currentFrame)
1581                            return currentFrame.isInitial;
1582                    },
1583
1584                    computed: function () {
1585                        if (currentFrame)
1586                            return currentFrame.computed;
1587                    }
1588                };
1589            })();
1590
1591            ko.exportSymbol('computedContext', ko.computedContext);
1592            ko.exportSymbol('computedContext.getDependenciesCount', ko.computedContext.getDependenciesCount);
1593            ko.exportSymbol('computedContext.getDependencies', ko.computedContext.getDependencies);
1594            ko.exportSymbol('computedContext.isInitial', ko.computedContext.isInitial);
1595            ko.exportSymbol('computedContext.registerDependency', ko.computedContext.registerDependency);
1596
1597            ko.exportSymbol('ignoreDependencies', ko.ignoreDependencies = ko.dependencyDetection.ignore);
1598            var observableLatestValue = ko.utils.createSymbolOrString('_latestValue');
1599
1600            ko.observable = function (initialValue) {
1601                function observable() {
1602                    if (arguments.length > 0) {
1603                        // Write
1604
1605                        // Ignore writes if the value hasn't changed
1606                        if (observable.isDifferent(observable[observableLatestValue], arguments[0])) {
1607                            observable.valueWillMutate();
1608                            observable[observableLatestValue] = arguments[0];
1609                            observable.valueHasMutated();
1610                        }
1611                        return this; // Permits chained assignments
1612                    }
1613                    else {
1614                        // Read
1615                        ko.dependencyDetection.registerDependency(observable); // The caller only needs to be notified of changes if they did a "read" operation
1616                        return observable[observableLatestValue];
1617                    }
1618                }
1619
1620                observable[observableLatestValue] = initialValue;
1621
1622                // Inherit from 'subscribable'
1623                if (!ko.utils.canSetPrototype) {
1624                    // 'subscribable' won't be on the prototype chain unless we put it there directly
1625                    ko.utils.extend(observable, ko.subscribable['fn']);
1626                }
1627                ko.subscribable['fn'].init(observable);
1628
1629                // Inherit from 'observable'
1630                ko.utils.setPrototypeOfOrExtend(observable, observableFn);
1631
1632                if (ko.options['deferUpdates']) {
1633                    ko.extenders['deferred'](observable, true);
1634                }
1635
1636                return observable;
1637            }
1638
1639            // Define prototype for observables
1640            var observableFn = {
1641                'equalityComparer': valuesArePrimitiveAndEqual,
1642                peek: function () { return this[observableLatestValue]; },
1643                valueHasMutated: function () {
1644                    this['notifySubscribers'](this[observableLatestValue], 'spectate');
1645                    this['notifySubscribers'](this[observableLatestValue]);
1646                },
1647                valueWillMutate: function () { this['notifySubscribers'](this[observableLatestValue], 'beforeChange'); }
1648            };
1649
1650            // Note that for browsers that don't support proto assignment, the
1651            // inheritance chain is created manually in the ko.observable constructor
1652            if (ko.utils.canSetPrototype) {
1653                ko.utils.setPrototypeOf(observableFn, ko.subscribable['fn']);
1654            }
1655
1656            var protoProperty = ko.observable.protoProperty = '__ko_proto__';
1657            observableFn[protoProperty] = ko.observable;
1658
1659            ko.isObservable = function (instance) {
1660                var proto = typeof instance == 'function' && instance[protoProperty];
1661                if (proto && proto !== observableFn[protoProperty] && proto !== ko.computed['fn'][protoProperty]) {
1662                    throw Error("Invalid object that looks like an observable; possibly from another Knockout instance");
1663                }
1664                return !!proto;
1665            };
1666
1667            ko.isWriteableObservable = function (instance) {
1668                return (typeof instance == 'function' && (
1669                    (instance[protoProperty] === observableFn[protoProperty]) ||  // Observable
1670                    (instance[protoProperty] === ko.computed['fn'][protoProperty] && instance.hasWriteFunction)));   // Writable computed observable
1671            };
1672
1673            ko.exportSymbol('observable', ko.observable);
1674            ko.exportSymbol('isObservable', ko.isObservable);
1675            ko.exportSymbol('isWriteableObservable', ko.isWriteableObservable);
1676            ko.exportSymbol('isWritableObservable', ko.isWriteableObservable);
1677            ko.exportSymbol('observable.fn', observableFn);
1678            ko.exportProperty(observableFn, 'peek', observableFn.peek);
1679            ko.exportProperty(observableFn, 'valueHasMutated', observableFn.valueHasMutated);
1680            ko.exportProperty(observableFn, 'valueWillMutate', observableFn.valueWillMutate);
1681            ko.observableArray = function (initialValues) {
1682                initialValues = initialValues || [];
1683
1684                if (typeof initialValues != 'object' || !('length' in initialValues))
1685                    throw new Error("The argument passed when initializing an observable array must be an array, or null, or undefined.");
1686
1687                var result = ko.observable(initialValues);
1688                ko.utils.setPrototypeOfOrExtend(result, ko.observableArray['fn']);
1689                return result.extend({ 'trackArrayChanges': true });
1690            };
1691
1692            ko.observableArray['fn'] = {
1693                'remove': function (valueOrPredicate) {
1694                    var underlyingArray = this.peek();
1695                    var removedValues = [];
1696                    var predicate = typeof valueOrPredicate == "function" && !ko.isObservable(valueOrPredicate) ? valueOrPredicate : function (value) { return value === valueOrPredicate; };
1697                    for (var i = 0; i < underlyingArray.length; i++) {
1698                        var value = underlyingArray[i];
1699                        if (predicate(value)) {
1700                            if (removedValues.length === 0) {
1701                                this.valueWillMutate();
1702                            }
1703                            if (underlyingArray[i] !== value) {
1704                                throw Error("Array modified during remove; cannot remove item");
1705                            }
1706                            removedValues.push(value);
1707                            underlyingArray.splice(i, 1);
1708                            i--;
1709                        }
1710                    }
1711                    if (removedValues.length) {
1712                        this.valueHasMutated();
1713                    }
1714                    return removedValues;
1715                },
1716
1717                'removeAll': function (arrayOfValues) {
1718                    // If you passed zero args, we remove everything
1719                    if (arrayOfValues === undefined) {
1720                        var underlyingArray = this.peek();
1721                        var allValues = underlyingArray.slice(0);
1722                        this.valueWillMutate();
1723                        underlyingArray.splice(0, underlyingArray.length);
1724                        this.valueHasMutated();
1725                        return allValues;
1726                    }
1727                    // If you passed an arg, we interpret it as an array of entries to remove
1728                    if (!arrayOfValues)
1729                        return [];
1730                    return this['remove'](function (value) {
1731                        return ko.utils.arrayIndexOf(arrayOfValues, value) >= 0;
1732                    });
1733                },
1734
1735                'destroy': function (valueOrPredicate) {
1736                    var underlyingArray = this.peek();
1737                    var predicate = typeof valueOrPredicate == "function" && !ko.isObservable(valueOrPredicate) ? valueOrPredicate : function (value) { return value === valueOrPredicate; };
1738                    this.valueWillMutate();
1739                    for (var i = underlyingArray.length - 1; i >= 0; i--) {
1740                        var value = underlyingArray[i];
1741                        if (predicate(value))
1742                            value["_destroy"] = true;
1743                    }
1744                    this.valueHasMutated();
1745                },
1746
1747                'destroyAll': function (arrayOfValues) {
1748                    // If you passed zero args, we destroy everything
1749                    if (arrayOfValues === undefined)
1750                        return this['destroy'](function () { return true });
1751
1752                    // If you passed an arg, we interpret it as an array of entries to destroy
1753                    if (!arrayOfValues)
1754                        return [];
1755                    return this['destroy'](function (value) {
1756                        return ko.utils.arrayIndexOf(arrayOfValues, value) >= 0;
1757                    });
1758                },
1759
1760                'indexOf': function (item) {
1761                    var underlyingArray = this();
1762                    return ko.utils.arrayIndexOf(underlyingArray, item);
1763                },
1764
1765                'replace': function (oldItem, newItem) {
1766                    var index = this['indexOf'](oldItem);
1767                    if (index >= 0) {
1768                        this.valueWillMutate();
1769                        this.peek()[index] = newItem;
1770                        this.valueHasMutated();
1771                    }
1772                },
1773
1774                'sorted': function (compareFunction) {
1775                    var arrayCopy = this().slice(0);
1776                    return compareFunction ? arrayCopy.sort(compareFunction) : arrayCopy.sort();
1777                },
1778
1779                'reversed': function () {
1780                    return this().slice(0).reverse();
1781                }
1782            };
1783
1784            // Note that for browsers that don't support proto assignment, the
1785            // inheritance chain is created manually in the ko.observableArray constructor
1786            if (ko.utils.canSetPrototype) {
1787                ko.utils.setPrototypeOf(ko.observableArray['fn'], ko.observable['fn']);
1788            }
1789
1790            // Populate ko.observableArray.fn with read/write functions from native arrays
1791            // Important: Do not add any additional functions here that may reasonably be used to *read* data from the array
1792            // because we'll eval them without causing subscriptions, so ko.computed output could end up getting stale
1793            ko.utils.arrayForEach(["pop", "push", "reverse", "shift", "sort", "splice", "unshift"], function (methodName) {
1794                ko.observableArray['fn'][methodName] = function () {
1795                    // Use "peek" to avoid creating a subscription in any computed that we're executing in the context of
1796                    // (for consistency with mutating regular observables)
1797                    var underlyingArray = this.peek();
1798                    this.valueWillMutate();
1799                    this.cacheDiffForKnownOperation(underlyingArray, methodName, arguments);
1800                    var methodCallResult = underlyingArray[methodName].apply(underlyingArray, arguments);
1801                    this.valueHasMutated();
1802                    // The native sort and reverse methods return a reference to the array, but it makes more sense to return the observable array instead.
1803                    return methodCallResult === underlyingArray ? this : methodCallResult;
1804                };
1805            });
1806
1807            // Populate ko.observableArray.fn with read-only functions from native arrays
1808            ko.utils.arrayForEach(["slice"], function (methodName) {
1809                ko.observableArray['fn'][methodName] = function () {
1810                    var underlyingArray = this();
1811                    return underlyingArray[methodName].apply(underlyingArray, arguments);
1812                };
1813            });
1814
1815            ko.isObservableArray = function (instance) {
1816                return ko.isObservable(instance)
1817                    && typeof instance["remove"] == "function"
1818                    && typeof instance["push"] == "function";
1819            };
1820
1821            ko.exportSymbol('observableArray', ko.observableArray);
1822            ko.exportSymbol('isObservableArray', ko.isObservableArray);
1823            var arrayChangeEventName = 'arrayChange';
1824            ko.extenders['trackArrayChanges'] = function (target, options) {
1825                // Use the provided options--each call to trackArrayChanges overwrites the previously set options
1826                target.compareArrayOptions = {};
1827                if (options && typeof options == "object") {
1828                    ko.utils.extend(target.compareArrayOptions, options);
1829                }
1830                target.compareArrayOptions['sparse'] = true;
1831
1832                // Only modify the target observable once
1833                if (target.cacheDiffForKnownOperation) {
1834                    return;
1835                }
1836                var trackingChanges = false,
1837                    cachedDiff = null,
1838                    changeSubscription,
1839                    spectateSubscription,
1840                    pendingChanges = 0,
1841                    previousContents,
1842                    underlyingBeforeSubscriptionAddFunction = target.beforeSubscriptionAdd,
1843                    underlyingAfterSubscriptionRemoveFunction = target.afterSubscriptionRemove;
1844
1845                // Watch "subscribe" calls, and for array change events, ensure change tracking is enabled
1846                target.beforeSubscriptionAdd = function (event) {
1847                    if (underlyingBeforeSubscriptionAddFunction) {
1848                        underlyingBeforeSubscriptionAddFunction.call(target, event);
1849                    }
1850                    if (event === arrayChangeEventName) {
1851                        trackChanges();
1852                    }
1853                };
1854                // Watch "dispose" calls, and for array change events, ensure change tracking is disabled when all are disposed
1855                target.afterSubscriptionRemove = function (event) {
1856                    if (underlyingAfterSubscriptionRemoveFunction) {
1857                        underlyingAfterSubscriptionRemoveFunction.call(target, event);
1858                    }
1859                    if (event === arrayChangeEventName && !target.hasSubscriptionsForEvent(arrayChangeEventName)) {
1860                        if (changeSubscription) {
1861                            changeSubscription.dispose();
1862                        }
1863                        if (spectateSubscription) {
1864                            spectateSubscription.dispose();
1865                        }
1866                        spectateSubscription = changeSubscription = null;
1867                        trackingChanges = false;
1868                        previousContents = undefined;
1869                    }
1870                };
1871
1872                function trackChanges() {
1873                    if (trackingChanges) {
1874                        // Whenever there's a new subscription and there are pending notifications, make sure all previous
1875                        // subscriptions are notified of the change so that all subscriptions are in sync.
1876                        notifyChanges();
1877                        return;
1878                    }
1879
1880                    trackingChanges = true;
1881
1882                    // Track how many times the array actually changed value
1883                    spectateSubscription = target.subscribe(function () {
1884                        ++pendingChanges;
1885                    }, null, "spectate");
1886
1887                    // Each time the array changes value, capture a clone so that on the next
1888                    // change it's possible to produce a diff
1889                    previousContents = [].concat(target.peek() || []);
1890                    cachedDiff = null;
1891                    changeSubscription = target.subscribe(notifyChanges);
1892
1893                    function notifyChanges() {
1894                        if (pendingChanges) {
1895                            // Make a copy of the current contents and ensure it's an array
1896                            var currentContents = [].concat(target.peek() || []), changes;
1897
1898                            // Compute the diff and issue notifications, but only if someone is listening
1899                            if (target.hasSubscriptionsForEvent(arrayChangeEventName)) {
1900                                changes = getChanges(previousContents, currentContents);
1901                            }
1902
1903                            // Eliminate references to the old, removed items, so they can be GCed
1904                            previousContents = currentContents;
1905                            cachedDiff = null;
1906                            pendingChanges = 0;
1907
1908                            if (changes && changes.length) {
1909                                target['notifySubscribers'](changes, arrayChangeEventName);
1910                            }
1911                        }
1912                    }
1913                }
1914
1915                function getChanges(previousContents, currentContents) {
1916                    // We try to re-use cached diffs.
1917                    // The scenarios where pendingChanges > 1 are when using rate limiting or deferred updates,
1918                    // which without this check would not be compatible with arrayChange notifications. Normally,
1919                    // notifications are issued immediately so we wouldn't be queueing up more than one.
1920                    if (!cachedDiff || pendingChanges > 1) {
1921                        cachedDiff = ko.utils.compareArrays(previousContents, currentContents, target.compareArrayOptions);
1922                    }
1923
1924                    return cachedDiff;
1925                }
1926
1927                target.cacheDiffForKnownOperation = function (rawArray, operationName, args) {
1928                    // Only run if we're currently tracking changes for this observable array
1929                    // and there aren't any pending deferred notifications.
1930                    if (!trackingChanges || pendingChanges) {
1931                        return;
1932                    }
1933                    var diff = [],
1934                        arrayLength = rawArray.length,
1935                        argsLength = args.length,
1936                        offset = 0;
1937
1938                    function pushDiff(status, value, index) {
1939                        return diff[diff.length] = { 'status': status, 'value': value, 'index': index };
1940                    }
1941                    switch (operationName) {
1942                        case 'push':
1943                            offset = arrayLength;
1944                        case 'unshift':
1945                            for (var index = 0; index < argsLength; index++) {
1946                                pushDiff('added', args[index], offset + index);
1947                            }
1948                            break;
1949
1950                        case 'pop':
1951                            offset = arrayLength - 1;
1952                        case 'shift':
1953                            if (arrayLength) {
1954                                pushDiff('deleted', rawArray[offset], offset);
1955                            }
1956                            break;
1957
1958                        case 'splice':
1959                            // Negative start index means 'from end of array'. After that we clamp to [0...arrayLength].
1960                            // See https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array/splice
1961                            var startIndex = Math.min(Math.max(0, args[0] < 0 ? arrayLength + args[0] : args[0]), arrayLength),
1962                                endDeleteIndex = argsLength === 1 ? arrayLength : Math.min(startIndex + (args[1] || 0), arrayLength),
1963                                endAddIndex = startIndex + argsLength - 2,
1964                                endIndex = Math.max(endDeleteIndex, endAddIndex),
1965                                additions = [], deletions = [];
1966                            for (var index = startIndex, argsIndex = 2; index < endIndex; ++index, ++argsIndex) {
1967                                if (index < endDeleteIndex)
1968                                    deletions.push(pushDiff('deleted', rawArray[index], index));
1969                                if (index < endAddIndex)
1970                                    additions.push(pushDiff('added', args[argsIndex], index));
1971                            }
1972                            ko.utils.findMovesInArrayComparison(deletions, additions);
1973                            break;
1974
1975                        default:
1976                            return;
1977                    }
1978                    cachedDiff = diff;
1979                };
1980            };
1981            var computedState = ko.utils.createSymbolOrString('_state');
1982
1983            ko.computed = ko.dependentObservable = function (evaluatorFunctionOrOptions, evaluatorFunctionTarget, options) {
1984                if (typeof evaluatorFunctionOrOptions === "object") {
1985                    // Single-parameter syntax - everything is on this "options" param
1986                    options = evaluatorFunctionOrOptions;
1987                } else {
1988                    // Multi-parameter syntax - construct the options according to the params passed
1989                    options = options || {};
1990                    if (evaluatorFunctionOrOptions) {
1991                        options["read"] = evaluatorFunctionOrOptions;
1992                    }
1993                }
1994                if (typeof options["read"] != "function")
1995                    throw Error("Pass a function that returns the value of the ko.computed");
1996
1997                var writeFunction = options["write"];
1998                var state = {
1999                    latestValue: undefined,
2000                    isStale: true,
2001                    isDirty: true,
2002                    isBeingEvaluated: false,
2003                    suppressDisposalUntilDisposeWhenReturnsFalse: false,
2004                    isDisposed: false,
2005                    pure: false,
2006                    isSleeping: false,
2007                    readFunction: options["read"],
2008                    evaluatorFunctionTarget: evaluatorFunctionTarget || options["owner"],
2009                    disposeWhenNodeIsRemoved: options["disposeWhenNodeIsRemoved"] || options.disposeWhenNodeIsRemoved || null,
2010                    disposeWhen: options["disposeWhen"] || options.disposeWhen,
2011                    domNodeDisposalCallback: null,
2012                    dependencyTracking: {},
2013                    dependenciesCount: 0,
2014                    evaluationTimeoutInstance: null
2015                };
2016
2017                function computedObservable() {
2018                    if (arguments.length > 0) {
2019                        if (typeof writeFunction === "function") {
2020                            // Writing a value
2021                            writeFunction.apply(state.evaluatorFunctionTarget, arguments);
2022                        } else {
2023                            throw new Error("Cannot write a value to a ko.computed unless you specify a 'write' option. If you wish to read the current value, don't pass any parameters.");
2024                        }
2025                        return this; // Permits chained assignments
2026                    } else {
2027                        // Reading the value
2028                        if (!state.isDisposed) {
2029                            ko.dependencyDetection.registerDependency(computedObservable);
2030                        }
2031                        if (state.isDirty || (state.isSleeping && computedObservable.haveDependenciesChanged())) {
2032                            computedObservable.evaluateImmediate();
2033                        }
2034                        return state.latestValue;
2035                    }
2036                }
2037
2038                computedObservable[computedState] = state;
2039                computedObservable.hasWriteFunction = typeof writeFunction === "function";
2040
2041                // Inherit from 'subscribable'
2042                if (!ko.utils.canSetPrototype) {
2043                    // 'subscribable' won't be on the prototype chain unless we put it there directly
2044                    ko.utils.extend(computedObservable, ko.subscribable['fn']);
2045                }
2046                ko.subscribable['fn'].init(computedObservable);
2047
2048                // Inherit from 'computed'
2049                ko.utils.setPrototypeOfOrExtend(computedObservable, computedFn);
2050
2051                if (options['pure']) {
2052                    state.pure = true;
2053                    state.isSleeping = true;     // Starts off sleeping; will awake on the first subscription
2054                    ko.utils.extend(computedObservable, pureComputedOverrides);
2055                } else if (options['deferEvaluation']) {
2056                    ko.utils.extend(computedObservable, deferEvaluationOverrides);
2057                }
2058
2059                if (ko.options['deferUpdates']) {
2060                    ko.extenders['deferred'](computedObservable, true);
2061                }
2062
2063                if (DEBUG) {
2064                    // #1731 - Aid debugging by exposing the computed's options
2065                    computedObservable["_options"] = options;
2066                }
2067
2068                if (state.disposeWhenNodeIsRemoved) {
2069                    // Since this computed is associated with a DOM node, and we don't want to dispose the computed
2070                    // until the DOM node is *removed* from the document (as opposed to never having been in the document),
2071                    // we'll prevent disposal until "disposeWhen" first returns false.
2072                    state.suppressDisposalUntilDisposeWhenReturnsFalse = true;
2073
2074                    // disposeWhenNodeIsRemoved: true can be used to opt into the "only dispose after first false result"
2075                    // behaviour even if there's no specific node to watch. In that case, clear the option so we don't try
2076                    // to watch for a non-node's disposal. This technique is intended for KO's internal use only and shouldn't
2077                    // be documented or used by application code, as it's likely to change in a future version of KO.
2078                    if (!state.disposeWhenNodeIsRemoved.nodeType) {
2079                        state.disposeWhenNodeIsRemoved = null;
2080                    }
2081                }
2082
2083                // Evaluate, unless sleeping or deferEvaluation is true
2084                if (!state.isSleeping && !options['deferEvaluation']) {
2085                    computedObservable.evaluateImmediate();
2086                }
2087
2088                // Attach a DOM node disposal callback so that the computed will be proactively disposed as soon as the node is
2089                // removed using ko.removeNode. But skip if isActive is false (there will never be any dependencies to dispose).
2090                if (state.disposeWhenNodeIsRemoved && computedObservable.isActive()) {
2091                    ko.utils.domNodeDisposal.addDisposeCallback(state.disposeWhenNodeIsRemoved, state.domNodeDisposalCallback = function () {
2092                        computedObservable.dispose();
2093                    });
2094                }
2095
2096                return computedObservable;
2097            };
2098
2099            // Utility function that disposes a given dependencyTracking entry
2100            function computedDisposeDependencyCallback(id, entryToDispose) {
2101                if (entryToDispose !== null && entryToDispose.dispose) {
2102                    entryToDispose.dispose();
2103                }
2104            }
2105
2106            // This function gets called each time a dependency is detected while evaluating a computed.
2107            // It's factored out as a shared function to avoid creating unnecessary function instances during evaluation.
2108            function computedBeginDependencyDetectionCallback(subscribable, id) {
2109                var computedObservable = this.computedObservable,
2110                    state = computedObservable[computedState];
2111                if (!state.isDisposed) {
2112                    if (this.disposalCount && this.disposalCandidates[id]) {
2113                        // Don't want to dispose this subscription, as it's still being used
2114                        computedObservable.addDependencyTracking(id, subscribable, this.disposalCandidates[id]);
2115                        this.disposalCandidates[id] = null; // No need to actually delete the property - disposalCandidates is a transient object anyway
2116                        --this.disposalCount;
2117                    } else if (!state.dependencyTracking[id]) {
2118                        // Brand new subscription - add it
2119                        computedObservable.addDependencyTracking(id, subscribable, state.isSleeping ? { _target: subscribable } : computedObservable.subscribeToDependency(subscribable));
2120                    }
2121                    // If the observable we've accessed has a pending notification, ensure we get notified of the actual final value (bypass equality checks)
2122                    if (subscribable._notificationIsPending) {
2123                        subscribable._notifyNextChangeIfValueIsDifferent();
2124                    }
2125                }
2126            }
2127
2128            var computedFn = {
2129                "equalityComparer": valuesArePrimitiveAndEqual,
2130                getDependenciesCount: function () {
2131                    return this[computedState].dependenciesCount;
2132                },
2133                getDependencies: function () {
2134                    var dependencyTracking = this[computedState].dependencyTracking, dependentObservables = [];
2135
2136                    ko.utils.objectForEach(dependencyTracking, function (id, dependency) {
2137                        dependentObservables[dependency._order] = dependency._target;
2138                    });
2139
2140                    return dependentObservables;
2141                },
2142                hasAncestorDependency: function (obs) {
2143                    if (!this[computedState].dependenciesCount) {
2144                        return false;
2145                    }
2146                    var dependencies = this.getDependencies();
2147                    if (ko.utils.arrayIndexOf(dependencies, obs) !== -1) {
2148                        return true;
2149                    }
2150                    return !!ko.utils.arrayFirst(dependencies, function (dep) {
2151                        return dep.hasAncestorDependency && dep.hasAncestorDependency(obs);
2152                    });
2153                },
2154                addDependencyTracking: function (id, target, trackingObj) {
2155                    if (this[computedState].pure && target === this) {
2156                        throw Error("A 'pure' computed must not be called recursively");
2157                    }
2158
2159                    this[computedState].dependencyTracking[id] = trackingObj;
2160                    trackingObj._order = this[computedState].dependenciesCount++;
2161                    trackingObj._version = target.getVersion();
2162                },
2163                haveDependenciesChanged: function () {
2164                    var id, dependency, dependencyTracking = this[computedState].dependencyTracking;
2165                    for (id in dependencyTracking) {
2166                        if (Object.prototype.hasOwnProperty.call(dependencyTracking, id)) {
2167                            dependency = dependencyTracking[id];
2168                            if ((this._evalDelayed && dependency._target._notificationIsPending) || dependency._target.hasChanged(dependency._version)) {
2169                                return true;
2170                            }
2171                        }
2172                    }
2173                },
2174                markDirty: function () {
2175                    // Process "dirty" events if we can handle delayed notifications
2176                    if (this._evalDelayed && !this[computedState].isBeingEvaluated) {
2177                        this._evalDelayed(false /*isChange*/);
2178                    }
2179                },
2180                isActive: function () {
2181                    var state = this[computedState];
2182                    return state.isDirty || state.dependenciesCount > 0;
2183                },
2184                respondToChange: function () {
2185                    // Ignore "change" events if we've already scheduled a delayed notification
2186                    if (!this._notificationIsPending) {
2187                        this.evaluatePossiblyAsync();
2188                    } else if (this[computedState].isDirty) {
2189                        this[computedState].isStale = true;
2190                    }
2191                },
2192                subscribeToDependency: function (target) {
2193                    if (target._deferUpdates) {
2194                        var dirtySub = target.subscribe(this.markDirty, this, 'dirty'),
2195                            changeSub = target.subscribe(this.respondToChange, this);
2196                        return {
2197                            _target: target,
2198                            dispose: function () {
2199                                dirtySub.dispose();
2200                                changeSub.dispose();
2201                            }
2202                        };
2203                    } else {
2204                        return target.subscribe(this.evaluatePossiblyAsync, this);
2205                    }
2206                },
2207                evaluatePossiblyAsync: function () {
2208                    var computedObservable = this,
2209                        throttleEvaluationTimeout = computedObservable['throttleEvaluation'];
2210                    if (throttleEvaluationTimeout && throttleEvaluationTimeout >= 0) {
2211                        clearTimeout(this[computedState].evaluationTimeoutInstance);
2212                        this[computedState].evaluationTimeoutInstance = ko.utils.setTimeout(function () {
2213                            computedObservable.evaluateImmediate(true /*notifyChange*/);
2214                        }, throttleEvaluationTimeout);
2215                    } else if (computedObservable._evalDelayed) {
2216                        computedObservable._evalDelayed(true /*isChange*/);
2217                    } else {
2218                        computedObservable.evaluateImmediate(true /*notifyChange*/);
2219                    }
2220                },
2221                evaluateImmediate: function (notifyChange) {
2222                    var computedObservable = this,
2223                        state = computedObservable[computedState],
2224                        disposeWhen = state.disposeWhen,
2225                        changed = false;
2226
2227                    if (state.isBeingEvaluated) {
2228                        // If the evaluation of a ko.computed causes side effects, it's possible that it will trigger its own re-evaluation.
2229                        // This is not desirable (it's hard for a developer to realise a chain of dependencies might cause this, and they almost
2230                        // certainly didn't intend infinite re-evaluations). So, for predictability, we simply prevent ko.computeds from causing
2231                        // their own re-evaluation. Further discussion at https://github.com/SteveSanderson/knockout/pull/387
2232                        return;
2233                    }
2234
2235                    // Do not evaluate (and possibly capture new dependencies) if disposed
2236                    if (state.isDisposed) {
2237                        return;
2238                    }
2239
2240                    if (state.disposeWhenNodeIsRemoved && !ko.utils.domNodeIsAttachedToDocument(state.disposeWhenNodeIsRemoved) || disposeWhen && disposeWhen()) {
2241                        // See comment above about suppressDisposalUntilDisposeWhenReturnsFalse
2242                        if (!state.suppressDisposalUntilDisposeWhenReturnsFalse) {
2243                            computedObservable.dispose();
2244                            return;
2245                        }
2246                    } else {
2247                        // It just did return false, so we can stop suppressing now
2248                        state.suppressDisposalUntilDisposeWhenReturnsFalse = false;
2249                    }
2250
2251                    state.isBeingEvaluated = true;
2252                    try {
2253                        changed = this.evaluateImmediate_CallReadWithDependencyDetection(notifyChange);
2254                    } finally {
2255                        state.isBeingEvaluated = false;
2256                    }
2257
2258                    return changed;
2259                },
2260                evaluateImmediate_CallReadWithDependencyDetection: function (notifyChange) {
2261                    // This function is really just part of the evaluateImmediate logic. You would never call it from anywhere else.
2262                    // Factoring it out into a separate function means it can be independent of the try/catch block in evaluateImmediate,
2263                    // which contributes to saving about 40% off the CPU overhead of computed evaluation (on V8 at least).
2264
2265                    var computedObservable = this,
2266                        state = computedObservable[computedState],
2267                        changed = false;
2268
2269                    // Initially, we assume that none of the subscriptions are still being used (i.e., all are candidates for disposal).
2270                    // Then, during evaluation, we cross off any that are in fact still being used.
2271                    var isInitial = state.pure ? undefined : !state.dependenciesCount,   // If we're evaluating when there are no previous dependencies, it must be the first time
2272                        dependencyDetectionContext = {
2273                            computedObservable: computedObservable,
2274                            disposalCandidates: state.dependencyTracking,
2275                            disposalCount: state.dependenciesCount
2276                        };
2277
2278                    ko.dependencyDetection.begin({
2279                        callbackTarget: dependencyDetectionContext,
2280                        callback: computedBeginDependencyDetectionCallback,
2281                        computed: computedObservable,
2282                        isInitial: isInitial
2283                    });
2284
2285                    state.dependencyTracking = {};
2286                    state.dependenciesCount = 0;
2287
2288                    var newValue = this.evaluateImmediate_CallReadThenEndDependencyDetection(state, dependencyDetectionContext);
2289
2290                    if (!state.dependenciesCount) {
2291                        computedObservable.dispose();
2292                        changed = true; // When evaluation causes a disposal, make sure all dependent computeds get notified so they'll see the new state
2293                    } else {
2294                        changed = computedObservable.isDifferent(state.latestValue, newValue);
2295                    }
2296
2297                    if (changed) {
2298                        if (!state.isSleeping) {
2299                            computedObservable["notifySubscribers"](state.latestValue, "beforeChange");
2300                        } else {
2301                            computedObservable.updateVersion();
2302                        }
2303
2304                        state.latestValue = newValue;
2305                        if (DEBUG) computedObservable._latestValue = newValue;
2306
2307                        computedObservable["notifySubscribers"](state.latestValue, "spectate");
2308
2309                        if (!state.isSleeping && notifyChange) {
2310                            computedObservable["notifySubscribers"](state.latestValue);
2311                        }
2312                        if (computedObservable._recordUpdate) {
2313                            computedObservable._recordUpdate();
2314                        }
2315                    }
2316
2317                    if (isInitial) {
2318                        computedObservable["notifySubscribers"](state.latestValue, "awake");
2319                    }
2320
2321                    return changed;
2322                },
2323                evaluateImmediate_CallReadThenEndDependencyDetection: function (state, dependencyDetectionContext) {
2324                    // This function is really part of the evaluateImmediate_CallReadWithDependencyDetection logic.
2325                    // You'd never call it from anywhere else. Factoring it out means that evaluateImmediate_CallReadWithDependencyDetection
2326                    // can be independent of try/finally blocks, which contributes to saving about 40% off the CPU
2327                    // overhead of computed evaluation (on V8 at least).
2328
2329                    try {
2330                        var readFunction = state.readFunction;
2331                        return state.evaluatorFunctionTarget ? readFunction.call(state.evaluatorFunctionTarget) : readFunction();
2332                    } finally {
2333                        ko.dependencyDetection.end();
2334
2335                        // For each subscription no longer being used, remove it from the active subscriptions list and dispose it
2336                        if (dependencyDetectionContext.disposalCount && !state.isSleeping) {
2337                            ko.utils.objectForEach(dependencyDetectionContext.disposalCandidates, computedDisposeDependencyCallback);
2338                        }
2339
2340                        state.isStale = state.isDirty = false;
2341                    }
2342                },
2343                peek: function (evaluate) {
2344                    // By default, peek won't re-evaluate, except while the computed is sleeping or to get the initial value when "deferEvaluation" is set.
2345                    // Pass in true to evaluate if needed.
2346                    var state = this[computedState];
2347                    if ((state.isDirty && (evaluate || !state.dependenciesCount)) || (state.isSleeping && this.haveDependenciesChanged())) {
2348                        this.evaluateImmediate();
2349                    }
2350                    return state.latestValue;
2351                },
2352                limit: function (limitFunction) {
2353                    // Override the limit function with one that delays evaluation as well
2354                    ko.subscribable['fn'].limit.call(this, limitFunction);
2355                    this._evalIfChanged = function () {
2356                        if (!this[computedState].isSleeping) {
2357                            if (this[computedState].isStale) {
2358                                this.evaluateImmediate();
2359                            } else {
2360                                this[computedState].isDirty = false;
2361                            }
2362                        }
2363                        return this[computedState].latestValue;
2364                    };
2365                    this._evalDelayed = function (isChange) {
2366                        this._limitBeforeChange(this[computedState].latestValue);
2367
2368                        // Mark as dirty
2369                        this[computedState].isDirty = true;
2370                        if (isChange) {
2371                            this[computedState].isStale = true;
2372                        }
2373
2374                        // Pass the observable to the "limit" code, which will evaluate it when
2375                        // it's time to do the notification.
2376                        this._limitChange(this, !isChange /* isDirty */);
2377                    };
2378                },
2379                dispose: function () {
2380                    var state = this[computedState];
2381                    if (!state.isSleeping && state.dependencyTracking) {
2382                        ko.utils.objectForEach(state.dependencyTracking, function (id, dependency) {
2383                            if (dependency.dispose)
2384                                dependency.dispose();
2385                        });
2386                    }
2387                    if (state.disposeWhenNodeIsRemoved && state.domNodeDisposalCallback) {
2388                        ko.utils.domNodeDisposal.removeDisposeCallback(state.disposeWhenNodeIsRemoved, state.domNodeDisposalCallback);
2389                    }
2390                    state.dependencyTracking = undefined;
2391                    state.dependenciesCount = 0;
2392                    state.isDisposed = true;
2393                    state.isStale = false;
2394                    state.isDirty = false;
2395                    state.isSleeping = false;
2396                    state.disposeWhenNodeIsRemoved = undefined;
2397                    state.disposeWhen = undefined;
2398                    state.readFunction = undefined;
2399                    if (!this.hasWriteFunction) {
2400                        state.evaluatorFunctionTarget = undefined;
2401                    }
2402                }
2403            };
2404
2405            var pureComputedOverrides = {
2406                beforeSubscriptionAdd: function (event) {
2407                    // If asleep, wake up the computed by subscribing to any dependencies.
2408                    var computedObservable = this,
2409                        state = computedObservable[computedState];
2410                    if (!state.isDisposed && state.isSleeping && event == 'change') {
2411                        state.isSleeping = false;
2412                        if (state.isStale || computedObservable.haveDependenciesChanged()) {
2413                            state.dependencyTracking = null;
2414                            state.dependenciesCount = 0;
2415                            if (computedObservable.evaluateImmediate()) {
2416                                computedObservable.updateVersion();
2417                            }
2418                        } else {
2419                            // First put the dependencies in order
2420                            var dependenciesOrder = [];
2421                            ko.utils.objectForEach(state.dependencyTracking, function (id, dependency) {
2422                                dependenciesOrder[dependency._order] = id;
2423                            });
2424                            // Next, subscribe to each one
2425                            ko.utils.arrayForEach(dependenciesOrder, function (id, order) {
2426                                var dependency = state.dependencyTracking[id],
2427                                    subscription = computedObservable.subscribeToDependency(dependency._target);
2428                                subscription._order = order;
2429                                subscription._version = dependency._version;
2430                                state.dependencyTracking[id] = subscription;
2431                            });
2432                            // Waking dependencies may have triggered effects
2433                            if (computedObservable.haveDependenciesChanged()) {
2434                                if (computedObservable.evaluateImmediate()) {
2435                                    computedObservable.updateVersion();
2436                                }
2437                            }
2438                        }
2439
2440                        if (!state.isDisposed) {     // test since evaluating could trigger disposal
2441                            computedObservable["notifySubscribers"](state.latestValue, "awake");
2442                        }
2443                    }
2444                },
2445                afterSubscriptionRemove: function (event) {
2446                    var state = this[computedState];
2447                    if (!state.isDisposed && event == 'change' && !this.hasSubscriptionsForEvent('change')) {
2448                        ko.utils.objectForEach(state.dependencyTracking, function (id, dependency) {
2449                            if (dependency.dispose) {
2450                                state.dependencyTracking[id] = {
2451                                    _target: dependency._target,
2452                                    _order: dependency._order,
2453                                    _version: dependency._version
2454                                };
2455                                dependency.dispose();
2456                            }
2457                        });
2458                        state.isSleeping = true;
2459                        this["notifySubscribers"](undefined, "asleep");
2460                    }
2461                },
2462                getVersion: function () {
2463                    // Because a pure computed is not automatically updated while it is sleeping, we can't
2464                    // simply return the version number. Instead, we check if any of the dependencies have
2465                    // changed and conditionally re-evaluate the computed observable.
2466                    var state = this[computedState];
2467                    if (state.isSleeping && (state.isStale || this.haveDependenciesChanged())) {
2468                        this.evaluateImmediate();
2469                    }
2470                    return ko.subscribable['fn'].getVersion.call(this);
2471                }
2472            };
2473
2474            var deferEvaluationOverrides = {
2475                beforeSubscriptionAdd: function (event) {
2476                    // This will force a computed with deferEvaluation to evaluate when the first subscription is registered.
2477                    if (event == 'change' || event == 'beforeChange') {
2478                        this.peek();
2479                    }
2480                }
2481            };
2482
2483            // Note that for browsers that don't support proto assignment, the
2484            // inheritance chain is created manually in the ko.computed constructor
2485            if (ko.utils.canSetPrototype) {
2486                ko.utils.setPrototypeOf(computedFn, ko.subscribable['fn']);
2487            }
2488
2489            // Set the proto values for ko.computed
2490            var protoProp = ko.observable.protoProperty; // == "__ko_proto__"
2491            computedFn[protoProp] = ko.computed;
2492
2493            ko.isComputed = function (instance) {
2494                return (typeof instance == 'function' && instance[protoProp] === computedFn[protoProp]);
2495            };
2496
2497            ko.isPureComputed = function (instance) {
2498                return ko.isComputed(instance) && instance[computedState] && instance[computedState].pure;
2499            };
2500
2501            ko.exportSymbol('computed', ko.computed);
2502            ko.exportSymbol('dependentObservable', ko.computed);    // export ko.dependentObservable for backwards compatibility (1.x)
2503            ko.exportSymbol('isComputed', ko.isComputed);
2504            ko.exportSymbol('isPureComputed', ko.isPureComputed);
2505            ko.exportSymbol('computed.fn', computedFn);
2506            ko.exportProperty(computedFn, 'peek', computedFn.peek);
2507            ko.exportProperty(computedFn, 'dispose', computedFn.dispose);
2508            ko.exportProperty(computedFn, 'isActive', computedFn.isActive);
2509            ko.exportProperty(computedFn, 'getDependenciesCount', computedFn.getDependenciesCount);
2510            ko.exportProperty(computedFn, 'getDependencies', computedFn.getDependencies);
2511
2512            ko.pureComputed = function (evaluatorFunctionOrOptions, evaluatorFunctionTarget) {
2513                if (typeof evaluatorFunctionOrOptions === 'function') {
2514                    return ko.computed(evaluatorFunctionOrOptions, evaluatorFunctionTarget, { 'pure': true });
2515                } else {
2516                    evaluatorFunctionOrOptions = ko.utils.extend({}, evaluatorFunctionOrOptions);   // make a copy of the parameter object
2517                    evaluatorFunctionOrOptions['pure'] = true;
2518                    return ko.computed(evaluatorFunctionOrOptions, evaluatorFunctionTarget);
2519                }
2520            }
2521            ko.exportSymbol('pureComputed', ko.pureComputed);
2522
2523            (function () {
2524                var maxNestedObservableDepth = 10; // Escape the (unlikely) pathological case where an observable's current value is itself (or similar reference cycle)
2525
2526                ko.toJS = function (rootObject) {
2527                    if (arguments.length == 0)
2528                        throw new Error("When calling ko.toJS, pass the object you want to convert.");
2529
2530                    // We just unwrap everything at every level in the object graph
2531                    return mapJsObjectGraph(rootObject, function (valueToMap) {
2532                        // Loop because an observable's value might in turn be another observable wrapper
2533                        for (var i = 0; ko.isObservable(valueToMap) && (i < maxNestedObservableDepth); i++)
2534                            valueToMap = valueToMap();
2535                        return valueToMap;
2536                    });
2537                };
2538
2539                ko.toJSON = function (rootObject, replacer, space) {     // replacer and space are optional
2540                    var plainJavaScriptObject = ko.toJS(rootObject);
2541                    return ko.utils.stringifyJson(plainJavaScriptObject, replacer, space);
2542                };
2543
2544                function mapJsObjectGraph(rootObject, mapInputCallback, visitedObjects) {
2545                    visitedObjects = visitedObjects || new objectLookup();
2546
2547                    rootObject = mapInputCallback(rootObject);
2548                    var canHaveProperties = (typeof rootObject == "object") && (rootObject !== null) && (rootObject !== undefined) && (!(rootObject instanceof RegExp)) && (!(rootObject instanceof Date)) && (!(rootObject instanceof String)) && (!(rootObject instanceof Number)) && (!(rootObject instanceof Boolean));
2549                    if (!canHaveProperties)
2550                        return rootObject;
2551
2552                    var outputProperties = rootObject instanceof Array ? [] : {};
2553                    visitedObjects.save(rootObject, outputProperties);
2554
2555                    visitPropertiesOrArrayEntries(rootObject, function (indexer) {
2556                        var propertyValue = mapInputCallback(rootObject[indexer]);
2557
2558                        switch (typeof propertyValue) {
2559                            case "boolean":
2560                            case "number":
2561                            case "string":
2562                            case "function":
2563                                outputProperties[indexer] = propertyValue;
2564                                break;
2565                            case "object":
2566                            case "undefined":
2567                                var previouslyMappedValue = visitedObjects.get(propertyValue);
2568                                outputProperties[indexer] = (previouslyMappedValue !== undefined)
2569                                    ? previouslyMappedValue
2570                                    : mapJsObjectGraph(propertyValue, mapInputCallback, visitedObjects);
2571                                break;
2572                        }
2573                    });
2574
2575                    return outputProperties;
2576                }
2577
2578                function visitPropertiesOrArrayEntries(rootObject, visitorCallback) {
2579                    if (rootObject instanceof Array) {
2580                        for (var i = 0; i < rootObject.length; i++)
2581                            visitorCallback(i);
2582
2583                        // For arrays, also respect toJSON property for custom mappings (fixes #278)
2584                        if (typeof rootObject['toJSON'] == 'function')
2585                            visitorCallback('toJSON');
2586                    } else {
2587                        for (var propertyName in rootObject) {
2588                            visitorCallback(propertyName);
2589                        }
2590                    }
2591                };
2592
2593                function objectLookup() {
2594                    this.keys = [];
2595                    this.values = [];
2596                };
2597
2598                objectLookup.prototype = {
2599                    constructor: objectLookup,
2600                    save: function (key, value) {
2601                        var existingIndex = ko.utils.arrayIndexOf(this.keys, key);
2602                        if (existingIndex >= 0)
2603                            this.values[existingIndex] = value;
2604                        else {
2605                            this.keys.push(key);
2606                            this.values.push(value);
2607                        }
2608                    },
2609                    get: function (key) {
2610                        var existingIndex = ko.utils.arrayIndexOf(this.keys, key);
2611                        return (existingIndex >= 0) ? this.values[existingIndex] : undefined;
2612                    }
2613                };
2614            })();
2615
2616            ko.exportSymbol('toJS', ko.toJS);
2617            ko.exportSymbol('toJSON', ko.toJSON);
2618            ko.when = function (predicate, callback, context) {
2619                function kowhen(resolve) {
2620                    var observable = ko.pureComputed(predicate, context).extend({ notify: 'always' });
2621                    var subscription = observable.subscribe(function (value) {
2622                        if (value) {
2623                            subscription.dispose();
2624                            resolve(value);
2625                        }
2626                    });
2627                    // In case the initial value is true, process it right away
2628                    observable['notifySubscribers'](observable.peek());
2629
2630                    return subscription;
2631                }
2632                if (typeof Promise === "function" && !callback) {
2633                    return new Promise(kowhen);
2634                } else {
2635                    return kowhen(callback.bind(context));
2636                }
2637            };
2638
2639            ko.exportSymbol('when', ko.when);
2640            (function () {
2641                var hasDomDataExpandoProperty = '__ko__hasDomDataOptionValue__';
2642
2643                // Normally, SELECT elements and their OPTIONs can only take value of type 'string' (because the values
2644                // are stored on DOM attributes). ko.selectExtensions provides a way for SELECTs/OPTIONs to have values
2645                // that are arbitrary objects. This is very convenient when implementing things like cascading dropdowns.
2646                ko.selectExtensions = {
2647                    readValue: function (element) {
2648                        switch (ko.utils.tagNameLower(element)) {
2649                            case 'option':
2650                                if (element[hasDomDataExpandoProperty] === true)
2651                                    return ko.utils.domData.get(element, ko.bindingHandlers.options.optionValueDomDataKey);
2652                                return ko.utils.ieVersion <= 7
2653                                    ? (element.getAttributeNode('value') && element.getAttributeNode('value').specified ? element.value : element.text)
2654                                    : element.value;
2655                            case 'select':
2656                                return element.selectedIndex >= 0 ? ko.selectExtensions.readValue(element.options[element.selectedIndex]) : undefined;
2657                            default:
2658                                return element.value;
2659                        }
2660                    },
2661
2662                    writeValue: function (element, value, allowUnset) {
2663                        switch (ko.utils.tagNameLower(element)) {
2664                            case 'option':
2665                                if (typeof value === "string") {
2666                                    ko.utils.domData.set(element, ko.bindingHandlers.options.optionValueDomDataKey, undefined);
2667                                    if (hasDomDataExpandoProperty in element) { // IE <= 8 throws errors if you delete non-existent properties from a DOM node
2668                                        delete element[hasDomDataExpandoProperty];
2669                                    }
2670                                    element.value = value;
2671                                }
2672                                else {
2673                                    // Store arbitrary object using DomData
2674                                    ko.utils.domData.set(element, ko.bindingHandlers.options.optionValueDomDataKey, value);
2675                                    element[hasDomDataExpandoProperty] = true;
2676
2677                                    // Special treatment of numbers is just for backward compatibility. KO 1.2.1 wrote numerical values to element.value.
2678                                    element.value = typeof value === "number" ? value : "";
2679                                }
2680                                break;
2681                            case 'select':
2682                                if (value === "" || value === null)       // A blank string or null value will select the caption
2683                                    value = undefined;
2684                                var selection = -1;
2685                                for (var i = 0, n = element.options.length, optionValue; i < n; ++i) {
2686                                    optionValue = ko.selectExtensions.readValue(element.options[i]);
2687                                    // Include special check to handle selecting a caption with a blank string value
2688                                    if (optionValue == value || (optionValue === "" && value === undefined)) {
2689                                        selection = i;
2690                                        break;
2691                                    }
2692                                }
2693                                if (allowUnset || selection >= 0 || (value === undefined && element.size > 1)) {
2694                                    element.selectedIndex = selection;
2695                                    if (ko.utils.ieVersion === 6) {
2696                                        // Workaround for IE6 bug: It won't reliably apply values to SELECT nodes during the same execution thread
2697                                        // right after you've changed the set of OPTION nodes on it. So for that node type, we'll schedule a second thread
2698                                        // to apply the value as well.
2699                                        ko.utils.setTimeout(function () {
2700                                            element.selectedIndex = selection;
2701                                        }, 0);
2702                                    }
2703                                }
2704                                break;
2705                            default:
2706                                if ((value === null) || (value === undefined))
2707                                    value = "";
2708                                element.value = value;
2709                                break;
2710                        }
2711                    }
2712                };
2713            })();
2714
2715            ko.exportSymbol('selectExtensions', ko.selectExtensions);
2716            ko.exportSymbol('selectExtensions.readValue', ko.selectExtensions.readValue);
2717            ko.exportSymbol('selectExtensions.writeValue', ko.selectExtensions.writeValue);
2718            ko.expressionRewriting = (function () {
2719                var javaScriptReservedWords = ["true", "false", "null", "undefined"];
2720
2721                // Matches something that can be assigned to--either an isolated identifier or something ending with a property accessor
2722                // This is designed to be simple and avoid false negatives, but could produce false positives (e.g., a+b.c).
2723                // This also will not properly handle nested brackets (e.g., obj1[obj2['prop']]; see #911).
2724                var javaScriptAssignmentTarget = /^(?:[$_a-z][$\w]*|(.+)(\.\s*[$_a-z][$\w]*|\[.+\]))$/i;
2725
2726                function getWriteableValue(expression) {
2727                    if (ko.utils.arrayIndexOf(javaScriptReservedWords, expression) >= 0)
2728                        return false;
2729                    var match = expression.match(javaScriptAssignmentTarget);
2730                    return match === null ? false : match[1] ? ('Object(' + match[1] + ')' + match[2]) : expression;
2731                }
2732
2733                // The following regular expressions will be used to split an object-literal string into tokens
2734
2735                var specials = ',"\'`{}()/:[\\]',    // These characters have special meaning to the parser and must not appear in the middle of a token, except as part of a string.
2736                    // Create the actual regular expression by or-ing the following regex strings. The order is important.
2737                    bindingToken = RegExp([
2738                        // These match strings, either with double quotes, single quotes, or backticks
2739                        '"(?:\\\\.|[^"])*"',
2740                        "'(?:\\\\.|[^'])*'",
2741                        "`(?:\\\\.|[^`])*`",
2742                        // Match C style comments
2743                        "/\\*(?:[^*]|\\*+[^*/])*\\*+/",
2744                        // Match C++ style comments
2745                        "//.*\n",
2746                        // Match a regular expression (text enclosed by slashes), but will also match sets of divisions
2747                        // as a regular expression (this is handled by the parsing loop below).
2748                        '/(?:\\\\.|[^/])+/\w*',
2749                        // Match text (at least two characters) that does not contain any of the above special characters,
2750                        // although some of the special characters are allowed to start it (all but the colon and comma).
2751                        // The text can contain spaces, but leading or trailing spaces are skipped.
2752                        '[^\\s:,/][^' + specials + ']*[^\\s' + specials + ']',
2753                        // Match any non-space character not matched already. This will match colons and commas, since they're
2754                        // not matched by "everyThingElse", but will also match any other single character that wasn't already
2755                        // matched (for example: in "a: 1, b: 2", each of the non-space characters will be matched by oneNotSpace).
2756                        '[^\\s]'
2757                    ].join('|'), 'g'),
2758
2759                    // Match end of previous token to determine whether a slash is a division or regex.
2760                    divisionLookBehind = /[\])"'A-Za-z0-9_$]+$/,
2761                    keywordRegexLookBehind = { 'in': 1, 'return': 1, 'typeof': 1 };
2762
2763                function parseObjectLiteral(objectLiteralString) {
2764                    // Trim leading and trailing spaces from the string
2765                    var str = ko.utils.stringTrim(objectLiteralString);
2766
2767                    // Trim braces '{' surrounding the whole object literal
2768                    if (str.charCodeAt(0) === 123) str = str.slice(1, -1);
2769
2770                    // Add a newline to correctly match a C++ style comment at the end of the string and
2771                    // add a comma so that we don't need a separate code block to deal with the last item
2772                    str += "\n,";
2773
2774                    // Split into tokens
2775                    var result = [], toks = str.match(bindingToken), key, values = [], depth = 0;
2776
2777                    if (toks.length > 1) {
2778                        for (var i = 0, tok; tok = toks[i]; ++i) {
2779                            var c = tok.charCodeAt(0);
2780                            // A comma signals the end of a key/value pair if depth is zero
2781                            if (c === 44) { // ","
2782                                if (depth <= 0) {
2783                                    result.push((key && values.length) ? { key: key, value: values.join('') } : { 'unknown': key || values.join('') });
2784                                    key = depth = 0;
2785                                    values = [];
2786                                    continue;
2787                                }
2788                                // Simply skip the colon that separates the name and value
2789                            } else if (c === 58) { // ":"
2790                                if (!depth && !key && values.length === 1) {
2791                                    key = values.pop();
2792                                    continue;
2793                                }
2794                                // Comments: skip them
2795                            } else if (c === 47 && tok.length > 1 && (tok.charCodeAt(1) === 47 || tok.charCodeAt(1) === 42)) {  // "//" or "/*"
2796                                continue;
2797                                // A set of slashes is initially matched as a regular expression, but could be division
2798                            } else if (c === 47 && i && tok.length > 1) {  // "/"
2799                                // Look at the end of the previous token to determine if the slash is actually division
2800                                var match = toks[i - 1].match(divisionLookBehind);
2801                                if (match && !keywordRegexLookBehind[match[0]]) {
2802                                    // The slash is actually a division punctuator; re-parse the remainder of the string (not including the slash)
2803                                    str = str.substr(str.indexOf(tok) + 1);
2804                                    toks = str.match(bindingToken);
2805                                    i = -1;
2806                                    // Continue with just the slash
2807                                    tok = '/';
2808                                }
2809                                // Increment depth for parentheses, braces, and brackets so that interior commas are ignored
2810                            } else if (c === 40 || c === 123 || c === 91) { // '(', '{', '['
2811                                ++depth;
2812                            } else if (c === 41 || c === 125 || c === 93) { // ')', '}', ']'
2813                                --depth;
2814                                // The key will be the first token; if it's a string, trim the quotes
2815                            } else if (!key && !values.length && (c === 34 || c === 39)) { // '"', "'"
2816                                tok = tok.slice(1, -1);
2817                            }
2818                            values.push(tok);
2819                        }
2820                        if (depth > 0) {
2821                            throw Error("Unbalanced parentheses, braces, or brackets");
2822                        }
2823                    }
2824                    return result;
2825                }
2826
2827                // Two-way bindings include a write function that allow the handler to update the value even if it's not an observable.
2828                var twoWayBindings = {};
2829
2830                function preProcessBindings(bindingsStringOrKeyValueArray, bindingOptions) {
2831                    bindingOptions = bindingOptions || {};
2832
2833                    function processKeyValue(key, val) {
2834                        var writableVal;
2835                        function callPreprocessHook(obj) {
2836                            return (obj && obj['preprocess']) ? (val = obj['preprocess'](val, key, processKeyValue)) : true;
2837                        }
2838                        if (!bindingParams) {
2839                            if (!callPreprocessHook(ko['getBindingHandler'](key)))
2840                                return;
2841
2842                            if (twoWayBindings[key] && (writableVal = getWriteableValue(val))) {
2843                                // For two-way bindings, provide a write method in case the value
2844                                // isn't a writable observable.
2845                                var writeKey = typeof twoWayBindings[key] == 'string' ? twoWayBindings[key] : key;
2846                                propertyAccessorResultStrings.push("'" + writeKey + "':function(_z){" + writableVal + "=_z}");
2847                            }
2848                        }
2849                        // Values are wrapped in a function so that each value can be accessed independently
2850                        if (makeValueAccessors) {
2851                            val = 'function(){return ' + val + ' }';
2852                        }
2853                        resultStrings.push("'" + key + "':" + val);
2854                    }
2855
2856                    var resultStrings = [],
2857                        propertyAccessorResultStrings = [],
2858                        makeValueAccessors = bindingOptions['valueAccessors'],
2859                        bindingParams = bindingOptions['bindingParams'],
2860                        keyValueArray = typeof bindingsStringOrKeyValueArray === "string" ?
2861                            parseObjectLiteral(bindingsStringOrKeyValueArray) : bindingsStringOrKeyValueArray;
2862
2863                    ko.utils.arrayForEach(keyValueArray, function (keyValue) {
2864                        processKeyValue(keyValue.key || keyValue['unknown'], keyValue.value);
2865                    });
2866
2867                    if (propertyAccessorResultStrings.length)
2868                        processKeyValue('_ko_property_writers', "{" + propertyAccessorResultStrings.join(",") + " }");
2869
2870                    return resultStrings.join(",");
2871                }
2872
2873                return {
2874                    bindingRewriteValidators: [],
2875
2876                    twoWayBindings: twoWayBindings,
2877
2878                    parseObjectLiteral: parseObjectLiteral,
2879
2880                    preProcessBindings: preProcessBindings,
2881
2882                    keyValueArrayContainsKey: function (keyValueArray, key) {
2883                        for (var i = 0; i < keyValueArray.length; i++)
2884                            if (keyValueArray[i]['key'] == key)
2885                                return true;
2886                        return false;
2887                    },
2888
2889                    // Internal, private KO utility for updating model properties from within bindings
2890                    // property:            If the property being updated is (or might be) an observable, pass it here
2891                    //                      If it turns out to be a writable observable, it will be written to directly
2892                    // allBindings:         An object with a get method to retrieve bindings in the current execution context.
2893                    //                      This will be searched for a '_ko_property_writers' property in case you're writing to a non-observable
2894                    // key:                 The key identifying the property to be written. Example: for { hasFocus: myValue }, write to 'myValue' by specifying the key 'hasFocus'
2895                    // value:               The value to be written
2896                    // checkIfDifferent:    If true, and if the property being written is a writable observable, the value will only be written if
2897                    //                      it is !== existing value on that writable observable
2898                    writeValueToProperty: function (property, allBindings, key, value, checkIfDifferent) {
2899                        if (!property || !ko.isObservable(property)) {
2900                            var propWriters = allBindings.get('_ko_property_writers');
2901                            if (propWriters && propWriters[key])
2902                                propWriters[key](value);
2903                        } else if (ko.isWriteableObservable(property) && (!checkIfDifferent || property.peek() !== value)) {
2904                            property(value);
2905                        }
2906                    }
2907                };
2908            })();
2909
2910            ko.exportSymbol('expressionRewriting', ko.expressionRewriting);
2911            ko.exportSymbol('expressionRewriting.bindingRewriteValidators', ko.expressionRewriting.bindingRewriteValidators);
2912            ko.exportSymbol('expressionRewriting.parseObjectLiteral', ko.expressionRewriting.parseObjectLiteral);
2913            ko.exportSymbol('expressionRewriting.preProcessBindings', ko.expressionRewriting.preProcessBindings);
2914
2915            // Making bindings explicitly declare themselves as "two way" isn't ideal in the long term (it would be better if
2916            // all bindings could use an official 'property writer' API without needing to declare that they might). However,
2917            // since this is not, and has never been, a public API (_ko_property_writers was never documented), it's acceptable
2918            // as an internal implementation detail in the short term.
2919            // For those developers who rely on _ko_property_writers in their custom bindings, we expose _twoWayBindings as an
2920            // undocumented feature that makes it relatively easy to upgrade to KO 3.0. However, this is still not an official
2921            // public API, and we reserve the right to remove it at any time if we create a real public property writers API.
2922            ko.exportSymbol('expressionRewriting._twoWayBindings', ko.expressionRewriting.twoWayBindings);
2923
2924            // For backward compatibility, define the following aliases. (Previously, these function names were misleading because
2925            // they referred to JSON specifically, even though they actually work with arbitrary JavaScript object literal expressions.)
2926            ko.exportSymbol('jsonExpressionRewriting', ko.expressionRewriting);
2927            ko.exportSymbol('jsonExpressionRewriting.insertPropertyAccessorsIntoJson', ko.expressionRewriting.preProcessBindings);
2928            (function () {
2929                // "Virtual elements" is an abstraction on top of the usual DOM API which understands the notion that comment nodes
2930                // may be used to represent hierarchy (in addition to the DOM's natural hierarchy).
2931                // If you call the DOM-manipulating functions on ko.virtualElements, you will be able to read and write the state
2932                // of that virtual hierarchy
2933                //
2934                // The point of all this is to support containerless templates (e.g., <!-- ko foreach:someCollection -->blah<!-- /ko -->)
2935                // without having to scatter special cases all over the binding and templating code.
2936
2937                // IE 9 cannot reliably read the "nodeValue" property of a comment node (see https://github.com/SteveSanderson/knockout/issues/186)
2938                // but it does give them a nonstandard alternative property called "text" that it can read reliably. Other browsers don't have that property.
2939                // So, use node.text where available, and node.nodeValue elsewhere
2940                var commentNodesHaveTextProperty = document && document.createComment("test").text === "<!--test-->";
2941
2942                var startCommentRegex = commentNodesHaveTextProperty ? /^<!--\s*ko(?:\s+([\s\S]+))?\s*-->$/ : /^\s*ko(?:\s+([\s\S]+))?\s*$/;
2943                var endCommentRegex = commentNodesHaveTextProperty ? /^<!--\s*\/ko\s*-->$/ : /^\s*\/ko\s*$/;
2944                var htmlTagsWithOptionallyClosingChildren = { 'ul': true, 'ol': true };
2945
2946                function isStartComment(node) {
2947                    return (node.nodeType == 8) && startCommentRegex.test(commentNodesHaveTextProperty ? node.text : node.nodeValue);
2948                }
2949
2950                function isEndComment(node) {
2951                    return (node.nodeType == 8) && endCommentRegex.test(commentNodesHaveTextProperty ? node.text : node.nodeValue);
2952                }
2953
2954                function isUnmatchedEndComment(node) {
2955                    return isEndComment(node) && !(ko.utils.domData.get(node, matchedEndCommentDataKey));
2956                }
2957
2958                var matchedEndCommentDataKey = "__ko_matchedEndComment__"
2959
2960                function getVirtualChildren(startComment, allowUnbalanced) {
2961                    var currentNode = startComment;
2962                    var depth = 1;
2963                    var children = [];
2964                    while (currentNode = currentNode.nextSibling) {
2965                        if (isEndComment(currentNode)) {
2966                            ko.utils.domData.set(currentNode, matchedEndCommentDataKey, true);
2967                            depth--;
2968                            if (depth === 0)
2969                                return children;
2970                        }
2971
2972                        children.push(currentNode);
2973
2974                        if (isStartComment(currentNode))
2975                            depth++;
2976                    }
2977                    if (!allowUnbalanced)
2978                        throw new Error("Cannot find closing comment tag to match: " + startComment.nodeValue);
2979                    return null;
2980                }
2981
2982                function getMatchingEndComment(startComment, allowUnbalanced) {
2983                    var allVirtualChildren = getVirtualChildren(startComment, allowUnbalanced);
2984                    if (allVirtualChildren) {
2985                        if (allVirtualChildren.length > 0)
2986                            return allVirtualChildren[allVirtualChildren.length - 1].nextSibling;
2987                        return startComment.nextSibling;
2988                    } else
2989                        return null; // Must have no matching end comment, and allowUnbalanced is true
2990                }
2991
2992                function getUnbalancedChildTags(node) {
2993                    // e.g., from <div>OK</div><!-- ko blah --><span>Another</span>, returns: <!-- ko blah --><span>Another</span>
2994                    //       from <div>OK</div><!-- /ko --><!-- /ko -->,             returns: <!-- /ko --><!-- /ko -->
2995                    var childNode = node.firstChild, captureRemaining = null;
2996                    if (childNode) {
2997                        do {
2998                            if (captureRemaining)                   // We already hit an unbalanced node and are now just scooping up all subsequent nodes
2999                                captureRemaining.push(childNode);
3000                            else if (isStartComment(childNode)) {
3001                                var matchingEndComment = getMatchingEndComment(childNode, /* allowUnbalanced: */ true);
3002                                if (matchingEndComment)             // It's a balanced tag, so skip immediately to the end of this virtual set
3003                                    childNode = matchingEndComment;
3004                                else
3005                                    captureRemaining = [childNode]; // It's unbalanced, so start capturing from this point
3006                            } else if (isEndComment(childNode)) {
3007                                captureRemaining = [childNode];     // It's unbalanced (if it wasn't, we'd have skipped over it already), so start capturing
3008                            }
3009                        } while (childNode = childNode.nextSibling);
3010                    }
3011                    return captureRemaining;
3012                }
3013
3014                ko.virtualElements = {
3015                    allowedBindings: {},
3016
3017                    childNodes: function (node) {
3018                        return isStartComment(node) ? getVirtualChildren(node) : node.childNodes;
3019                    },
3020
3021                    emptyNode: function (node) {
3022                        if (!isStartComment(node))
3023                            ko.utils.emptyDomNode(node);
3024                        else {
3025                            var virtualChildren = ko.virtualElements.childNodes(node);
3026                            for (var i = 0, j = virtualChildren.length; i < j; i++)
3027                                ko.removeNode(virtualChildren[i]);
3028                        }
3029                    },
3030
3031                    setDomNodeChildren: function (node, childNodes) {
3032                        if (!isStartComment(node))
3033                            ko.utils.setDomNodeChildren(node, childNodes);
3034                        else {
3035                            ko.virtualElements.emptyNode(node);
3036                            var endCommentNode = node.nextSibling; // Must be the next sibling, as we just emptied the children
3037                            for (var i = 0, j = childNodes.length; i < j; i++)
3038                                endCommentNode.parentNode.insertBefore(childNodes[i], endCommentNode);
3039                        }
3040                    },
3041
3042                    prepend: function (containerNode, nodeToPrepend) {
3043                        var insertBeforeNode;
3044
3045                        if (isStartComment(containerNode)) {
3046                            // Start comments must always have a parent and at least one following sibling (the end comment)
3047                            insertBeforeNode = containerNode.nextSibling;
3048                            containerNode = containerNode.parentNode;
3049                        } else {
3050                            insertBeforeNode = containerNode.firstChild;
3051                        }
3052
3053                        if (!insertBeforeNode) {
3054                            containerNode.appendChild(nodeToPrepend);
3055                        } else if (nodeToPrepend !== insertBeforeNode) {       // IE will sometimes crash if you try to insert a node before itself
3056                            containerNode.insertBefore(nodeToPrepend, insertBeforeNode);
3057                        }
3058                    },
3059
3060                    insertAfter: function (containerNode, nodeToInsert, insertAfterNode) {
3061                        if (!insertAfterNode) {
3062                            ko.virtualElements.prepend(containerNode, nodeToInsert);
3063                        } else {
3064                            // Children of start comments must always have a parent and at least one following sibling (the end comment)
3065                            var insertBeforeNode = insertAfterNode.nextSibling;
3066
3067                            if (isStartComment(containerNode)) {
3068                                containerNode = containerNode.parentNode;
3069                            }
3070
3071                            if (!insertBeforeNode) {
3072                                containerNode.appendChild(nodeToInsert);
3073                            } else if (nodeToInsert !== insertBeforeNode) {       // IE will sometimes crash if you try to insert a node before itself
3074                                containerNode.insertBefore(nodeToInsert, insertBeforeNode);
3075                            }
3076                        }
3077                    },
3078
3079                    firstChild: function (node) {
3080                        if (!isStartComment(node)) {
3081                            if (node.firstChild && isEndComment(node.firstChild)) {
3082                                throw new Error("Found invalid end comment, as the first child of " + node);
3083                            }
3084                            return node.firstChild;
3085                        } else if (!node.nextSibling || isEndComment(node.nextSibling)) {
3086                            return null;
3087                        } else {
3088                            return node.nextSibling;
3089                        }
3090                    },
3091
3092                    nextSibling: function (node) {
3093                        if (isStartComment(node)) {
3094                            node = getMatchingEndComment(node);
3095                        }
3096
3097                        if (node.nextSibling && isEndComment(node.nextSibling)) {
3098                            if (isUnmatchedEndComment(node.nextSibling)) {
3099                                throw Error("Found end comment without a matching opening comment, as child of " + node);
3100                            } else {
3101                                return null;
3102                            }
3103                        } else {
3104                            return node.nextSibling;
3105                        }
3106                    },
3107
3108                    hasBindingValue: isStartComment,
3109
3110                    virtualNodeBindingValue: function (node) {
3111                        var regexMatch = (commentNodesHaveTextProperty ? node.text : node.nodeValue).match(startCommentRegex);
3112                        return regexMatch ? regexMatch[1] : null;
3113                    },
3114
3115                    normaliseVirtualElementDomStructure: function (elementVerified) {
3116                        // Workaround for https://github.com/SteveSanderson/knockout/issues/155
3117                        // (IE <= 8 or IE 9 quirks mode parses your HTML weirdly, treating closing </li> tags as if they don't exist, thereby moving comment nodes
3118                        // that are direct descendants of <ul> into the preceding <li>)
3119                        if (!htmlTagsWithOptionallyClosingChildren[ko.utils.tagNameLower(elementVerified)])
3120                            return;
3121
3122                        // Scan immediate children to see if they contain unbalanced comment tags. If they do, those comment tags
3123                        // must be intended to appear *after* that child, so move them there.
3124                        var childNode = elementVerified.firstChild;
3125                        if (childNode) {
3126                            do {
3127                                if (childNode.nodeType === 1) {
3128                                    var unbalancedTags = getUnbalancedChildTags(childNode);
3129                                    if (unbalancedTags) {
3130                                        // Fix up the DOM by moving the unbalanced tags to where they most likely were intended to be placed - *after* the child
3131                                        var nodeToInsertBefore = childNode.nextSibling;
3132                                        for (var i = 0; i < unbalancedTags.length; i++) {
3133                                            if (nodeToInsertBefore)
3134                                                elementVerified.insertBefore(unbalancedTags[i], nodeToInsertBefore);
3135                                            else
3136                                                elementVerified.appendChild(unbalancedTags[i]);
3137                                        }
3138                                    }
3139                                }
3140                            } while (childNode = childNode.nextSibling);
3141                        }
3142                    }
3143                };
3144            })();
3145            ko.exportSymbol('virtualElements', ko.virtualElements);
3146            ko.exportSymbol('virtualElements.allowedBindings', ko.virtualElements.allowedBindings);
3147            ko.exportSymbol('virtualElements.emptyNode', ko.virtualElements.emptyNode);
3148            //ko.exportSymbol('virtualElements.firstChild', ko.virtualElements.firstChild);     // firstChild is not minified
3149            ko.exportSymbol('virtualElements.insertAfter', ko.virtualElements.insertAfter);
3150            //ko.exportSymbol('virtualElements.nextSibling', ko.virtualElements.nextSibling);   // nextSibling is not minified
3151            ko.exportSymbol('virtualElements.prepend', ko.virtualElements.prepend);
3152            ko.exportSymbol('virtualElements.setDomNodeChildren', ko.virtualElements.setDomNodeChildren);
3153            (function () {
3154                var defaultBindingAttributeName = "data-bind";
3155
3156                ko.bindingProvider = function () {
3157                    this.bindingCache = {};
3158                };
3159
3160                ko.utils.extend(ko.bindingProvider.prototype, {
3161                    'nodeHasBindings': function (node) {
3162                        switch (node.nodeType) {
3163                            case 1: // Element
3164                                return node.getAttribute(defaultBindingAttributeName) != null
3165                                    || ko.components['getComponentNameForNode'](node);
3166                            case 8: // Comment node
3167                                return ko.virtualElements.hasBindingValue(node);
3168                            default: return false;
3169                        }
3170                    },
3171
3172                    'getBindings': function (node, bindingContext) {
3173                        var bindingsString = this['getBindingsString'](node, bindingContext),
3174                            parsedBindings = bindingsString ? this['parseBindingsString'](bindingsString, bindingContext, node) : null;
3175                        return ko.components.addBindingsForCustomElement(parsedBindings, node, bindingContext, /* valueAccessors */ false);
3176                    },
3177
3178                    'getBindingAccessors': function (node, bindingContext) {
3179                        var bindingsString = this['getBindingsString'](node, bindingContext),
3180                            parsedBindings = bindingsString ? this['parseBindingsString'](bindingsString, bindingContext, node, { 'valueAccessors': true }) : null;
3181                        return ko.components.addBindingsForCustomElement(parsedBindings, node, bindingContext, /* valueAccessors */ true);
3182                    },
3183
3184                    // The following function is only used internally by this default provider.
3185                    // It's not part of the interface definition for a general binding provider.
3186                    'getBindingsString': function (node, bindingContext) {
3187                        switch (node.nodeType) {
3188                            case 1: return node.getAttribute(defaultBindingAttributeName);   // Element
3189                            case 8: return ko.virtualElements.virtualNodeBindingValue(node); // Comment node
3190                            default: return null;
3191                        }
3192                    },
3193
3194                    // The following function is only used internally by this default provider.
3195                    // It's not part of the interface definition for a general binding provider.
3196                    'parseBindingsString': function (bindingsString, bindingContext, node, options) {
3197                        try {
3198                            var bindingFunction = createBindingsStringEvaluatorViaCache(bindingsString, this.bindingCache, options);
3199                            return bindingFunction(bindingContext, node);
3200                        } catch (ex) {
3201                            ex.message = "Unable to parse bindings.\nBindings value: " + bindingsString + "\nMessage: " + ex.message;
3202                            throw ex;
3203                        }
3204                    }
3205                });
3206
3207                ko.bindingProvider['instance'] = new ko.bindingProvider();
3208
3209                function createBindingsStringEvaluatorViaCache(bindingsString, cache, options) {
3210                    var cacheKey = bindingsString + (options && options['valueAccessors'] || '');
3211                    return cache[cacheKey]
3212                        || (cache[cacheKey] = createBindingsStringEvaluator(bindingsString, options));
3213                }
3214
3215                function createBindingsStringEvaluator(bindingsString, options) {
3216                    // Build the source for a function that evaluates "expression"
3217                    // For each scope variable, add an extra level of "with" nesting
3218                    // Example result: with(sc1) { with(sc0) { return (expression) } }
3219                    var rewrittenBindings = ko.expressionRewriting.preProcessBindings(bindingsString, options),
3220                        functionBody = "with($context){with($data||{}){return{" + rewrittenBindings + "}}}";
3221                    return new Function("$context", "$element", functionBody);
3222                }
3223            })();
3224
3225            ko.exportSymbol('bindingProvider', ko.bindingProvider);
3226            (function () {
3227                // Hide or don't minify context properties, see https://github.com/knockout/knockout/issues/2294
3228                var contextSubscribable = ko.utils.createSymbolOrString('_subscribable');
3229                var contextAncestorBindingInfo = ko.utils.createSymbolOrString('_ancestorBindingInfo');
3230                var contextDataDependency = ko.utils.createSymbolOrString('_dataDependency');
3231
3232                ko.bindingHandlers = {};
3233
3234                // The following element types will not be recursed into during binding.
3235                var bindingDoesNotRecurseIntoElementTypes = {
3236                    // Don't want bindings that operate on text nodes to mutate <script> and <textarea> contents,
3237                    // because it's unexpected and a potential XSS issue.
3238                    // Also bindings should not operate on <template> elements since this breaks in Internet Explorer
3239                    // and because such elements' contents are always intended to be bound in a different context
3240                    // from where they appear in the document.
3241                    'script': true,
3242                    'textarea': true,
3243                    'template': true
3244                };
3245
3246                // Use an overridable method for retrieving binding handlers so that plugins may support dynamically created handlers
3247                ko['getBindingHandler'] = function (bindingKey) {
3248                    return ko.bindingHandlers[bindingKey];
3249                };
3250
3251                var inheritParentVm = {};
3252
3253                // The ko.bindingContext constructor is only called directly to create the root context. For child
3254                // contexts, use bindingContext.createChildContext or bindingContext.extend.
3255                ko.bindingContext = function (dataItemOrAccessor, parentContext, dataItemAlias, extendCallback, options) {
3256
3257                    // The binding context object includes static properties for the current, parent, and root view models.
3258                    // If a view model is actually stored in an observable, the corresponding binding context object, and
3259                    // any child contexts, must be updated when the view model is changed.
3260                    function updateContext() {
3261                        // Most of the time, the context will directly get a view model object, but if a function is given,
3262                        // we call the function to retrieve the view model. If the function accesses any observables or returns
3263                        // an observable, the dependency is tracked, and those observables can later cause the binding
3264                        // context to be updated.
3265                        var dataItemOrObservable = isFunc ? realDataItemOrAccessor() : realDataItemOrAccessor,
3266                            dataItem = ko.utils.unwrapObservable(dataItemOrObservable);
3267
3268                        if (parentContext) {
3269                            // Copy $root and any custom properties from the parent context
3270                            ko.utils.extend(self, parentContext);
3271
3272                            // Copy Symbol properties
3273                            if (contextAncestorBindingInfo in parentContext) {
3274                                self[contextAncestorBindingInfo] = parentContext[contextAncestorBindingInfo];
3275                            }
3276                        } else {
3277                            self['$parents'] = [];
3278                            self['$root'] = dataItem;
3279
3280                            // Export 'ko' in the binding context so it will be available in bindings and templates
3281                            // even if 'ko' isn't exported as a global, such as when using an AMD loader.
3282                            // See https://github.com/SteveSanderson/knockout/issues/490
3283                            self['ko'] = ko;
3284                        }
3285
3286                        self[contextSubscribable] = subscribable;
3287
3288                        if (shouldInheritData) {
3289                            dataItem = self['$data'];
3290                        } else {
3291                            self['$rawData'] = dataItemOrObservable;
3292                            self['$data'] = dataItem;
3293                        }
3294
3295                        if (dataItemAlias)
3296                            self[dataItemAlias] = dataItem;
3297
3298                        // The extendCallback function is provided when creating a child context or extending a context.
3299                        // It handles the specific actions needed to finish setting up the binding context. Actions in this
3300                        // function could also add dependencies to this binding context.
3301                        if (extendCallback)
3302                            extendCallback(self, parentContext, dataItem);
3303
3304                        // When a "parent" context is given and we don't already have a dependency on its context, register a dependency on it.
3305                        // Thus whenever the parent context is updated, this context will also be updated.
3306                        if (parentContext && parentContext[contextSubscribable] && !ko.computedContext.computed().hasAncestorDependency(parentContext[contextSubscribable])) {
3307                            parentContext[contextSubscribable]();
3308                        }
3309
3310                        if (dataDependency) {
3311                            self[contextDataDependency] = dataDependency;
3312                        }
3313
3314                        return self['$data'];
3315                    }
3316
3317                    var self = this,
3318                        shouldInheritData = dataItemOrAccessor === inheritParentVm,
3319                        realDataItemOrAccessor = shouldInheritData ? undefined : dataItemOrAccessor,
3320                        isFunc = typeof (realDataItemOrAccessor) == "function" && !ko.isObservable(realDataItemOrAccessor),
3321                        nodes,
3322                        subscribable,
3323                        dataDependency = options && options['dataDependency'];
3324
3325                    if (options && options['exportDependencies']) {
3326                        // The "exportDependencies" option means that the calling code will track any dependencies and re-create
3327                        // the binding context when they change.
3328                        updateContext();
3329                    } else {
3330                        subscribable = ko.pureComputed(updateContext);
3331                        subscribable.peek();
3332
3333                        // At this point, the binding context has been initialized, and the "subscribable" computed observable is
3334                        // subscribed to any observables that were accessed in the process. If there is nothing to track, the
3335                        // computed will be inactive, and we can safely throw it away. If it's active, the computed is stored in
3336                        // the context object.
3337                        if (subscribable.isActive()) {
3338                            // Always notify because even if the model ($data) hasn't changed, other context properties might have changed
3339                            subscribable['equalityComparer'] = null;
3340                        } else {
3341                            self[contextSubscribable] = undefined;
3342                        }
3343                    }
3344                }
3345
3346                // Extend the binding context hierarchy with a new view model object. If the parent context is watching
3347                // any observables, the new child context will automatically get a dependency on the parent context.
3348                // But this does not mean that the $data value of the child context will also get updated. If the child
3349                // view model also depends on the parent view model, you must provide a function that returns the correct
3350                // view model on each update.
3351                ko.bindingContext.prototype['createChildContext'] = function (dataItemOrAccessor, dataItemAlias, extendCallback, options) {
3352                    if (!options && dataItemAlias && typeof dataItemAlias == "object") {
3353                        options = dataItemAlias;
3354                        dataItemAlias = options['as'];
3355                        extendCallback = options['extend'];
3356                    }
3357
3358                    if (dataItemAlias && options && options['noChildContext']) {
3359                        var isFunc = typeof (dataItemOrAccessor) == "function" && !ko.isObservable(dataItemOrAccessor);
3360                        return new ko.bindingContext(inheritParentVm, this, null, function (self) {
3361                            if (extendCallback)
3362                                extendCallback(self);
3363                            self[dataItemAlias] = isFunc ? dataItemOrAccessor() : dataItemOrAccessor;
3364                        }, options);
3365                    }
3366
3367                    return new ko.bindingContext(dataItemOrAccessor, this, dataItemAlias, function (self, parentContext) {
3368                        // Extend the context hierarchy by setting the appropriate pointers
3369                        self['$parentContext'] = parentContext;
3370                        self['$parent'] = parentContext['$data'];
3371                        self['$parents'] = (parentContext['$parents'] || []).slice(0);
3372                        self['$parents'].unshift(self['$parent']);
3373                        if (extendCallback)
3374                            extendCallback(self);
3375                    }, options);
3376                };
3377
3378                // Extend the binding context with new custom properties. This doesn't change the context hierarchy.
3379                // Similarly to "child" contexts, provide a function here to make sure that the correct values are set
3380                // when an observable view model is updated.
3381                ko.bindingContext.prototype['extend'] = function (properties, options) {
3382                    return new ko.bindingContext(inheritParentVm, this, null, function (self, parentContext) {
3383                        ko.utils.extend(self, typeof (properties) == "function" ? properties(self) : properties);
3384                    }, options);
3385                };
3386
3387                var boundElementDomDataKey = ko.utils.domData.nextKey();
3388
3389                function asyncContextDispose(node) {
3390                    var bindingInfo = ko.utils.domData.get(node, boundElementDomDataKey),
3391                        asyncContext = bindingInfo && bindingInfo.asyncContext;
3392                    if (asyncContext) {
3393                        bindingInfo.asyncContext = null;
3394                        asyncContext.notifyAncestor();
3395                    }
3396                }
3397                function AsyncCompleteContext(node, bindingInfo, ancestorBindingInfo) {
3398                    this.node = node;
3399                    this.bindingInfo = bindingInfo;
3400                    this.asyncDescendants = [];
3401                    this.childrenComplete = false;
3402
3403                    if (!bindingInfo.asyncContext) {
3404                        ko.utils.domNodeDisposal.addDisposeCallback(node, asyncContextDispose);
3405                    }
3406
3407                    if (ancestorBindingInfo && ancestorBindingInfo.asyncContext) {
3408                        ancestorBindingInfo.asyncContext.asyncDescendants.push(node);
3409                        this.ancestorBindingInfo = ancestorBindingInfo;
3410                    }
3411                }
3412                AsyncCompleteContext.prototype.notifyAncestor = function () {
3413                    if (this.ancestorBindingInfo && this.ancestorBindingInfo.asyncContext) {
3414                        this.ancestorBindingInfo.asyncContext.descendantComplete(this.node);
3415                    }
3416                };
3417                AsyncCompleteContext.prototype.descendantComplete = function (node) {
3418                    ko.utils.arrayRemoveItem(this.asyncDescendants, node);
3419                    if (!this.asyncDescendants.length && this.childrenComplete) {
3420                        this.completeChildren();
3421                    }
3422                };
3423                AsyncCompleteContext.prototype.completeChildren = function () {
3424                    this.childrenComplete = true;
3425                    if (this.bindingInfo.asyncContext && !this.asyncDescendants.length) {
3426                        this.bindingInfo.asyncContext = null;
3427                        ko.utils.domNodeDisposal.removeDisposeCallback(this.node, asyncContextDispose);
3428                        ko.bindingEvent.notify(this.node, ko.bindingEvent.descendantsComplete);
3429                        this.notifyAncestor();
3430                    }
3431                };
3432
3433                ko.bindingEvent = {
3434                    childrenComplete: "childrenComplete",
3435                    descendantsComplete: "descendantsComplete",
3436
3437                    subscribe: function (node, event, callback, context, options) {
3438                        var bindingInfo = ko.utils.domData.getOrSet(node, boundElementDomDataKey, {});
3439                        if (!bindingInfo.eventSubscribable) {
3440                            bindingInfo.eventSubscribable = new ko.subscribable;
3441                        }
3442                        if (options && options['notifyImmediately'] && bindingInfo.notifiedEvents[event]) {
3443                            ko.dependencyDetection.ignore(callback, context, [node]);
3444                        }
3445                        return bindingInfo.eventSubscribable.subscribe(callback, context, event);
3446                    },
3447
3448                    notify: function (node, event) {
3449                        var bindingInfo = ko.utils.domData.get(node, boundElementDomDataKey);
3450                        if (bindingInfo) {
3451                            bindingInfo.notifiedEvents[event] = true;
3452                            if (bindingInfo.eventSubscribable) {
3453                                bindingInfo.eventSubscribable['notifySubscribers'](node, event);
3454                            }
3455                            if (event == ko.bindingEvent.childrenComplete) {
3456                                if (bindingInfo.asyncContext) {
3457                                    bindingInfo.asyncContext.completeChildren();
3458                                } else if (bindingInfo.asyncContext === undefined && bindingInfo.eventSubscribable && bindingInfo.eventSubscribable.hasSubscriptionsForEvent(ko.bindingEvent.descendantsComplete)) {
3459                                    // It's currently an error to register a descendantsComplete handler for a node that was never registered as completing asynchronously.
3460                                    // That's because without the asyncContext, we don't have a way to know that all descendants have completed.
3461                                    throw new Error("descendantsComplete event not supported for bindings on this node");
3462                                }
3463                            }
3464                        }
3465                    },
3466
3467                    startPossiblyAsyncContentBinding: function (node, bindingContext) {
3468                        var bindingInfo = ko.utils.domData.getOrSet(node, boundElementDomDataKey, {});
3469
3470                        if (!bindingInfo.asyncContext) {
3471                            bindingInfo.asyncContext = new AsyncCompleteContext(node, bindingInfo, bindingContext[contextAncestorBindingInfo]);
3472                        }
3473
3474                        // If the provided context was already extended with this node's binding info, just return the extended context
3475                        if (bindingContext[contextAncestorBindingInfo] == bindingInfo) {
3476                            return bindingContext;
3477                        }
3478
3479                        return bindingContext['extend'](function (ctx) {
3480                            ctx[contextAncestorBindingInfo] = bindingInfo;
3481                        });
3482                    }
3483                };
3484
3485                // Returns the valueAccessor function for a binding value
3486                function makeValueAccessor(value) {
3487                    return function () {
3488                        return value;
3489                    };
3490                }
3491
3492                // Returns the value of a valueAccessor function
3493                function evaluateValueAccessor(valueAccessor) {
3494                    return valueAccessor();
3495                }
3496
3497                // Given a function that returns bindings, create and return a new object that contains
3498                // binding value-accessors functions. Each accessor function calls the original function
3499                // so that it always gets the latest value and all dependencies are captured. This is used
3500                // by ko.applyBindingsToNode and getBindingsAndMakeAccessors.
3501                function makeAccessorsFromFunction(callback) {
3502                    return ko.utils.objectMap(ko.dependencyDetection.ignore(callback), function (value, key) {
3503                        return function () {
3504                            return callback()[key];
3505                        };
3506                    });
3507                }
3508
3509                // Given a bindings function or object, create and return a new object that contains
3510                // binding value-accessors functions. This is used by ko.applyBindingsToNode.
3511                function makeBindingAccessors(bindings, context, node) {
3512                    if (typeof bindings === 'function') {
3513                        return makeAccessorsFromFunction(bindings.bind(null, context, node));
3514                    } else {
3515                        return ko.utils.objectMap(bindings, makeValueAccessor);
3516                    }
3517                }
3518
3519                // This function is used if the binding provider doesn't include a getBindingAccessors function.
3520                // It must be called with 'this' set to the provider instance.
3521                function getBindingsAndMakeAccessors(node, context) {
3522                    return makeAccessorsFromFunction(this['getBindings'].bind(this, node, context));
3523                }
3524
3525                function validateThatBindingIsAllowedForVirtualElements(bindingName) {
3526                    var validator = ko.virtualElements.allowedBindings[bindingName];
3527                    if (!validator)
3528                        throw new Error("The binding '" + bindingName + "' cannot be used with virtual elements")
3529                }
3530
3531                function applyBindingsToDescendantsInternal(bindingContext, elementOrVirtualElement) {
3532                    var nextInQueue = ko.virtualElements.firstChild(elementOrVirtualElement);
3533
3534                    if (nextInQueue) {
3535                        var currentChild,
3536                            provider = ko.bindingProvider['instance'],
3537                            preprocessNode = provider['preprocessNode'];
3538
3539                        // Preprocessing allows a binding provider to mutate a node before bindings are applied to it. For example it's
3540                        // possible to insert new siblings after it, and/or replace the node with a different one. This can be used to
3541                        // implement custom binding syntaxes, such as {{ value }} for string interpolation, or custom element types that
3542                        // trigger insertion of <template> contents at that point in the document.
3543                        if (preprocessNode) {
3544                            while (currentChild = nextInQueue) {
3545                                nextInQueue = ko.virtualElements.nextSibling(currentChild);
3546                                preprocessNode.call(provider, currentChild);
3547                            }
3548                            // Reset nextInQueue for the next loop
3549                            nextInQueue = ko.virtualElements.firstChild(elementOrVirtualElement);
3550                        }
3551
3552                        while (currentChild = nextInQueue) {
3553                            // Keep a record of the next child *before* applying bindings, in case the binding removes the current child from its position
3554                            nextInQueue = ko.virtualElements.nextSibling(currentChild);
3555                            applyBindingsToNodeAndDescendantsInternal(bindingContext, currentChild);
3556                        }
3557                    }
3558                    ko.bindingEvent.notify(elementOrVirtualElement, ko.bindingEvent.childrenComplete);
3559                }
3560
3561                function applyBindingsToNodeAndDescendantsInternal(bindingContext, nodeVerified) {
3562                    var bindingContextForDescendants = bindingContext;
3563
3564                    var isElement = (nodeVerified.nodeType === 1);
3565                    if (isElement) // Workaround IE <= 8 HTML parsing weirdness
3566                        ko.virtualElements.normaliseVirtualElementDomStructure(nodeVerified);
3567
3568                    // Perf optimisation: Apply bindings only if...
3569                    // (1) We need to store the binding info for the node (all element nodes)
3570                    // (2) It might have bindings (e.g., it has a data-bind attribute, or it's a marker for a containerless template)
3571                    var shouldApplyBindings = isElement || ko.bindingProvider['instance']['nodeHasBindings'](nodeVerified);
3572                    if (shouldApplyBindings)
3573                        bindingContextForDescendants = applyBindingsToNodeInternal(nodeVerified, null, bindingContext)['bindingContextForDescendants'];
3574
3575                    if (bindingContextForDescendants && !bindingDoesNotRecurseIntoElementTypes[ko.utils.tagNameLower(nodeVerified)]) {
3576                        applyBindingsToDescendantsInternal(bindingContextForDescendants, nodeVerified);
3577                    }
3578                }
3579
3580                function topologicalSortBindings(bindings) {
3581                    // Depth-first sort
3582                    var result = [],                // The list of key/handler pairs that we will return
3583                        bindingsConsidered = {},    // A temporary record of which bindings are already in 'result'
3584                        cyclicDependencyStack = []; // Keeps track of a depth-search so that, if there's a cycle, we know which bindings caused it
3585                    ko.utils.objectForEach(bindings, function pushBinding(bindingKey) {
3586                        if (!bindingsConsidered[bindingKey]) {
3587                            var binding = ko['getBindingHandler'](bindingKey);
3588                            if (binding) {
3589                                // First add dependencies (if any) of the current binding
3590                                if (binding['after']) {
3591                                    cyclicDependencyStack.push(bindingKey);
3592                                    ko.utils.arrayForEach(binding['after'], function (bindingDependencyKey) {
3593                                        if (bindings[bindingDependencyKey]) {
3594                                            if (ko.utils.arrayIndexOf(cyclicDependencyStack, bindingDependencyKey) !== -1) {
3595                                                throw Error("Cannot combine the following bindings, because they have a cyclic dependency: " + cyclicDependencyStack.join(", "));
3596                                            } else {
3597                                                pushBinding(bindingDependencyKey);
3598                                            }
3599                                        }
3600                                    });
3601                                    cyclicDependencyStack.length--;
3602                                }
3603                                // Next add the current binding
3604                                result.push({ key: bindingKey, handler: binding });
3605                            }
3606                            bindingsConsidered[bindingKey] = true;
3607                        }
3608                    });
3609
3610                    return result;
3611                }
3612
3613                function applyBindingsToNodeInternal(node, sourceBindings, bindingContext) {
3614                    var bindingInfo = ko.utils.domData.getOrSet(node, boundElementDomDataKey, {});
3615
3616                    // Prevent multiple applyBindings calls for the same node, except when a binding value is specified
3617                    var alreadyBound = bindingInfo.alreadyBound;
3618                    if (!sourceBindings) {
3619                        if (alreadyBound) {
3620                            throw Error("You cannot apply bindings multiple times to the same element.");
3621                        }
3622                        bindingInfo.alreadyBound = true;
3623                    }
3624                    if (!alreadyBound) {
3625                        bindingInfo.context = bindingContext;
3626                    }
3627                    if (!bindingInfo.notifiedEvents) {
3628                        bindingInfo.notifiedEvents = {};
3629                    }
3630
3631                    // Use bindings if given, otherwise fall back on asking the bindings provider to give us some bindings
3632                    var bindings;
3633                    if (sourceBindings && typeof sourceBindings !== 'function') {
3634                        bindings = sourceBindings;
3635                    } else {
3636                        var provider = ko.bindingProvider['instance'],
3637                            getBindings = provider['getBindingAccessors'] || getBindingsAndMakeAccessors;
3638
3639                        // Get the binding from the provider within a computed observable so that we can update the bindings whenever
3640                        // the binding context is updated or if the binding provider accesses observables.
3641                        var bindingsUpdater = ko.dependentObservable(
3642                            function () {
3643                                bindings = sourceBindings ? sourceBindings(bindingContext, node) : getBindings.call(provider, node, bindingContext);
3644                                // Register a dependency on the binding context to support observable view models.
3645                                if (bindings) {
3646                                    if (bindingContext[contextSubscribable]) {
3647                                        bindingContext[contextSubscribable]();
3648                                    }
3649                                    if (bindingContext[contextDataDependency]) {
3650                                        bindingContext[contextDataDependency]();
3651                                    }
3652                                }
3653                                return bindings;
3654                            },
3655                            null, { disposeWhenNodeIsRemoved: node }
3656                        );
3657
3658                        if (!bindings || !bindingsUpdater.isActive())
3659                            bindingsUpdater = null;
3660                    }
3661
3662                    var contextToExtend = bindingContext;
3663                    var bindingHandlerThatControlsDescendantBindings;
3664                    if (bindings) {
3665                        // Return the value accessor for a given binding. When bindings are static (won't be updated because of a binding
3666                        // context update), just return the value accessor from the binding. Otherwise, return a function that always gets
3667                        // the latest binding value and registers a dependency on the binding updater.
3668                        var getValueAccessor = bindingsUpdater
3669                            ? function (bindingKey) {
3670                                return function () {
3671                                    return evaluateValueAccessor(bindingsUpdater()[bindingKey]);
3672                                };
3673                            } : function (bindingKey) {
3674                                return bindings[bindingKey];
3675                            };
3676
3677                        // Use of allBindings as a function is maintained for backwards compatibility, but its use is deprecated
3678                        function allBindings() {
3679                            return ko.utils.objectMap(bindingsUpdater ? bindingsUpdater() : bindings, evaluateValueAccessor);
3680                        }
3681                        // The following is the 3.x allBindings API
3682                        allBindings['get'] = function (key) {
3683                            return bindings[key] && evaluateValueAccessor(getValueAccessor(key));
3684                        };
3685                        allBindings['has'] = function (key) {
3686                            return key in bindings;
3687                        };
3688
3689                        if (ko.bindingEvent.childrenComplete in bindings) {
3690                            ko.bindingEvent.subscribe(node, ko.bindingEvent.childrenComplete, function () {
3691                                var callback = evaluateValueAccessor(bindings[ko.bindingEvent.childrenComplete]);
3692                                if (callback) {
3693                                    var nodes = ko.virtualElements.childNodes(node);
3694                                    if (nodes.length) {
3695                                        callback(nodes, ko.dataFor(nodes[0]));
3696                                    }
3697                                }
3698                            });
3699                        }
3700
3701                        if (ko.bindingEvent.descendantsComplete in bindings) {
3702                            contextToExtend = ko.bindingEvent.startPossiblyAsyncContentBinding(node, bindingContext);
3703                            ko.bindingEvent.subscribe(node, ko.bindingEvent.descendantsComplete, function () {
3704                                var callback = evaluateValueAccessor(bindings[ko.bindingEvent.descendantsComplete]);
3705                                if (callback && ko.virtualElements.firstChild(node)) {
3706                                    callback(node);
3707                                }
3708                            });
3709                        }
3710
3711                        // First put the bindings into the right order
3712                        var orderedBindings = topologicalSortBindings(bindings);
3713
3714                        // Go through the sorted bindings, calling init and update for each
3715                        ko.utils.arrayForEach(orderedBindings, function (bindingKeyAndHandler) {
3716                            // Note that topologicalSortBindings has already filtered out any nonexistent binding handlers,
3717                            // so bindingKeyAndHandler.handler will always be nonnull.
3718                            var handlerInitFn = bindingKeyAndHandler.handler["init"],
3719                                handlerUpdateFn = bindingKeyAndHandler.handler["update"],
3720                                bindingKey = bindingKeyAndHandler.key;
3721
3722                            if (node.nodeType === 8) {
3723                                validateThatBindingIsAllowedForVirtualElements(bindingKey);
3724                            }
3725
3726                            try {
3727                                // Run init, ignoring any dependencies
3728                                if (typeof handlerInitFn == "function") {
3729                                    ko.dependencyDetection.ignore(function () {
3730                                        var initResult = handlerInitFn(node, getValueAccessor(bindingKey), allBindings, contextToExtend['$data'], contextToExtend);
3731
3732                                        // If this binding handler claims to control descendant bindings, make a note of this
3733                                        if (initResult && initResult['controlsDescendantBindings']) {
3734                                            if (bindingHandlerThatControlsDescendantBindings !== undefined)
3735                                                throw new Error("Multiple bindings (" + bindingHandlerThatControlsDescendantBindings + " and " + bindingKey + ") are trying to control descendant bindings of the same element. You cannot use these bindings together on the same element.");
3736                                            bindingHandlerThatControlsDescendantBindings = bindingKey;
3737                                        }
3738                                    });
3739                                }
3740
3741                                // Run update in its own computed wrapper
3742                                if (typeof handlerUpdateFn == "function") {
3743                                    ko.dependentObservable(
3744                                        function () {
3745                                            handlerUpdateFn(node, getValueAccessor(bindingKey), allBindings, contextToExtend['$data'], contextToExtend);
3746                                        },
3747                                        null,
3748                                        { disposeWhenNodeIsRemoved: node }
3749                                    );
3750                                }
3751                            } catch (ex) {
3752                                ex.message = "Unable to process binding \"" + bindingKey + ": " + bindings[bindingKey] + "\"\nMessage: " + ex.message;
3753                                throw ex;
3754                            }
3755                        });
3756                    }
3757
3758                    var shouldBindDescendants = bindingHandlerThatControlsDescendantBindings === undefined;
3759                    return {
3760                        'shouldBindDescendants': shouldBindDescendants,
3761                        'bindingContextForDescendants': shouldBindDescendants && contextToExtend
3762                    };
3763                };
3764
3765                ko.storedBindingContextForNode = function (node) {
3766                    var bindingInfo = ko.utils.domData.get(node, boundElementDomDataKey);
3767                    return bindingInfo && bindingInfo.context;
3768                }
3769
3770                function getBindingContext(viewModelOrBindingContext, extendContextCallback) {
3771                    return viewModelOrBindingContext && (viewModelOrBindingContext instanceof ko.bindingContext)
3772                        ? viewModelOrBindingContext
3773                        : new ko.bindingContext(viewModelOrBindingContext, undefined, undefined, extendContextCallback);
3774                }
3775
3776                ko.applyBindingAccessorsToNode = function (node, bindings, viewModelOrBindingContext) {
3777                    if (node.nodeType === 1) // If it's an element, workaround IE <= 8 HTML parsing weirdness
3778                        ko.virtualElements.normaliseVirtualElementDomStructure(node);
3779                    return applyBindingsToNodeInternal(node, bindings, getBindingContext(viewModelOrBindingContext));
3780                };
3781
3782                ko.applyBindingsToNode = function (node, bindings, viewModelOrBindingContext) {
3783                    var context = getBindingContext(viewModelOrBindingContext);
3784                    return ko.applyBindingAccessorsToNode(node, makeBindingAccessors(bindings, context, node), context);
3785                };
3786
3787                ko.applyBindingsToDescendants = function (viewModelOrBindingContext, rootNode) {
3788                    if (rootNode.nodeType === 1 || rootNode.nodeType === 8)
3789                        applyBindingsToDescendantsInternal(getBindingContext(viewModelOrBindingContext), rootNode);
3790                };
3791
3792                ko.applyBindings = function (viewModelOrBindingContext, rootNode, extendContextCallback) {
3793                    // If jQuery is loaded after Knockout, we won't initially have access to it. So save it here.
3794                    if (!jQueryInstance && window['jQuery']) {
3795                        jQueryInstance = window['jQuery'];
3796                    }
3797
3798                    if (arguments.length < 2) {
3799                        rootNode = document.body;
3800                        if (!rootNode) {
3801                            throw Error("ko.applyBindings: could not find document.body; has the document been loaded?");
3802                        }
3803                    } else if (!rootNode || (rootNode.nodeType !== 1 && rootNode.nodeType !== 8)) {
3804                        throw Error("ko.applyBindings: first parameter should be your view model; second parameter should be a DOM node");
3805                    }
3806
3807                    applyBindingsToNodeAndDescendantsInternal(getBindingContext(viewModelOrBindingContext, extendContextCallback), rootNode);
3808                };
3809
3810                // Retrieving binding context from arbitrary nodes
3811                ko.contextFor = function (node) {
3812                    // We can only do something meaningful for elements and comment nodes (in particular, not text nodes, as IE can't store domdata for them)
3813                    if (node && (node.nodeType === 1 || node.nodeType === 8)) {
3814                        return ko.storedBindingContextForNode(node);
3815                    }
3816                    return undefined;
3817                };
3818                ko.dataFor = function (node) {
3819                    var context = ko.contextFor(node);
3820                    return context ? context['$data'] : undefined;
3821                };
3822
3823                ko.exportSymbol('bindingHandlers', ko.bindingHandlers);
3824                ko.exportSymbol('bindingEvent', ko.bindingEvent);
3825                ko.exportSymbol('bindingEvent.subscribe', ko.bindingEvent.subscribe);
3826                ko.exportSymbol('bindingEvent.startPossiblyAsyncContentBinding', ko.bindingEvent.startPossiblyAsyncContentBinding);
3827                ko.exportSymbol('applyBindings', ko.applyBindings);
3828                ko.exportSymbol('applyBindingsToDescendants', ko.applyBindingsToDescendants);
3829                ko.exportSymbol('applyBindingAccessorsToNode', ko.applyBindingAccessorsToNode);
3830                ko.exportSymbol('applyBindingsToNode', ko.applyBindingsToNode);
3831                ko.exportSymbol('contextFor', ko.contextFor);
3832                ko.exportSymbol('dataFor', ko.dataFor);
3833            })();
3834            (function (undefined) {
3835                var loadingSubscribablesCache = {}, // Tracks component loads that are currently in flight
3836                    loadedDefinitionsCache = {};    // Tracks component loads that have already completed
3837
3838                ko.components = {
3839                    get: function (componentName, callback) {
3840                        var cachedDefinition = getObjectOwnProperty(loadedDefinitionsCache, componentName);
3841                        if (cachedDefinition) {
3842                            // It's already loaded and cached. Reuse the same definition object.
3843                            // Note that for API consistency, even cache hits complete asynchronously by default.
3844                            // You can bypass this by putting synchronous:true on your component config.
3845                            if (cachedDefinition.isSynchronousComponent) {
3846                                ko.dependencyDetection.ignore(function () { // See comment in loaderRegistryBehaviors.js for reasoning
3847                                    callback(cachedDefinition.definition);
3848                                });
3849                            } else {
3850                                ko.tasks.schedule(function () { callback(cachedDefinition.definition); });
3851                            }
3852                        } else {
3853                            // Join the loading process that is already underway, or start a new one.
3854                            loadComponentAndNotify(componentName, callback);
3855                        }
3856                    },
3857
3858                    clearCachedDefinition: function (componentName) {
3859                        delete loadedDefinitionsCache[componentName];
3860                    },
3861
3862                    _getFirstResultFromLoaders: getFirstResultFromLoaders
3863                };
3864
3865                function getObjectOwnProperty(obj, propName) {
3866                    return Object.prototype.hasOwnProperty.call(obj, propName) ? obj[propName] : undefined;
3867                }
3868
3869                function loadComponentAndNotify(componentName, callback) {
3870                    var subscribable = getObjectOwnProperty(loadingSubscribablesCache, componentName),
3871                        completedAsync;
3872                    if (!subscribable) {
3873                        // It's not started loading yet. Start loading, and when it's done, move it to loadedDefinitionsCache.
3874                        subscribable = loadingSubscribablesCache[componentName] = new ko.subscribable();
3875                        subscribable.subscribe(callback);
3876
3877                        beginLoadingComponent(componentName, function (definition, config) {
3878                            var isSynchronousComponent = !!(config && config['synchronous']);
3879                            loadedDefinitionsCache[componentName] = { definition: definition, isSynchronousComponent: isSynchronousComponent };
3880                            delete loadingSubscribablesCache[componentName];
3881
3882                            // For API consistency, all loads complete asynchronously. However we want to avoid
3883                            // adding an extra task schedule if it's unnecessary (i.e., the completion is already
3884                            // async).
3885                            //
3886                            // You can bypass the 'always asynchronous' feature by putting the synchronous:true
3887                            // flag on your component configuration when you register it.
3888                            if (completedAsync || isSynchronousComponent) {
3889                                // Note that notifySubscribers ignores any dependencies read within the callback.
3890                                // See comment in loaderRegistryBehaviors.js for reasoning
3891                                subscribable['notifySubscribers'](definition);
3892                            } else {
3893                                ko.tasks.schedule(function () {
3894                                    subscribable['notifySubscribers'](definition);
3895                                });
3896                            }
3897                        });
3898                        completedAsync = true;
3899                    } else {
3900                        subscribable.subscribe(callback);
3901                    }
3902                }
3903
3904                function beginLoadingComponent(componentName, callback) {
3905                    getFirstResultFromLoaders('getConfig', [componentName], function (config) {
3906                        if (config) {
3907                            // We have a config, so now load its definition
3908                            getFirstResultFromLoaders('loadComponent', [componentName, config], function (definition) {
3909                                callback(definition, config);
3910                            });
3911                        } else {
3912                            // The component has no config - it's unknown to all the loaders.
3913                            // Note that this is not an error (e.g., a module loading error) - that would abort the
3914                            // process and this callback would not run. For this callback to run, all loaders must
3915                            // have confirmed they don't know about this component.
3916                            callback(null, null);
3917                        }
3918                    });
3919                }
3920
3921                function getFirstResultFromLoaders(methodName, argsExceptCallback, callback, candidateLoaders) {
3922                    // On the first call in the stack, start with the full set of loaders
3923                    if (!candidateLoaders) {
3924                        candidateLoaders = ko.components['loaders'].slice(0); // Use a copy, because we'll be mutating this array
3925                    }
3926
3927                    // Try the next candidate
3928                    var currentCandidateLoader = candidateLoaders.shift();
3929                    if (currentCandidateLoader) {
3930                        var methodInstance = currentCandidateLoader[methodName];
3931                        if (methodInstance) {
3932                            var wasAborted = false,
3933                                synchronousReturnValue = methodInstance.apply(currentCandidateLoader, argsExceptCallback.concat(function (result) {
3934                                    if (wasAborted) {
3935                                        callback(null);
3936                                    } else if (result !== null) {
3937                                        // This candidate returned a value. Use it.
3938                                        callback(result);
3939                                    } else {
3940                                        // Try the next candidate
3941                                        getFirstResultFromLoaders(methodName, argsExceptCallback, callback, candidateLoaders);
3942                                    }
3943                                }));
3944
3945                            // Currently, loaders may not return anything synchronously. This leaves open the possibility
3946                            // that we'll extend the API to support synchronous return values in the future. It won't be
3947                            // a breaking change, because currently no loader is allowed to return anything except undefined.
3948                            if (synchronousReturnValue !== undefined) {
3949                                wasAborted = true;
3950
3951                                // Method to suppress exceptions will remain undocumented. This is only to keep
3952                                // KO's specs running tidily, since we can observe the loading got aborted without
3953                                // having exceptions cluttering up the console too.
3954                                if (!currentCandidateLoader['suppressLoaderExceptions']) {
3955                                    throw new Error('Component loaders must supply values by invoking the callback, not by returning values synchronously.');
3956                                }
3957                            }
3958                        } else {
3959                            // This candidate doesn't have the relevant handler. Synchronously move on to the next one.
3960                            getFirstResultFromLoaders(methodName, argsExceptCallback, callback, candidateLoaders);
3961                        }
3962                    } else {
3963                        // No candidates returned a value
3964                        callback(null);
3965                    }
3966                }
3967
3968                // Reference the loaders via string name so it's possible for developers
3969                // to replace the whole array by assigning to ko.components.loaders
3970                ko.components['loaders'] = [];
3971
3972                ko.exportSymbol('components', ko.components);
3973                ko.exportSymbol('components.get', ko.components.get);
3974                ko.exportSymbol('components.clearCachedDefinition', ko.components.clearCachedDefinition);
3975            })();
3976            (function (undefined) {
3977
3978                // The default loader is responsible for two things:
3979                // 1. Maintaining the default in-memory registry of component configuration objects
3980                //    (i.e., the thing you're writing to when you call ko.components.register(someName, ...))
3981                // 2. Answering requests for components by fetching configuration objects
3982                //    from that default in-memory registry and resolving them into standard
3983                //    component definition objects (of the form { createViewModel: ..., template: ... })
3984                // Custom loaders may override either of these facilities, i.e.,
3985                // 1. To supply configuration objects from some other source (e.g., conventions)
3986                // 2. Or, to resolve configuration objects by loading viewmodels/templates via arbitrary logic.
3987
3988                var defaultConfigRegistry = {};
3989
3990                ko.components.register = function (componentName, config) {
3991                    if (!config) {
3992                        throw new Error('Invalid configuration for ' + componentName);
3993                    }
3994
3995                    if (ko.components.isRegistered(componentName)) {
3996                        throw new Error('Component ' + componentName + ' is already registered');
3997                    }
3998
3999                    defaultConfigRegistry[componentName] = config;
4000                };
4001
4002                ko.components.isRegistered = function (componentName) {
4003                    return Object.prototype.hasOwnProperty.call(defaultConfigRegistry, componentName);
4004                };
4005
4006                ko.components.unregister = function (componentName) {
4007                    delete defaultConfigRegistry[componentName];
4008                    ko.components.clearCachedDefinition(componentName);
4009                };
4010
4011                ko.components.defaultLoader = {
4012                    'getConfig': function (componentName, callback) {
4013                        var result = ko.components.isRegistered(componentName)
4014                            ? defaultConfigRegistry[componentName]
4015                            : null;
4016                        callback(result);
4017                    },
4018
4019                    'loadComponent': function (componentName, config, callback) {
4020                        var errorCallback = makeErrorCallback(componentName);
4021                        possiblyGetConfigFromAmd(errorCallback, config, function (loadedConfig) {
4022                            resolveConfig(componentName, errorCallback, loadedConfig, callback);
4023                        });
4024                    },
4025
4026                    'loadTemplate': function (componentName, templateConfig, callback) {
4027                        resolveTemplate(makeErrorCallback(componentName), templateConfig, callback);
4028                    },
4029
4030                    'loadViewModel': function (componentName, viewModelConfig, callback) {
4031                        resolveViewModel(makeErrorCallback(componentName), viewModelConfig, callback);
4032                    }
4033                };
4034
4035                var createViewModelKey = 'createViewModel';
4036
4037                // Takes a config object of the form { template: ..., viewModel: ... }, and asynchronously convert it
4038                // into the standard component definition format:
4039                //    { template: <ArrayOfDomNodes>, createViewModel: function(params, componentInfo) { ... } }.
4040                // Since both template and viewModel may need to be resolved asynchronously, both tasks are performed
4041                // in parallel, and the results joined when both are ready. We don't depend on any promises infrastructure,
4042                // so this is implemented manually below.
4043                function resolveConfig(componentName, errorCallback, config, callback) {
4044                    var result = {},
4045                        makeCallBackWhenZero = 2,
4046                        tryIssueCallback = function () {
4047                            if (--makeCallBackWhenZero === 0) {
4048                                callback(result);
4049                            }
4050                        },
4051                        templateConfig = config['template'],
4052                        viewModelConfig = config['viewModel'];
4053
4054                    if (templateConfig) {
4055                        possiblyGetConfigFromAmd(errorCallback, templateConfig, function (loadedConfig) {
4056                            ko.components._getFirstResultFromLoaders('loadTemplate', [componentName, loadedConfig], function (resolvedTemplate) {
4057                                result['template'] = resolvedTemplate;
4058                                tryIssueCallback();
4059                            });
4060                        });
4061                    } else {
4062                        tryIssueCallback();
4063                    }
4064
4065                    if (viewModelConfig) {
4066                        possiblyGetConfigFromAmd(errorCallback, viewModelConfig, function (loadedConfig) {
4067                            ko.components._getFirstResultFromLoaders('loadViewModel', [componentName, loadedConfig], function (resolvedViewModel) {
4068                                result[createViewModelKey] = resolvedViewModel;
4069                                tryIssueCallback();
4070                            });
4071                        });
4072                    } else {
4073                        tryIssueCallback();
4074                    }
4075                }
4076
4077                function resolveTemplate(errorCallback, templateConfig, callback) {
4078                    if (typeof templateConfig === 'string') {
4079                        // Markup - parse it
4080                        callback(ko.utils.parseHtmlFragment(templateConfig));
4081                    } else if (templateConfig instanceof Array) {
4082                        // Assume already an array of DOM nodes - pass through unchanged
4083                        callback(templateConfig);
4084                    } else if (isDocumentFragment(templateConfig)) {
4085                        // Document fragment - use its child nodes
4086                        callback(ko.utils.makeArray(templateConfig.childNodes));
4087                    } else if (templateConfig['element']) {
4088                        var element = templateConfig['element'];
4089                        if (isDomElement(element)) {
4090                            // Element instance - copy its child nodes
4091                            callback(cloneNodesFromTemplateSourceElement(element));
4092                        } else if (typeof element === 'string') {
4093                            // Element ID - find it, then copy its child nodes
4094                            var elemInstance = document.getElementById(element);
4095                            if (elemInstance) {
4096                                callback(cloneNodesFromTemplateSourceElement(elemInstance));
4097                            } else {
4098                                errorCallback('Cannot find element with ID ' + element);
4099                            }
4100                        } else {
4101                            errorCallback('Unknown element type: ' + element);
4102                        }
4103                    } else {
4104                        errorCallback('Unknown template value: ' + templateConfig);
4105                    }
4106                }
4107
4108                function resolveViewModel(errorCallback, viewModelConfig, callback) {
4109                    if (typeof viewModelConfig === 'function') {
4110                        // Constructor - convert to standard factory function format
4111                        // By design, this does *not* supply componentInfo to the constructor, as the intent is that
4112                        // componentInfo contains non-viewmodel data (e.g., the component's element) that should only
4113                        // be used in factory functions, not viewmodel constructors.
4114                        callback(function (params /*, componentInfo */) {
4115                            return new viewModelConfig(params);
4116                        });
4117                    } else if (typeof viewModelConfig[createViewModelKey] === 'function') {
4118                        // Already a factory function - use it as-is
4119                        callback(viewModelConfig[createViewModelKey]);
4120                    } else if ('instance' in viewModelConfig) {
4121                        // Fixed object instance - promote to createViewModel format for API consistency
4122                        var fixedInstance = viewModelConfig['instance'];
4123                        callback(function (params, componentInfo) {
4124                            return fixedInstance;
4125                        });
4126                    } else if ('viewModel' in viewModelConfig) {
4127                        // Resolved AMD module whose value is of the form { viewModel: ... }
4128                        resolveViewModel(errorCallback, viewModelConfig['viewModel'], callback);
4129                    } else {
4130                        errorCallback('Unknown viewModel value: ' + viewModelConfig);
4131                    }
4132                }
4133
4134                function cloneNodesFromTemplateSourceElement(elemInstance) {
4135                    switch (ko.utils.tagNameLower(elemInstance)) {
4136                        case 'script':
4137                            return ko.utils.parseHtmlFragment(elemInstance.text);
4138                        case 'textarea':
4139                            return ko.utils.parseHtmlFragment(elemInstance.value);
4140                        case 'template':
4141                            // For browsers with proper <template> element support (i.e., where the .content property
4142                            // gives a document fragment), use that document fragment.
4143                            if (isDocumentFragment(elemInstance.content)) {
4144                                return ko.utils.cloneNodes(elemInstance.content.childNodes);
4145                            }
4146                    }
4147
4148                    // Regular elements such as <div>, and <template> elements on old browsers that don't really
4149                    // understand <template> and just treat it as a regular container
4150                    return ko.utils.cloneNodes(elemInstance.childNodes);
4151                }
4152
4153                function isDomElement(obj) {
4154                    if (window['HTMLElement']) {
4155                        return obj instanceof HTMLElement;
4156                    } else {
4157                        return obj && obj.tagName && obj.nodeType === 1;
4158                    }
4159                }
4160
4161                function isDocumentFragment(obj) {
4162                    if (window['DocumentFragment']) {
4163                        return obj instanceof DocumentFragment;
4164                    } else {
4165                        return obj && obj.nodeType === 11;
4166                    }
4167                }
4168
4169                function possiblyGetConfigFromAmd(errorCallback, config, callback) {
4170                    if (typeof config['require'] === 'string') {
4171                        // The config is the value of an AMD module
4172                        if (amdRequire || window['require']) {
4173                            (amdRequire || window['require'])([config['require']], function (module) {
4174                                if (module && typeof module === 'object' && module.__esModule && module.default) {
4175                                    module = module.default;
4176                                }
4177                                callback(module);
4178                            });
4179                        } else {
4180                            errorCallback('Uses require, but no AMD loader is present');
4181                        }
4182                    } else {
4183                        callback(config);
4184                    }
4185                }
4186
4187                function makeErrorCallback(componentName) {
4188                    return function (message) {
4189                        throw new Error('Component \'' + componentName + '\': ' + message);
4190                    };
4191                }
4192
4193                ko.exportSymbol('components.register', ko.components.register);
4194                ko.exportSymbol('components.isRegistered', ko.components.isRegistered);
4195                ko.exportSymbol('components.unregister', ko.components.unregister);
4196
4197                // Expose the default loader so that developers can directly ask it for configuration
4198                // or to resolve configuration
4199                ko.exportSymbol('components.defaultLoader', ko.components.defaultLoader);
4200
4201                // By default, the default loader is the only registered component loader
4202                ko.components['loaders'].push(ko.components.defaultLoader);
4203
4204                // Privately expose the underlying config registry for use in old-IE shim
4205                ko.components._allRegisteredComponents = defaultConfigRegistry;
4206            })();
4207            (function (undefined) {
4208                // Overridable API for determining which component name applies to a given node. By overriding this,
4209                // you can for example map specific tagNames to components that are not preregistered.
4210                ko.components['getComponentNameForNode'] = function (node) {
4211                    var tagNameLower = ko.utils.tagNameLower(node);
4212                    if (ko.components.isRegistered(tagNameLower)) {
4213                        // Try to determine that this node can be considered a *custom* element; see https://github.com/knockout/knockout/issues/1603
4214                        if (tagNameLower.indexOf('-') != -1 || ('' + node) == "[object HTMLUnknownElement]" || (ko.utils.ieVersion <= 8 && node.tagName === tagNameLower)) {
4215                            return tagNameLower;
4216                        }
4217                    }
4218                };
4219
4220                ko.components.addBindingsForCustomElement = function (allBindings, node, bindingContext, valueAccessors) {
4221                    // Determine if it's really a custom element matching a component
4222                    if (node.nodeType === 1) {
4223                        var componentName = ko.components['getComponentNameForNode'](node);
4224                        if (componentName) {
4225                            // It does represent a component, so add a component binding for it
4226                            allBindings = allBindings || {};
4227
4228                            if (allBindings['component']) {
4229                                // Avoid silently overwriting some other 'component' binding that may already be on the element
4230                                throw new Error('Cannot use the "component" binding on a custom element matching a component');
4231                            }
4232
4233                            var componentBindingValue = { 'name': componentName, 'params': getComponentParamsFromCustomElement(node, bindingContext) };
4234
4235                            allBindings['component'] = valueAccessors
4236                                ? function () { return componentBindingValue; }
4237                                : componentBindingValue;
4238                        }
4239                    }
4240
4241                    return allBindings;
4242                }
4243
4244                var nativeBindingProviderInstance = new ko.bindingProvider();
4245
4246                function getComponentParamsFromCustomElement(elem, bindingContext) {
4247                    var paramsAttribute = elem.getAttribute('params');
4248
4249                    if (paramsAttribute) {
4250                        var params = nativeBindingProviderInstance['parseBindingsString'](paramsAttribute, bindingContext, elem, { 'valueAccessors': true, 'bindingParams': true }),
4251                            rawParamComputedValues = ko.utils.objectMap(params, function (paramValue, paramName) {
4252                                return ko.computed(paramValue, null, { disposeWhenNodeIsRemoved: elem });
4253                            }),
4254                            result = ko.utils.objectMap(rawParamComputedValues, function (paramValueComputed, paramName) {
4255                                var paramValue = paramValueComputed.peek();
4256                                // Does the evaluation of the parameter value unwrap any observables?
4257                                if (!paramValueComputed.isActive()) {
4258                                    // No it doesn't, so there's no need for any computed wrapper. Just pass through the supplied value directly.
4259                                    // Example: "someVal: firstName, age: 123" (whether or not firstName is an observable/computed)
4260                                    return paramValue;
4261                                } else {
4262                                    // Yes it does. Supply a computed property that unwraps both the outer (binding expression)
4263                                    // level of observability, and any inner (resulting model value) level of observability.
4264                                    // This means the component doesn't have to worry about multiple unwrapping. If the value is a
4265                                    // writable observable, the computed will also be writable and pass the value on to the observable.
4266                                    return ko.computed({
4267                                        'read': function () {
4268                                            return ko.utils.unwrapObservable(paramValueComputed());
4269                                        },
4270                                        'write': ko.isWriteableObservable(paramValue) && function (value) {
4271                                            paramValueComputed()(value);
4272                                        },
4273                                        disposeWhenNodeIsRemoved: elem
4274                                    });
4275                                }
4276                            });
4277
4278                        // Give access to the raw computeds, as long as that wouldn't overwrite any custom param also called '$raw'
4279                        // This is in case the developer wants to react to outer (binding) observability separately from inner
4280                        // (model value) observability, or in case the model value observable has subobservables.
4281                        if (!Object.prototype.hasOwnProperty.call(result, '$raw')) {
4282                            result['$raw'] = rawParamComputedValues;
4283                        }
4284
4285                        return result;
4286                    } else {
4287                        // For consistency, absence of a "params" attribute is treated the same as the presence of
4288                        // any empty one. Otherwise component viewmodels need special code to check whether or not
4289                        // 'params' or 'params.$raw' is null/undefined before reading subproperties, which is annoying.
4290                        return { '$raw': {} };
4291                    }
4292                }
4293
4294                // --------------------------------------------------------------------------------
4295                // Compatibility code for older (pre-HTML5) IE browsers
4296
4297                if (ko.utils.ieVersion < 9) {
4298                    // Whenever you preregister a component, enable it as a custom element in the current document
4299                    ko.components['register'] = (function (originalFunction) {
4300                        return function (componentName) {
4301                            document.createElement(componentName); // Allows IE<9 to parse markup containing the custom element
4302                            return originalFunction.apply(this, arguments);
4303                        }
4304                    })(ko.components['register']);
4305
4306                    // Whenever you create a document fragment, enable all preregistered component names as custom elements
4307                    // This is needed to make innerShiv/jQuery HTML parsing correctly handle the custom elements
4308                    document.createDocumentFragment = (function (originalFunction) {
4309                        return function () {
4310                            var newDocFrag = originalFunction(),
4311                                allComponents = ko.components._allRegisteredComponents;
4312                            for (var componentName in allComponents) {
4313                                if (Object.prototype.hasOwnProperty.call(allComponents, componentName)) {
4314                                    newDocFrag.createElement(componentName);
4315                                }
4316                            }
4317                            return newDocFrag;
4318                        };
4319                    })(document.createDocumentFragment);
4320                }
4321            })(); (function (undefined) {
4322                var componentLoadingOperationUniqueId = 0;
4323
4324                ko.bindingHandlers['component'] = {
4325                    'init': function (element, valueAccessor, ignored1, ignored2, bindingContext) {
4326                        var currentViewModel,
4327                            currentLoadingOperationId,
4328                            afterRenderSub,
4329                            disposeAssociatedComponentViewModel = function () {
4330                                var currentViewModelDispose = currentViewModel && currentViewModel['dispose'];
4331                                if (typeof currentViewModelDispose === 'function') {
4332                                    currentViewModelDispose.call(currentViewModel);
4333                                }
4334                                if (afterRenderSub) {
4335                                    afterRenderSub.dispose();
4336                                }
4337                                afterRenderSub = null;
4338                                currentViewModel = null;
4339                                // Any in-flight loading operation is no longer relevant, so make sure we ignore its completion
4340                                currentLoadingOperationId = null;
4341                            },
4342                            originalChildNodes = ko.utils.makeArray(ko.virtualElements.childNodes(element));
4343
4344                        ko.virtualElements.emptyNode(element);
4345                        ko.utils.domNodeDisposal.addDisposeCallback(element, disposeAssociatedComponentViewModel);
4346
4347                        ko.computed(function () {
4348                            var value = ko.utils.unwrapObservable(valueAccessor()),
4349                                componentName, componentParams;
4350
4351                            if (typeof value === 'string') {
4352                                componentName = value;
4353                            } else {
4354                                componentName = ko.utils.unwrapObservable(value['name']);
4355                                componentParams = ko.utils.unwrapObservable(value['params']);
4356                            }
4357
4358                            if (!componentName) {
4359                                throw new Error('No component name specified');
4360                            }
4361
4362                            var asyncContext = ko.bindingEvent.startPossiblyAsyncContentBinding(element, bindingContext);
4363
4364                            var loadingOperationId = currentLoadingOperationId = ++componentLoadingOperationUniqueId;
4365                            ko.components.get(componentName, function (componentDefinition) {
4366                                // If this is not the current load operation for this element, ignore it.
4367                                if (currentLoadingOperationId !== loadingOperationId) {
4368                                    return;
4369                                }
4370
4371                                // Clean up previous state
4372                                disposeAssociatedComponentViewModel();
4373
4374                                // Instantiate and bind new component. Implicitly this cleans any old DOM nodes.
4375                                if (!componentDefinition) {
4376                                    throw new Error('Unknown component \'' + componentName + '\'');
4377                                }
4378                                cloneTemplateIntoElement(componentName, componentDefinition, element);
4379
4380                                var componentInfo = {
4381                                    'element': element,
4382                                    'templateNodes': originalChildNodes
4383                                };
4384
4385                                var componentViewModel = createViewModel(componentDefinition, componentParams, componentInfo),
4386                                    childBindingContext = asyncContext['createChildContext'](componentViewModel, {
4387                                        'extend': function (ctx) {
4388                                            ctx['$component'] = componentViewModel;
4389                                            ctx['$componentTemplateNodes'] = originalChildNodes;
4390                                        }
4391                                    });
4392
4393                                if (componentViewModel && componentViewModel['koDescendantsComplete']) {
4394                                    afterRenderSub = ko.bindingEvent.subscribe(element, ko.bindingEvent.descendantsComplete, componentViewModel['koDescendantsComplete'], componentViewModel);
4395                                }
4396
4397                                currentViewModel = componentViewModel;
4398                                ko.applyBindingsToDescendants(childBindingContext, element);
4399                            });
4400                        }, null, { disposeWhenNodeIsRemoved: element });
4401
4402                        return { 'controlsDescendantBindings': true };
4403                    }
4404                };
4405
4406                ko.virtualElements.allowedBindings['component'] = true;
4407
4408                function cloneTemplateIntoElement(componentName, componentDefinition, element) {
4409                    var template = componentDefinition['template'];
4410                    if (!template) {
4411                        throw new Error('Component \'' + componentName + '\' has no template');
4412                    }
4413
4414                    var clonedNodesArray = ko.utils.cloneNodes(template);
4415                    ko.virtualElements.setDomNodeChildren(element, clonedNodesArray);
4416                }
4417
4418                function createViewModel(componentDefinition, componentParams, componentInfo) {
4419                    var componentViewModelFactory = componentDefinition['createViewModel'];
4420                    return componentViewModelFactory
4421                        ? componentViewModelFactory.call(componentDefinition, componentParams, componentInfo)
4422                        : componentParams; // Template-only component
4423                }
4424
4425            })();
4426            var attrHtmlToJavaScriptMap = { 'class': 'className', 'for': 'htmlFor' };
4427            ko.bindingHandlers['attr'] = {
4428                'update': function (element, valueAccessor, allBindings) {
4429                    var value = ko.utils.unwrapObservable(valueAccessor()) || {};
4430                    ko.utils.objectForEach(value, function (attrName, attrValue) {
4431                        attrValue = ko.utils.unwrapObservable(attrValue);
4432
4433                        // Find the namespace of this attribute, if any.
4434                        var prefixLen = attrName.indexOf(':');
4435                        var namespace = "lookupNamespaceURI" in element && prefixLen > 0 && element.lookupNamespaceURI(attrName.substr(0, prefixLen));
4436
4437                        // To cover cases like "attr: { checked:someProp }", we want to remove the attribute entirely
4438                        // when someProp is a "no value"-like value (strictly null, false, or undefined)
4439                        // (because the absence of the "checked" attr is how to mark an element as not checked, etc.)
4440                        var toRemove = (attrValue === false) || (attrValue === null) || (attrValue === undefined);
4441                        if (toRemove) {
4442                            namespace ? element.removeAttributeNS(namespace, attrName) : element.removeAttribute(attrName);
4443                        } else {
4444                            attrValue = attrValue.toString();
4445                        }
4446
4447                        // In IE <= 7 and IE8 Quirks Mode, you have to use the JavaScript property name instead of the
4448                        // HTML attribute name for certain attributes. IE8 Standards Mode supports the correct behavior,
4449                        // but instead of figuring out the mode, we'll just set the attribute through the JavaScript
4450                        // property for IE <= 8.
4451                        if (ko.utils.ieVersion <= 8 && attrName in attrHtmlToJavaScriptMap) {
4452                            attrName = attrHtmlToJavaScriptMap[attrName];
4453                            if (toRemove)
4454                                element.removeAttribute(attrName);
4455                            else
4456                                element[attrName] = attrValue;
4457                        } else if (!toRemove) {
4458                            namespace ? element.setAttributeNS(namespace, attrName, attrValue) : element.setAttribute(attrName, attrValue);
4459                        }
4460
4461                        // Treat "name" specially - although you can think of it as an attribute, it also needs
4462                        // special handling on older versions of IE (https://github.com/SteveSanderson/knockout/pull/333)
4463                        // Deliberately being case-sensitive here because XHTML would regard "Name" as a different thing
4464                        // entirely, and there's no strong reason to allow for such casing in HTML.
4465                        if (attrName === "name") {
4466                            ko.utils.setElementName(element, toRemove ? "" : attrValue);
4467                        }
4468                    });
4469                }
4470            };
4471            (function () {
4472
4473                ko.bindingHandlers['checked'] = {
4474                    'after': ['value', 'attr'],
4475                    'init': function (element, valueAccessor, allBindings) {
4476                        var checkedValue = ko.pureComputed(function () {
4477                            // Treat "value" like "checkedValue" when it is included with "checked" binding
4478                            if (allBindings['has']('checkedValue')) {
4479                                return ko.utils.unwrapObservable(allBindings.get('checkedValue'));
4480                            } else if (useElementValue) {
4481                                if (allBindings['has']('value')) {
4482                                    return ko.utils.unwrapObservable(allBindings.get('value'));
4483                                } else {
4484                                    return element.value;
4485                                }
4486                            }
4487                        });
4488
4489                        function updateModel() {
4490                            // This updates the model value from the view value.
4491                            // It runs in response to DOM events (click) and changes in checkedValue.
4492                            var isChecked = element.checked,
4493                                elemValue = checkedValue();
4494
4495                            // When we're first setting up this computed, don't change any model state.
4496                            if (ko.computedContext.isInitial()) {
4497                                return;
4498                            }
4499
4500                            // We can ignore unchecked radio buttons, because some other radio
4501                            // button will be checked, and that one can take care of updating state.
4502                            // Also ignore value changes to an already unchecked checkbox.
4503                            if (!isChecked && (isRadio || ko.computedContext.getDependenciesCount())) {
4504                                return;
4505                            }
4506
4507                            var modelValue = ko.dependencyDetection.ignore(valueAccessor);
4508                            if (valueIsArray) {
4509                                var writableValue = rawValueIsNonArrayObservable ? modelValue.peek() : modelValue,
4510                                    saveOldValue = oldElemValue;
4511                                oldElemValue = elemValue;
4512
4513                                if (saveOldValue !== elemValue) {
4514                                    // When we're responding to the checkedValue changing, and the element is
4515                                    // currently checked, replace the old elem value with the new elem value
4516                                    // in the model array.
4517                                    if (isChecked) {
4518                                        ko.utils.addOrRemoveItem(writableValue, elemValue, true);
4519                                        ko.utils.addOrRemoveItem(writableValue, saveOldValue, false);
4520                                    }
4521                                } else {
4522                                    // When we're responding to the user having checked/unchecked a checkbox,
4523                                    // add/remove the element value to the model array.
4524                                    ko.utils.addOrRemoveItem(writableValue, elemValue, isChecked);
4525                                }
4526
4527                                if (rawValueIsNonArrayObservable && ko.isWriteableObservable(modelValue)) {
4528                                    modelValue(writableValue);
4529                                }
4530                            } else {
4531                                if (isCheckbox) {
4532                                    if (elemValue === undefined) {
4533                                        elemValue = isChecked;
4534                                    } else if (!isChecked) {
4535                                        elemValue = undefined;
4536                                    }
4537                                }
4538                                ko.expressionRewriting.writeValueToProperty(modelValue, allBindings, 'checked', elemValue, true);
4539                            }
4540                        };
4541
4542                        function updateView() {
4543                            // This updates the view value from the model value.
4544                            // It runs in response to changes in the bound (checked) value.
4545                            var modelValue = ko.utils.unwrapObservable(valueAccessor()),
4546                                elemValue = checkedValue();
4547
4548                            if (valueIsArray) {
4549                                // When a checkbox is bound to an array, being checked represents its value being present in that array
4550                                element.checked = ko.utils.arrayIndexOf(modelValue, elemValue) >= 0;
4551                                oldElemValue = elemValue;
4552                            } else if (isCheckbox && elemValue === undefined) {
4553                                // When a checkbox is bound to any other value (not an array) and "checkedValue" is not defined,
4554                                // being checked represents the value being trueish
4555                                element.checked = !!modelValue;
4556                            } else {
4557                                // Otherwise, being checked means that the checkbox or radio button's value corresponds to the model value
4558                                element.checked = (checkedValue() === modelValue);
4559                            }
4560                        };
4561
4562                        var isCheckbox = element.type == "checkbox",
4563                            isRadio = element.type == "radio";
4564
4565                        // Only bind to check boxes and radio buttons
4566                        if (!isCheckbox && !isRadio) {
4567                            return;
4568                        }
4569
4570                        var rawValue = valueAccessor(),
4571                            valueIsArray = isCheckbox && (ko.utils.unwrapObservable(rawValue) instanceof Array),
4572                            rawValueIsNonArrayObservable = !(valueIsArray && rawValue.push && rawValue.splice),
4573                            useElementValue = isRadio || valueIsArray,
4574                            oldElemValue = valueIsArray ? checkedValue() : undefined;
4575
4576                        // IE 6 won't allow radio buttons to be selected unless they have a name
4577                        if (isRadio && !element.name)
4578                            ko.bindingHandlers['uniqueName']['init'](element, function () { return true });
4579
4580                        // Set up two computeds to update the binding:
4581
4582                        // The first responds to changes in the checkedValue value and to element clicks
4583                        ko.computed(updateModel, null, { disposeWhenNodeIsRemoved: element });
4584                        ko.utils.registerEventHandler(element, "click", updateModel);
4585
4586                        // The second responds to changes in the model value (the one associated with the checked binding)
4587                        ko.computed(updateView, null, { disposeWhenNodeIsRemoved: element });
4588
4589                        rawValue = undefined;
4590                    }
4591                };
4592                ko.expressionRewriting.twoWayBindings['checked'] = true;
4593
4594                ko.bindingHandlers['checkedValue'] = {
4595                    'update': function (element, valueAccessor) {
4596                        element.value = ko.utils.unwrapObservable(valueAccessor());
4597                    }
4598                };
4599
4600            })(); var classesWrittenByBindingKey = '__ko__cssValue';
4601            ko.bindingHandlers['class'] = {
4602                'update': function (element, valueAccessor) {
4603                    var value = ko.utils.stringTrim(ko.utils.unwrapObservable(valueAccessor()));
4604                    ko.utils.toggleDomNodeCssClass(element, element[classesWrittenByBindingKey], false);
4605                    element[classesWrittenByBindingKey] = value;
4606                    ko.utils.toggleDomNodeCssClass(element, value, true);
4607                }
4608            };
4609
4610            ko.bindingHandlers['css'] = {
4611                'update': function (element, valueAccessor) {
4612                    var value = ko.utils.unwrapObservable(valueAccessor());
4613                    if (value !== null && typeof value == "object") {
4614                        ko.utils.objectForEach(value, function (className, shouldHaveClass) {
4615                            shouldHaveClass = ko.utils.unwrapObservable(shouldHaveClass);
4616                            ko.utils.toggleDomNodeCssClass(element, className, shouldHaveClass);
4617                        });
4618                    } else {
4619                        ko.bindingHandlers['class']['update'](element, valueAccessor);
4620                    }
4621                }
4622            };
4623            ko.bindingHandlers['enable'] = {
4624                'update': function (element, valueAccessor) {
4625                    var value = ko.utils.unwrapObservable(valueAccessor());
4626                    if (value && element.disabled)
4627                        element.removeAttribute("disabled");
4628                    else if ((!value) && (!element.disabled))
4629                        element.disabled = true;
4630                }
4631            };
4632
4633            ko.bindingHandlers['disable'] = {
4634                'update': function (element, valueAccessor) {
4635                    ko.bindingHandlers['enable']['update'](element, function () { return !ko.utils.unwrapObservable(valueAccessor()) });
4636                }
4637            };
4638            // For certain common events (currently just 'click'), allow a simplified data-binding syntax
4639            // e.g. click:handler instead of the usual full-length event:{click:handler}
4640            function makeEventHandlerShortcut(eventName) {
4641                ko.bindingHandlers[eventName] = {
4642                    'init': function (element, valueAccessor, allBindings, viewModel, bindingContext) {
4643                        var newValueAccessor = function () {
4644                            var result = {};
4645                            result[eventName] = valueAccessor();
4646                            return result;
4647                        };
4648                        return ko.bindingHandlers['event']['init'].call(this, element, newValueAccessor, allBindings, viewModel, bindingContext);
4649                    }
4650                }
4651            }
4652
4653            ko.bindingHandlers['event'] = {
4654                'init': function (element, valueAccessor, allBindings, viewModel, bindingContext) {
4655                    var eventsToHandle = valueAccessor() || {};
4656                    ko.utils.objectForEach(eventsToHandle, function (eventName) {
4657                        if (typeof eventName == "string") {
4658                            ko.utils.registerEventHandler(element, eventName, function (event) {
4659                                var handlerReturnValue;
4660                                var handlerFunction = valueAccessor()[eventName];
4661                                if (!handlerFunction)
4662                                    return;
4663
4664                                try {
4665                                    // Take all the event args, and prefix with the viewmodel
4666                                    var argsForHandler = ko.utils.makeArray(arguments);
4667                                    viewModel = bindingContext['$data'];
4668                                    argsForHandler.unshift(viewModel);
4669                                    handlerReturnValue = handlerFunction.apply(viewModel, argsForHandler);
4670                                } finally {
4671                                    if (handlerReturnValue !== true) { // Normally we want to prevent default action. Developer can override this be explicitly returning true.
4672                                        if (event.preventDefault)
4673                                            event.preventDefault();
4674                                        else
4675                                            event.returnValue = false;
4676                                    }
4677                                }
4678
4679                                var bubble = allBindings.get(eventName + 'Bubble') !== false;
4680                                if (!bubble) {
4681                                    event.cancelBubble = true;
4682                                    if (event.stopPropagation)
4683                                        event.stopPropagation();
4684                                }
4685                            });
4686                        }
4687                    });
4688                }
4689            };
4690            // "foreach: someExpression" is equivalent to "template: { foreach: someExpression }"
4691            // "foreach: { data: someExpression, afterAdd: myfn }" is equivalent to "template: { foreach: someExpression, afterAdd: myfn }"
4692            ko.bindingHandlers['foreach'] = {
4693                makeTemplateValueAccessor: function (valueAccessor) {
4694                    return function () {
4695                        var modelValue = valueAccessor(),
4696                            unwrappedValue = ko.utils.peekObservable(modelValue);    // Unwrap without setting a dependency here
4697
4698                        // If unwrappedValue is the array, pass in the wrapped value on its own
4699                        // The value will be unwrapped and tracked within the template binding
4700                        // (See https://github.com/SteveSanderson/knockout/issues/523)
4701                        if ((!unwrappedValue) || typeof unwrappedValue.length == "number")
4702                            return { 'foreach': modelValue, 'templateEngine': ko.nativeTemplateEngine.instance };
4703
4704                        // If unwrappedValue.data is the array, preserve all relevant options and unwrap again value so we get updates
4705                        ko.utils.unwrapObservable(modelValue);
4706                        return {
4707                            'foreach': unwrappedValue['data'],
4708                            'as': unwrappedValue['as'],
4709                            'noChildContext': unwrappedValue['noChildContext'],
4710                            'includeDestroyed': unwrappedValue['includeDestroyed'],
4711                            'afterAdd': unwrappedValue['afterAdd'],
4712                            'beforeRemove': unwrappedValue['beforeRemove'],
4713                            'afterRender': unwrappedValue['afterRender'],
4714                            'beforeMove': unwrappedValue['beforeMove'],
4715                            'afterMove': unwrappedValue['afterMove'],
4716                            'templateEngine': ko.nativeTemplateEngine.instance
4717                        };
4718                    };
4719                },
4720                'init': function (element, valueAccessor, allBindings, viewModel, bindingContext) {
4721                    return ko.bindingHandlers['template']['init'](element, ko.bindingHandlers['foreach'].makeTemplateValueAccessor(valueAccessor));
4722                },
4723                'update': function (element, valueAccessor, allBindings, viewModel, bindingContext) {
4724                    return ko.bindingHandlers['template']['update'](element, ko.bindingHandlers['foreach'].makeTemplateValueAccessor(valueAccessor), allBindings, viewModel, bindingContext);
4725                }
4726            };
4727            ko.expressionRewriting.bindingRewriteValidators['foreach'] = false; // Can't rewrite control flow bindings
4728            ko.virtualElements.allowedBindings['foreach'] = true;
4729            var hasfocusUpdatingProperty = '__ko_hasfocusUpdating';
4730            var hasfocusLastValue = '__ko_hasfocusLastValue';
4731            ko.bindingHandlers['hasfocus'] = {
4732                'init': function (element, valueAccessor, allBindings) {
4733                    var handleElementFocusChange = function (isFocused) {
4734                        // Where possible, ignore which event was raised and determine focus state using activeElement,
4735                        // as this avoids phantom focus/blur events raised when changing tabs in modern browsers.
4736                        // However, not all KO-targeted browsers (Firefox 2) support activeElement. For those browsers,
4737                        // prevent a loss of focus when changing tabs/windows by setting a flag that prevents hasfocus
4738                        // from calling 'blur()' on the element when it loses focus.
4739                        // Discussion at https://github.com/SteveSanderson/knockout/pull/352
4740                        element[hasfocusUpdatingProperty] = true;
4741                        var ownerDoc = element.ownerDocument;
4742                        if ("activeElement" in ownerDoc) {
4743                            var active;
4744                            try {
4745                                active = ownerDoc.activeElement;
4746                            } catch (e) {
4747                                // IE9 throws if you access activeElement during page load (see issue #703)
4748                                active = ownerDoc.body;
4749                            }
4750                            isFocused = (active === element);
4751                        }
4752                        var modelValue = valueAccessor();
4753                        ko.expressionRewriting.writeValueToProperty(modelValue, allBindings, 'hasfocus', isFocused, true);
4754
4755                        //cache the latest value, so we can avoid unnecessarily calling focus/blur in the update function
4756                        element[hasfocusLastValue] = isFocused;
4757                        element[hasfocusUpdatingProperty] = false;
4758                    };
4759                    var handleElementFocusIn = handleElementFocusChange.bind(null, true);
4760                    var handleElementFocusOut = handleElementFocusChange.bind(null, false);
4761
4762                    ko.utils.registerEventHandler(element, "focus", handleElementFocusIn);
4763                    ko.utils.registerEventHandler(element, "focusin", handleElementFocusIn); // For IE
4764                    ko.utils.registerEventHandler(element, "blur", handleElementFocusOut);
4765                    ko.utils.registerEventHandler(element, "focusout", handleElementFocusOut); // For IE
4766
4767                    // Assume element is not focused (prevents "blur" being called initially)
4768                    element[hasfocusLastValue] = false;
4769                },
4770                'update': function (element, valueAccessor) {
4771                    var value = !!ko.utils.unwrapObservable(valueAccessor());
4772
4773                    if (!element[hasfocusUpdatingProperty] && element[hasfocusLastValue] !== value) {
4774                        value ? element.focus() : element.blur();
4775
4776                        // In IE, the blur method doesn't always cause the element to lose focus (for example, if the window is not in focus).
4777                        // Setting focus to the body element does seem to be reliable in IE, but should only be used if we know that the current
4778                        // element was focused already.
4779                        if (!value && element[hasfocusLastValue]) {
4780                            element.ownerDocument.body.focus();
4781                        }
4782
4783                        // For IE, which doesn't reliably fire "focus" or "blur" events synchronously
4784                        ko.dependencyDetection.ignore(ko.utils.triggerEvent, null, [element, value ? "focusin" : "focusout"]);
4785                    }
4786                }
4787            };
4788            ko.expressionRewriting.twoWayBindings['hasfocus'] = true;
4789
4790            ko.bindingHandlers['hasFocus'] = ko.bindingHandlers['hasfocus']; // Make "hasFocus" an alias
4791            ko.expressionRewriting.twoWayBindings['hasFocus'] = 'hasfocus';
4792            ko.bindingHandlers['html'] = {
4793                'init': function () {
4794                    // Prevent binding on the dynamically-injected HTML (as developers are unlikely to expect that, and it has security implications)
4795                    return { 'controlsDescendantBindings': true };
4796                },
4797                'update': function (element, valueAccessor) {
4798                    // setHtml will unwrap the value if needed
4799                    ko.utils.setHtml(element, valueAccessor());
4800                }
4801            };
4802            (function () {
4803
4804                // Makes a binding like with or if
4805                function makeWithIfBinding(bindingKey, isWith, isNot) {
4806                    ko.bindingHandlers[bindingKey] = {
4807                        'init': function (element, valueAccessor, allBindings, viewModel, bindingContext) {
4808                            var didDisplayOnLastUpdate, savedNodes, contextOptions = {}, completeOnRender, needAsyncContext, renderOnEveryChange;
4809
4810                            if (isWith) {
4811                                var as = allBindings.get('as'), noChildContext = allBindings.get('noChildContext');
4812                                renderOnEveryChange = !(as && noChildContext);
4813                                contextOptions = { 'as': as, 'noChildContext': noChildContext, 'exportDependencies': renderOnEveryChange };
4814                            }
4815
4816                            completeOnRender = allBindings.get("completeOn") == "render";
4817                            needAsyncContext = completeOnRender || allBindings['has'](ko.bindingEvent.descendantsComplete);
4818
4819                            ko.computed(function () {
4820                                var value = ko.utils.unwrapObservable(valueAccessor()),
4821                                    shouldDisplay = !isNot !== !value, // equivalent to isNot ? !value : !!value,
4822                                    isInitial = !savedNodes,
4823                                    childContext;
4824
4825                                if (!renderOnEveryChange && shouldDisplay === didDisplayOnLastUpdate) {
4826                                    return;
4827                                }
4828
4829                                if (needAsyncContext) {
4830                                    bindingContext = ko.bindingEvent.startPossiblyAsyncContentBinding(element, bindingContext);
4831                                }
4832
4833                                if (shouldDisplay) {
4834                                    if (!isWith || renderOnEveryChange) {
4835                                        contextOptions['dataDependency'] = ko.computedContext.computed();
4836                                    }
4837
4838                                    if (isWith) {
4839                                        childContext = bindingContext['createChildContext'](typeof value == "function" ? value : valueAccessor, contextOptions);
4840                                    } else if (ko.computedContext.getDependenciesCount()) {
4841                                        childContext = bindingContext['extend'](null, contextOptions);
4842                                    } else {
4843                                        childContext = bindingContext;
4844                                    }
4845                                }
4846
4847                                // Save a copy of the inner nodes on the initial update, but only if we have dependencies.
4848                                if (isInitial && ko.computedContext.getDependenciesCount()) {
4849                                    savedNodes = ko.utils.cloneNodes(ko.virtualElements.childNodes(element), true /* shouldCleanNodes */);
4850                                }
4851
4852                                if (shouldDisplay) {
4853                                    if (!isInitial) {
4854                                        ko.virtualElements.setDomNodeChildren(element, ko.utils.cloneNodes(savedNodes));
4855                                    }
4856
4857                                    ko.applyBindingsToDescendants(childContext, element);
4858                                } else {
4859                                    ko.virtualElements.emptyNode(element);
4860
4861                                    if (!completeOnRender) {
4862                                        ko.bindingEvent.notify(element, ko.bindingEvent.childrenComplete);
4863                                    }
4864                                }
4865
4866                                didDisplayOnLastUpdate = shouldDisplay;
4867
4868                            }, null, { disposeWhenNodeIsRemoved: element });
4869
4870                            return { 'controlsDescendantBindings': true };
4871                        }
4872                    };
4873                    ko.expressionRewriting.bindingRewriteValidators[bindingKey] = false; // Can't rewrite control flow bindings
4874                    ko.virtualElements.allowedBindings[bindingKey] = true;
4875                }
4876
4877                // Construct the actual binding handlers
4878                makeWithIfBinding('if');
4879                makeWithIfBinding('ifnot', false /* isWith */, true /* isNot */);
4880                makeWithIfBinding('with', true /* isWith */);
4881
4882            })(); ko.bindingHandlers['let'] = {
4883                'init': function (element, valueAccessor, allBindings, viewModel, bindingContext) {
4884                    // Make a modified binding context, with extra properties, and apply it to descendant elements
4885                    var innerContext = bindingContext['extend'](valueAccessor);
4886                    ko.applyBindingsToDescendants(innerContext, element);
4887
4888                    return { 'controlsDescendantBindings': true };
4889                }
4890            };
4891            ko.virtualElements.allowedBindings['let'] = true;
4892            var captionPlaceholder = {};
4893            ko.bindingHandlers['options'] = {
4894                'init': function (element) {
4895                    if (ko.utils.tagNameLower(element) !== "select")
4896                        throw new Error("options binding applies only to SELECT elements");
4897
4898                    // Remove all existing <option>s.
4899                    while (element.length > 0) {
4900                        element.remove(0);
4901                    }
4902
4903                    // Ensures that the binding processor doesn't try to bind the options
4904                    return { 'controlsDescendantBindings': true };
4905                },
4906                'update': function (element, valueAccessor, allBindings) {
4907                    function selectedOptions() {
4908                        return ko.utils.arrayFilter(element.options, function (node) { return node.selected; });
4909                    }
4910
4911                    var selectWasPreviouslyEmpty = element.length == 0,
4912                        multiple = element.multiple,
4913                        previousScrollTop = (!selectWasPreviouslyEmpty && multiple) ? element.scrollTop : null,
4914                        unwrappedArray = ko.utils.unwrapObservable(valueAccessor()),
4915                        valueAllowUnset = allBindings.get('valueAllowUnset') && allBindings['has']('value'),
4916                        includeDestroyed = allBindings.get('optionsIncludeDestroyed'),
4917                        arrayToDomNodeChildrenOptions = {},
4918                        captionValue,
4919                        filteredArray,
4920                        previousSelectedValues = [];
4921
4922                    if (!valueAllowUnset) {
4923                        if (multiple) {
4924                            previousSelectedValues = ko.utils.arrayMap(selectedOptions(), ko.selectExtensions.readValue);
4925                        } else if (element.selectedIndex >= 0) {
4926                            previousSelectedValues.push(ko.selectExtensions.readValue(element.options[element.selectedIndex]));
4927                        }
4928                    }
4929
4930                    if (unwrappedArray) {
4931                        if (typeof unwrappedArray.length == "undefined") // Coerce single value into array
4932                            unwrappedArray = [unwrappedArray];
4933
4934                        // Filter out any entries marked as destroyed
4935                        filteredArray = ko.utils.arrayFilter(unwrappedArray, function (item) {
4936                            return includeDestroyed || item === undefined || item === null || !ko.utils.unwrapObservable(item['_destroy']);
4937                        });
4938
4939                        // If caption is included, add it to the array
4940                        if (allBindings['has']('optionsCaption')) {
4941                            captionValue = ko.utils.unwrapObservable(allBindings.get('optionsCaption'));
4942                            // If caption value is null or undefined, don't show a caption
4943                            if (captionValue !== null && captionValue !== undefined) {
4944                                filteredArray.unshift(captionPlaceholder);
4945                            }
4946                        }
4947                    } else {
4948                        // If a falsy value is provided (e.g. null), we'll simply empty the select element
4949                    }
4950
4951                    function applyToObject(object, predicate, defaultValue) {
4952                        var predicateType = typeof predicate;
4953                        if (predicateType == "function")    // Given a function; run it against the data value
4954                            return predicate(object);
4955                        else if (predicateType == "string") // Given a string; treat it as a property name on the data value
4956                            return object[predicate];
4957                        else                                // Given no optionsText arg; use the data value itself
4958                            return defaultValue;
4959                    }
4960
4961                    // The following functions can run at two different times:
4962                    // The first is when the whole array is being updated directly from this binding handler.
4963                    // The second is when an observable value for a specific array entry is updated.
4964                    // oldOptions will be empty in the first case, but will be filled with the previously generated option in the second.
4965                    var itemUpdate = false;
4966                    function optionForArrayItem(arrayEntry, index, oldOptions) {
4967                        if (oldOptions.length) {
4968                            previousSelectedValues = !valueAllowUnset && oldOptions[0].selected ? [ko.selectExtensions.readValue(oldOptions[0])] : [];
4969                            itemUpdate = true;
4970                        }
4971                        var option = element.ownerDocument.createElement("option");
4972                        if (arrayEntry === captionPlaceholder) {
4973                            ko.utils.setTextContent(option, allBindings.get('optionsCaption'));
4974                            ko.selectExtensions.writeValue(option, undefined);
4975                        } else {
4976                            // Apply a value to the option element
4977                            var optionValue = applyToObject(arrayEntry, allBindings.get('optionsValue'), arrayEntry);
4978                            ko.selectExtensions.writeValue(option, ko.utils.unwrapObservable(optionValue));
4979
4980                            // Apply some text to the option element
4981                            var optionText = applyToObject(arrayEntry, allBindings.get('optionsText'), optionValue);
4982                            ko.utils.setTextContent(option, optionText);
4983                        }
4984                        return [option];
4985                    }
4986
4987                    // By using a beforeRemove callback, we delay the removal until after new items are added. This fixes a selection
4988                    // problem in IE<=8 and Firefox. See https://github.com/knockout/knockout/issues/1208
4989                    arrayToDomNodeChildrenOptions['beforeRemove'] =
4990                        function (option) {
4991                            element.removeChild(option);
4992                        };
4993
4994                    function setSelectionCallback(arrayEntry, newOptions) {
4995                        if (itemUpdate && valueAllowUnset) {
4996                            // The model value is authoritative, so make sure its value is the one selected
4997                            ko.bindingEvent.notify(element, ko.bindingEvent.childrenComplete);
4998                        } else if (previousSelectedValues.length) {
4999                            // IE6 doesn't like us to assign selection to OPTION nodes before they're added to the document.
5000                            // That's why we first added them without selection. Now it's time to set the selection.
5001                            var isSelected = ko.utils.arrayIndexOf(previousSelectedValues, ko.selectExtensions.readValue(newOptions[0])) >= 0;
5002                            ko.utils.setOptionNodeSelectionState(newOptions[0], isSelected);
5003
5004                            // If this option was changed from being selected during a single-item update, notify the change
5005                            if (itemUpdate && !isSelected) {
5006                                ko.dependencyDetection.ignore(ko.utils.triggerEvent, null, [element, "change"]);
5007                            }
5008                        }
5009                    }
5010
5011                    var callback = setSelectionCallback;
5012                    if (allBindings['has']('optionsAfterRender') && typeof allBindings.get('optionsAfterRender') == "function") {
5013                        callback = function (arrayEntry, newOptions) {
5014                            setSelectionCallback(arrayEntry, newOptions);
5015                            ko.dependencyDetection.ignore(allBindings.get('optionsAfterRender'), null, [newOptions[0], arrayEntry !== captionPlaceholder ? arrayEntry : undefined]);
5016                        }
5017                    }
5018
5019                    ko.utils.setDomNodeChildrenFromArrayMapping(element, filteredArray, optionForArrayItem, arrayToDomNodeChildrenOptions, callback);
5020
5021                    if (!valueAllowUnset) {
5022                        // Determine if the selection has changed as a result of updating the options list
5023                        var selectionChanged;
5024                        if (multiple) {
5025                            // For a multiple-select box, compare the new selection count to the previous one
5026                            // But if nothing was selected before, the selection can't have changed
5027                            selectionChanged = previousSelectedValues.length && selectedOptions().length < previousSelectedValues.length;
5028                        } else {
5029                            // For a single-select box, compare the current value to the previous value
5030                            // But if nothing was selected before or nothing is selected now, just look for a change in selection
5031                            selectionChanged = (previousSelectedValues.length && element.selectedIndex >= 0)
5032                                ? (ko.selectExtensions.readValue(element.options[element.selectedIndex]) !== previousSelectedValues[0])
5033                                : (previousSelectedValues.length || element.selectedIndex >= 0);
5034                        }
5035
5036                        // Ensure consistency between model value and selected option.
5037                        // If the dropdown was changed so that selection is no longer the same,
5038                        // notify the value or selectedOptions binding.
5039                        if (selectionChanged) {
5040                            ko.dependencyDetection.ignore(ko.utils.triggerEvent, null, [element, "change"]);
5041                        }
5042                    }
5043
5044                    if (valueAllowUnset || ko.computedContext.isInitial()) {
5045                        ko.bindingEvent.notify(element, ko.bindingEvent.childrenComplete);
5046                    }
5047
5048                    // Workaround for IE bug
5049                    ko.utils.ensureSelectElementIsRenderedCorrectly(element);
5050
5051                    if (previousScrollTop && Math.abs(previousScrollTop - element.scrollTop) > 20)
5052                        element.scrollTop = previousScrollTop;
5053                }
5054            };
5055            ko.bindingHandlers['options'].optionValueDomDataKey = ko.utils.domData.nextKey();
5056            ko.bindingHandlers['selectedOptions'] = {
5057                'init': function (element, valueAccessor, allBindings) {
5058                    function updateFromView() {
5059                        var value = valueAccessor(), valueToWrite = [];
5060                        ko.utils.arrayForEach(element.getElementsByTagName("option"), function (node) {
5061                            if (node.selected)
5062                                valueToWrite.push(ko.selectExtensions.readValue(node));
5063                        });
5064                        ko.expressionRewriting.writeValueToProperty(value, allBindings, 'selectedOptions', valueToWrite);
5065                    }
5066
5067                    function updateFromModel() {
5068                        var newValue = ko.utils.unwrapObservable(valueAccessor()),
5069                            previousScrollTop = element.scrollTop;
5070
5071                        if (newValue && typeof newValue.length == "number") {
5072                            ko.utils.arrayForEach(element.getElementsByTagName("option"), function (node) {
5073                                var isSelected = ko.utils.arrayIndexOf(newValue, ko.selectExtensions.readValue(node)) >= 0;
5074                                if (node.selected != isSelected) {      // This check prevents flashing of the select element in IE
5075                                    ko.utils.setOptionNodeSelectionState(node, isSelected);
5076                                }
5077                            });
5078                        }
5079
5080                        element.scrollTop = previousScrollTop;
5081                    }
5082
5083                    if (ko.utils.tagNameLower(element) != "select") {
5084                        throw new Error("selectedOptions binding applies only to SELECT elements");
5085                    }
5086
5087                    var updateFromModelComputed;
5088                    ko.bindingEvent.subscribe(element, ko.bindingEvent.childrenComplete, function () {
5089                        if (!updateFromModelComputed) {
5090                            ko.utils.registerEventHandler(element, "change", updateFromView);
5091                            updateFromModelComputed = ko.computed(updateFromModel, null, { disposeWhenNodeIsRemoved: element });
5092                        } else {
5093                            updateFromView();
5094                        }
5095                    }, null, { 'notifyImmediately': true });
5096                },
5097                'update': function () { } // Keep for backwards compatibility with code that may have wrapped binding
5098            };
5099            ko.expressionRewriting.twoWayBindings['selectedOptions'] = true;
5100            ko.bindingHandlers['style'] = {
5101                'update': function (element, valueAccessor) {
5102                    var value = ko.utils.unwrapObservable(valueAccessor() || {});
5103                    ko.utils.objectForEach(value, function (styleName, styleValue) {
5104                        styleValue = ko.utils.unwrapObservable(styleValue);
5105
5106                        if (styleValue === null || styleValue === undefined || styleValue === false) {
5107                            // Empty string removes the value, whereas null/undefined have no effect
5108                            styleValue = "";
5109                        }
5110
5111                        if (jQueryInstance) {
5112                            jQueryInstance(element)['css'](styleName, styleValue);
5113                        } else if (/^--/.test(styleName)) {
5114                            // Is styleName a custom CSS property?
5115                            element.style.setProperty(styleName, styleValue);
5116                        } else {
5117                            styleName = styleName.replace(/-(\w)/g, function (all, letter) {
5118                                return letter.toUpperCase();
5119                            });
5120
5121                            var previousStyle = element.style[styleName];
5122                            element.style[styleName] = styleValue;
5123
5124                            if (styleValue !== previousStyle && element.style[styleName] == previousStyle && !isNaN(styleValue)) {
5125                                element.style[styleName] = styleValue + "px";
5126                            }
5127                        }
5128                    });
5129                }
5130            };
5131            ko.bindingHandlers['submit'] = {
5132                'init': function (element, valueAccessor, allBindings, viewModel, bindingContext) {
5133                    if (typeof valueAccessor() != "function")
5134                        throw new Error("The value for a submit binding must be a function");
5135                    ko.utils.registerEventHandler(element, "submit", function (event) {
5136                        var handlerReturnValue;
5137                        var value = valueAccessor();
5138                        try { handlerReturnValue = value.call(bindingContext['$data'], element); }
5139                        finally {
5140                            if (handlerReturnValue !== true) { // Normally we want to prevent default action. Developer can override this be explicitly returning true.
5141                                if (event.preventDefault)
5142                                    event.preventDefault();
5143                                else
5144                                    event.returnValue = false;
5145                            }
5146                        }
5147                    });
5148                }
5149            };
5150            ko.bindingHandlers['text'] = {
5151                'init': function () {
5152                    // Prevent binding on the dynamically-injected text node (as developers are unlikely to expect that, and it has security implications).
5153                    // It should also make things faster, as we no longer have to consider whether the text node might be bindable.
5154                    return { 'controlsDescendantBindings': true };
5155                },
5156                'update': function (element, valueAccessor) {
5157                    ko.utils.setTextContent(element, valueAccessor());
5158                }
5159            };
5160            ko.virtualElements.allowedBindings['text'] = true;
5161            (function () {
5162
5163                if (window && window.navigator) {
5164                    var parseVersion = function (matches) {
5165                        if (matches) {
5166                            return parseFloat(matches[1]);
5167                        }
5168                    };
5169
5170                    // Detect various browser versions because some old versions don't fully support the 'input' event
5171                    var userAgent = window.navigator.userAgent,
5172                        operaVersion, chromeVersion, safariVersion, firefoxVersion, ieVersion, edgeVersion;
5173
5174                    (operaVersion = window.opera && window.opera.version && parseInt(window.opera.version()))
5175                        || (edgeVersion = parseVersion(userAgent.match(/Edge\/([^ ]+)$/)))
5176                        || (chromeVersion = parseVersion(userAgent.match(/Chrome\/([^ ]+)/)))
5177                        || (safariVersion = parseVersion(userAgent.match(/Version\/([^ ]+) Safari/)))
5178                        || (firefoxVersion = parseVersion(userAgent.match(/Firefox\/([^ ]+)/)))
5179                        || (ieVersion = ko.utils.ieVersion || parseVersion(userAgent.match(/MSIE ([^ ]+)/)))      // Detects up to IE 10
5180                        || (ieVersion = parseVersion(userAgent.match(/rv:([^ )]+)/)));      // Detects IE 11
5181                }
5182
5183                // IE 8 and 9 have bugs that prevent the normal events from firing when the value changes.
5184                // But it does fire the 'selectionchange' event on many of those, presumably because the
5185                // cursor is moving and that counts as the selection changing. The 'selectionchange' event is
5186                // fired at the document level only and doesn't directly indicate which element changed. We
5187                // set up just one event handler for the document and use 'activeElement' to determine which
5188                // element was changed.
5189                if (ieVersion >= 8 && ieVersion < 10) {
5190                    var selectionChangeRegisteredName = ko.utils.domData.nextKey(),
5191                        selectionChangeHandlerName = ko.utils.domData.nextKey();
5192                    var selectionChangeHandler = function (event) {
5193                        var target = this.activeElement,
5194                            handler = target && ko.utils.domData.get(target, selectionChangeHandlerName);
5195                        if (handler) {
5196                            handler(event);
5197                        }
5198                    };
5199                    var registerForSelectionChangeEvent = function (element, handler) {
5200                        var ownerDoc = element.ownerDocument;
5201                        if (!ko.utils.domData.get(ownerDoc, selectionChangeRegisteredName)) {
5202                            ko.utils.domData.set(ownerDoc, selectionChangeRegisteredName, true);
5203                            ko.utils.registerEventHandler(ownerDoc, 'selectionchange', selectionChangeHandler);
5204                        }
5205                        ko.utils.domData.set(element, selectionChangeHandlerName, handler);
5206                    };
5207                }
5208
5209                ko.bindingHandlers['textInput'] = {
5210                    'init': function (element, valueAccessor, allBindings) {
5211
5212                        var previousElementValue = element.value,
5213                            timeoutHandle,
5214                            elementValueBeforeEvent;
5215
5216                        var updateModel = function (event) {
5217                            clearTimeout(timeoutHandle);
5218                            elementValueBeforeEvent = timeoutHandle = undefined;
5219
5220                            var elementValue = element.value;
5221                            if (previousElementValue !== elementValue) {
5222                                // Provide a way for tests to know exactly which event was processed
5223                                if (DEBUG && event) element['_ko_textInputProcessedEvent'] = event.type;
5224                                previousElementValue = elementValue;
5225                                ko.expressionRewriting.writeValueToProperty(valueAccessor(), allBindings, 'textInput', elementValue);
5226                            }
5227                        };
5228
5229                        var deferUpdateModel = function (event) {
5230                            if (!timeoutHandle) {
5231                                // The elementValueBeforeEvent variable is set *only* during the brief gap between an
5232                                // event firing and the updateModel function running. This allows us to ignore model
5233                                // updates that are from the previous state of the element, usually due to techniques
5234                                // such as rateLimit. Such updates, if not ignored, can cause keystrokes to be lost.
5235                                elementValueBeforeEvent = element.value;
5236                                var handler = DEBUG ? updateModel.bind(element, { type: event.type }) : updateModel;
5237                                timeoutHandle = ko.utils.setTimeout(handler, 4);
5238                            }
5239                        };
5240
5241                        // IE9 will mess up the DOM if you handle events synchronously which results in DOM changes (such as other bindings);
5242                        // so we'll make sure all updates are asynchronous
5243                        var ieUpdateModel = ko.utils.ieVersion == 9 ? deferUpdateModel : updateModel,
5244                            ourUpdate = false;
5245
5246                        var updateView = function () {
5247                            var modelValue = ko.utils.unwrapObservable(valueAccessor());
5248
5249                            if (modelValue === null || modelValue === undefined) {
5250                                modelValue = '';
5251                            }
5252
5253                            if (elementValueBeforeEvent !== undefined && modelValue === elementValueBeforeEvent) {
5254                                ko.utils.setTimeout(updateView, 4);
5255                                return;
5256                            }
5257
5258                            // Update the element only if the element and model are different. On some browsers, updating the value
5259                            // will move the cursor to the end of the input, which would be bad while the user is typing.
5260                            if (element.value !== modelValue) {
5261                                ourUpdate = true;  // Make sure we ignore events (propertychange) that result from updating the value
5262                                element.value = modelValue;
5263                                ourUpdate = false;
5264                                previousElementValue = element.value; // In case the browser changes the value (see #2281)
5265                            }
5266                        };
5267
5268                        var onEvent = function (event, handler) {
5269                            ko.utils.registerEventHandler(element, event, handler);
5270                        };
5271
5272                        if (DEBUG && ko.bindingHandlers['textInput']['_forceUpdateOn']) {
5273                            // Provide a way for tests to specify exactly which events are bound
5274                            ko.utils.arrayForEach(ko.bindingHandlers['textInput']['_forceUpdateOn'], function (eventName) {
5275                                if (eventName.slice(0, 5) == 'after') {
5276                                    onEvent(eventName.slice(5), deferUpdateModel);
5277                                } else {
5278                                    onEvent(eventName, updateModel);
5279                                }
5280                            });
5281                        } else {
5282                            if (ieVersion) {
5283                                // All versions (including 11) of Internet Explorer have a bug that they don't generate an input or propertychange event when ESC is pressed
5284                                onEvent('keypress', updateModel);
5285                            }
5286                            if (ieVersion < 11) {
5287                                // Internet Explorer <= 8 doesn't support the 'input' event, but does include 'propertychange' that fires whenever
5288                                // any property of an element changes. Unlike 'input', it also fires if a property is changed from JavaScript code,
5289                                // but that's an acceptable compromise for this binding. IE 9 and 10 support 'input', but since they don't always
5290                                // fire it when using autocomplete, we'll use 'propertychange' for them also.
5291                                onEvent('propertychange', function (event) {
5292                                    if (!ourUpdate && event.propertyName === 'value') {
5293                                        ieUpdateModel(event);
5294                                    }
5295                                });
5296                            }
5297                            if (ieVersion == 8) {
5298                                // IE 8 has a bug where it fails to fire 'propertychange' on the first update following a value change from
5299                                // JavaScript code. It also doesn't fire if you clear the entire value. To fix this, we bind to the following
5300                                // events too.
5301                                onEvent('keyup', updateModel);      // A single keystoke
5302                                onEvent('keydown', updateModel);    // The first character when a key is held down
5303                            }
5304                            if (registerForSelectionChangeEvent) {
5305                                // Internet Explorer 9 doesn't fire the 'input' event when deleting text, including using
5306                                // the backspace, delete, or ctrl-x keys, clicking the 'x' to clear the input, dragging text
5307                                // out of the field, and cutting or deleting text using the context menu. 'selectionchange'
5308                                // can detect all of those except dragging text out of the field, for which we use 'dragend'.
5309                                // These are also needed in IE8 because of the bug described above.
5310                                registerForSelectionChangeEvent(element, ieUpdateModel);  // 'selectionchange' covers cut, paste, drop, delete, etc.
5311                                onEvent('dragend', deferUpdateModel);
5312                            }
5313
5314                            if (!ieVersion || ieVersion >= 9) {
5315                                // All other supported browsers support the 'input' event, which fires whenever the content of the element is changed
5316                                // through the user interface.
5317                                onEvent('input', ieUpdateModel);
5318                            }
5319
5320                            if (safariVersion < 5 && ko.utils.tagNameLower(element) === "textarea") {
5321                                // Safari <5 doesn't fire the 'input' event for <textarea> elements (it does fire 'textInput'
5322                                // but only when typing). So we'll just catch as much as we can with keydown, cut, and paste.
5323                                onEvent('keydown', deferUpdateModel);
5324                                onEvent('paste', deferUpdateModel);
5325                                onEvent('cut', deferUpdateModel);
5326                            } else if (operaVersion < 11) {
5327                                // Opera 10 doesn't always fire the 'input' event for cut, paste, undo & drop operations.
5328                                // We can try to catch some of those using 'keydown'.
5329                                onEvent('keydown', deferUpdateModel);
5330                            } else if (firefoxVersion < 4.0) {
5331                                // Firefox <= 3.6 doesn't fire the 'input' event when text is filled in through autocomplete
5332                                onEvent('DOMAutoComplete', updateModel);
5333
5334                                // Firefox <=3.5 doesn't fire the 'input' event when text is dropped into the input.
5335                                onEvent('dragdrop', updateModel);       // <3.5
5336                                onEvent('drop', updateModel);           // 3.5
5337                            } else if (edgeVersion && element.type === "number") {
5338                                // Microsoft Edge doesn't fire 'input' or 'change' events for number inputs when
5339                                // the value is changed via the up / down arrow keys
5340                                onEvent('keydown', deferUpdateModel);
5341                            }
5342                        }
5343
5344                        // Bind to the change event so that we can catch programmatic updates of the value that fire this event.
5345                        onEvent('change', updateModel);
5346
5347                        // To deal with browsers that don't notify any kind of event for some changes (IE, Safari, etc.)
5348                        onEvent('blur', updateModel);
5349
5350                        ko.computed(updateView, null, { disposeWhenNodeIsRemoved: element });
5351                    }
5352                };
5353                ko.expressionRewriting.twoWayBindings['textInput'] = true;
5354
5355                // textinput is an alias for textInput
5356                ko.bindingHandlers['textinput'] = {
5357                    // preprocess is the only way to set up a full alias
5358                    'preprocess': function (value, name, addBinding) {
5359                        addBinding('textInput', value);
5360                    }
5361                };
5362
5363            })(); ko.bindingHandlers['uniqueName'] = {
5364                'init': function (element, valueAccessor) {
5365                    if (valueAccessor()) {
5366                        var name = "ko_unique_" + (++ko.bindingHandlers['uniqueName'].currentIndex);
5367                        ko.utils.setElementName(element, name);
5368                    }
5369                }
5370            };
5371            ko.bindingHandlers['uniqueName'].currentIndex = 0;
5372            ko.bindingHandlers['using'] = {
5373                'init': function (element, valueAccessor, allBindings, viewModel, bindingContext) {
5374                    var options;
5375
5376                    if (allBindings['has']('as')) {
5377                        options = { 'as': allBindings.get('as'), 'noChildContext': allBindings.get('noChildContext') };
5378                    }
5379
5380                    var innerContext = bindingContext['createChildContext'](valueAccessor, options);
5381                    ko.applyBindingsToDescendants(innerContext, element);
5382
5383                    return { 'controlsDescendantBindings': true };
5384                }
5385            };
5386            ko.virtualElements.allowedBindings['using'] = true;
5387            ko.bindingHandlers['value'] = {
5388                'init': function (element, valueAccessor, allBindings) {
5389                    var tagName = ko.utils.tagNameLower(element),
5390                        isInputElement = tagName == "input";
5391
5392                    // If the value binding is placed on a radio/checkbox, then just pass through to checkedValue and quit
5393                    if (isInputElement && (element.type == "checkbox" || element.type == "radio")) {
5394                        ko.applyBindingAccessorsToNode(element, { 'checkedValue': valueAccessor });
5395                        return;
5396                    }
5397
5398                    var eventsToCatch = [];
5399                    var requestedEventsToCatch = allBindings.get("valueUpdate");
5400                    var propertyChangedFired = false;
5401                    var elementValueBeforeEvent = null;
5402
5403                    if (requestedEventsToCatch) {
5404                        // Allow both individual event names, and arrays of event names
5405                        if (typeof requestedEventsToCatch == "string") {
5406                            eventsToCatch = [requestedEventsToCatch];
5407                        } else {
5408                            eventsToCatch = ko.utils.arrayGetDistinctValues(requestedEventsToCatch);
5409                        }
5410                        ko.utils.arrayRemoveItem(eventsToCatch, "change");  // We'll subscribe to "change" events later
5411                    }
5412
5413                    var valueUpdateHandler = function () {
5414                        elementValueBeforeEvent = null;
5415                        propertyChangedFired = false;
5416                        var modelValue = valueAccessor();
5417                        var elementValue = ko.selectExtensions.readValue(element);
5418                        ko.expressionRewriting.writeValueToProperty(modelValue, allBindings, 'value', elementValue);
5419                    }
5420
5421                    // Workaround for https://github.com/SteveSanderson/knockout/issues/122
5422                    // IE doesn't fire "change" events on textboxes if the user selects a value from its autocomplete list
5423                    var ieAutoCompleteHackNeeded = ko.utils.ieVersion && isInputElement && element.type == "text"
5424                        && element.autocomplete != "off" && (!element.form || element.form.autocomplete != "off");
5425                    if (ieAutoCompleteHackNeeded && ko.utils.arrayIndexOf(eventsToCatch, "propertychange") == -1) {
5426                        ko.utils.registerEventHandler(element, "propertychange", function () { propertyChangedFired = true });
5427                        ko.utils.registerEventHandler(element, "focus", function () { propertyChangedFired = false });
5428                        ko.utils.registerEventHandler(element, "blur", function () {
5429                            if (propertyChangedFired) {
5430                                valueUpdateHandler();
5431                            }
5432                        });
5433                    }
5434
5435                    ko.utils.arrayForEach(eventsToCatch, function (eventName) {
5436                        // The syntax "after<eventname>" means "run the handler asynchronously after the event"
5437                        // This is useful, for example, to catch "keydown" events after the browser has updated the control
5438                        // (otherwise, ko.selectExtensions.readValue(this) will receive the control's value *before* the key event)
5439                        var handler = valueUpdateHandler;
5440                        if (ko.utils.stringStartsWith(eventName, "after")) {
5441                            handler = function () {
5442                                // The elementValueBeforeEvent variable is non-null *only* during the brief gap between
5443                                // a keyX event firing and the valueUpdateHandler running, which is scheduled to happen
5444                                // at the earliest asynchronous opportunity. We store this temporary information so that
5445                                // if, between keyX and valueUpdateHandler, the underlying model value changes separately,
5446                                // we can overwrite that model value change with the value the user just typed. Otherwise,
5447                                // techniques like rateLimit can trigger model changes at critical moments that will
5448                                // override the user's inputs, causing keystrokes to be lost.
5449                                elementValueBeforeEvent = ko.selectExtensions.readValue(element);
5450                                ko.utils.setTimeout(valueUpdateHandler, 0);
5451                            };
5452                            eventName = eventName.substring("after".length);
5453                        }
5454                        ko.utils.registerEventHandler(element, eventName, handler);
5455                    });
5456
5457                    var updateFromModel;
5458
5459                    if (isInputElement && element.type == "file") {
5460                        // For file input elements, can only write the empty string
5461                        updateFromModel = function () {
5462                            var newValue = ko.utils.unwrapObservable(valueAccessor());
5463                            if (newValue === null || newValue === undefined || newValue === "") {
5464                                element.value = "";
5465                            } else {
5466                                ko.dependencyDetection.ignore(valueUpdateHandler);  // reset the model to match the element
5467                            }
5468                        }
5469                    } else {
5470                        updateFromModel = function () {
5471                            var newValue = ko.utils.unwrapObservable(valueAccessor());
5472                            var elementValue = ko.selectExtensions.readValue(element);
5473
5474                            if (elementValueBeforeEvent !== null && newValue === elementValueBeforeEvent) {
5475                                ko.utils.setTimeout(updateFromModel, 0);
5476                                return;
5477                            }
5478
5479                            var valueHasChanged = newValue !== elementValue;
5480
5481                            if (valueHasChanged || elementValue === undefined) {
5482                                if (tagName === "select") {
5483                                    var allowUnset = allBindings.get('valueAllowUnset');
5484                                    ko.selectExtensions.writeValue(element, newValue, allowUnset);
5485                                    if (!allowUnset && newValue !== ko.selectExtensions.readValue(element)) {
5486                                        // If you try to set a model value that can't be represented in an already-populated dropdown, reject that change,
5487                                        // because you're not allowed to have a model value that disagrees with a visible UI selection.
5488                                        ko.dependencyDetection.ignore(valueUpdateHandler);
5489                                    }
5490                                } else {
5491                                    ko.selectExtensions.writeValue(element, newValue);
5492                                }
5493                            }
5494                        };
5495                    }
5496
5497                    if (tagName === "select") {
5498                        var updateFromModelComputed;
5499                        ko.bindingEvent.subscribe(element, ko.bindingEvent.childrenComplete, function () {
5500                            if (!updateFromModelComputed) {
5501                                ko.utils.registerEventHandler(element, "change", valueUpdateHandler);
5502                                updateFromModelComputed = ko.computed(updateFromModel, null, { disposeWhenNodeIsRemoved: element });
5503                            } else if (allBindings.get('valueAllowUnset')) {
5504                                updateFromModel();
5505                            } else {
5506                                valueUpdateHandler();
5507                            }
5508                        }, null, { 'notifyImmediately': true });
5509                    } else {
5510                        ko.utils.registerEventHandler(element, "change", valueUpdateHandler);
5511                        ko.computed(updateFromModel, null, { disposeWhenNodeIsRemoved: element });
5512                    }
5513                },
5514                'update': function () { } // Keep for backwards compatibility with code that may have wrapped value binding
5515            };
5516            ko.expressionRewriting.twoWayBindings['value'] = true;
5517            ko.bindingHandlers['visible'] = {
5518                'update': function (element, valueAccessor) {
5519                    var value = ko.utils.unwrapObservable(valueAccessor());
5520                    var isCurrentlyVisible = !(element.style.display == "none");
5521                    if (value && !isCurrentlyVisible)
5522                        element.style.display = "";
5523                    else if ((!value) && isCurrentlyVisible)
5524                        element.style.display = "none";
5525                }
5526            };
5527
5528            ko.bindingHandlers['hidden'] = {
5529                'update': function (element, valueAccessor) {
5530                    ko.bindingHandlers['visible']['update'](element, function () { return !ko.utils.unwrapObservable(valueAccessor()) });
5531                }
5532            };
5533            // 'click' is just a shorthand for the usual full-length event:{click:handler}
5534            makeEventHandlerShortcut('click');
5535            // If you want to make a custom template engine,
5536            //
5537            // [1] Inherit from this class (like ko.nativeTemplateEngine does)
5538            // [2] Override 'renderTemplateSource', supplying a function with this signature:
5539            //
5540            //        function (templateSource, bindingContext, options) {
5541            //            // - templateSource.text() is the text of the template you should render
5542            //            // - bindingContext.$data is the data you should pass into the template
5543            //            //   - you might also want to make bindingContext.$parent, bindingContext.$parents,
5544            //            //     and bindingContext.$root available in the template too
5545            //            // - options gives you access to any other properties set on "data-bind: { template: options }"
5546            //            // - templateDocument is the document object of the template
5547            //            //
5548            //            // Return value: an array of DOM nodes
5549            //        }
5550            //
5551            // [3] Override 'createJavaScriptEvaluatorBlock', supplying a function with this signature:
5552            //
5553            //        function (script) {
5554            //            // Return value: Whatever syntax means "Evaluate the JavaScript statement 'script' and output the result"
5555            //            //               For example, the jquery.tmpl template engine converts 'someScript' to '${ someScript }'
5556            //        }
5557            //
5558            //     This is only necessary if you want to allow data-bind attributes to reference arbitrary template variables.
5559            //     If you don't want to allow that, you can set the property 'allowTemplateRewriting' to false (like ko.nativeTemplateEngine does)
5560            //     and then you don't need to override 'createJavaScriptEvaluatorBlock'.
5561
5562            ko.templateEngine = function () { };
5563
5564            ko.templateEngine.prototype['renderTemplateSource'] = function (templateSource, bindingContext, options, templateDocument) {
5565                throw new Error("Override renderTemplateSource");
5566            };
5567
5568            ko.templateEngine.prototype['createJavaScriptEvaluatorBlock'] = function (script) {
5569                throw new Error("Override createJavaScriptEvaluatorBlock");
5570            };
5571
5572            ko.templateEngine.prototype['makeTemplateSource'] = function (template, templateDocument) {
5573                // Named template
5574                if (typeof template == "string") {
5575                    templateDocument = templateDocument || document;
5576                    var elem = templateDocument.getElementById(template);
5577                    if (!elem)
5578                        throw new Error("Cannot find template with ID " + template);
5579                    return new ko.templateSources.domElement(elem);
5580                } else if ((template.nodeType == 1) || (template.nodeType == 8)) {
5581                    // Anonymous template
5582                    return new ko.templateSources.anonymousTemplate(template);
5583                } else
5584                    throw new Error("Unknown template type: " + template);
5585            };
5586
5587            ko.templateEngine.prototype['renderTemplate'] = function (template, bindingContext, options, templateDocument) {
5588                var templateSource = this['makeTemplateSource'](template, templateDocument);
5589                return this['renderTemplateSource'](templateSource, bindingContext, options, templateDocument);
5590            };
5591
5592            ko.templateEngine.prototype['isTemplateRewritten'] = function (template, templateDocument) {
5593                // Skip rewriting if requested
5594                if (this['allowTemplateRewriting'] === false)
5595                    return true;
5596                return this['makeTemplateSource'](template, templateDocument)['data']("isRewritten");
5597            };
5598
5599            ko.templateEngine.prototype['rewriteTemplate'] = function (template, rewriterCallback, templateDocument) {
5600                var templateSource = this['makeTemplateSource'](template, templateDocument);
5601                var rewritten = rewriterCallback(templateSource['text']());
5602                templateSource['text'](rewritten);
5603                templateSource['data']("isRewritten", true);
5604            };
5605
5606            ko.exportSymbol('templateEngine', ko.templateEngine);
5607
5608            ko.templateRewriting = (function () {
5609                var memoizeDataBindingAttributeSyntaxRegex = /(<([a-z]+\d*)(?:\s+(?!data-bind\s*=\s*)[a-z0-9\-]+(?:=(?:\"[^\"]*\"|\'[^\']*\'|[^>]*))?)*\s+)data-bind\s*=\s*(["'])([\s\S]*?)\3/gi;
5610                var memoizeVirtualContainerBindingSyntaxRegex = /<!--\s*ko\b\s*([\s\S]*?)\s*-->/g;
5611
5612                function validateDataBindValuesForRewriting(keyValueArray) {
5613                    var allValidators = ko.expressionRewriting.bindingRewriteValidators;
5614                    for (var i = 0; i < keyValueArray.length; i++) {
5615                        var key = keyValueArray[i]['key'];
5616                        if (Object.prototype.hasOwnProperty.call(allValidators, key)) {
5617                            var validator = allValidators[key];
5618
5619                            if (typeof validator === "function") {
5620                                var possibleErrorMessage = validator(keyValueArray[i]['value']);
5621                                if (possibleErrorMessage)
5622                                    throw new Error(possibleErrorMessage);
5623                            } else if (!validator) {
5624                                throw new Error("This template engine does not support the '" + key + "' binding within its templates");
5625                            }
5626                        }
5627                    }
5628                }
5629
5630                function constructMemoizedTagReplacement(dataBindAttributeValue, tagToRetain, nodeName, templateEngine) {
5631                    var dataBindKeyValueArray = ko.expressionRewriting.parseObjectLiteral(dataBindAttributeValue);
5632                    validateDataBindValuesForRewriting(dataBindKeyValueArray);
5633                    var rewrittenDataBindAttributeValue = ko.expressionRewriting.preProcessBindings(dataBindKeyValueArray, { 'valueAccessors': true });
5634
5635                    // For no obvious reason, Opera fails to evaluate rewrittenDataBindAttributeValue unless it's wrapped in an additional
5636                    // anonymous function, even though Opera's built-in debugger can evaluate it anyway. No other browser requires this
5637                    // extra indirection.
5638                    var applyBindingsToNextSiblingScript =
5639                        "ko.__tr_ambtns(function($context,$element){return(function(){return{ " + rewrittenDataBindAttributeValue + " } })()},'" + nodeName.toLowerCase() + "')";
5640                    return templateEngine['createJavaScriptEvaluatorBlock'](applyBindingsToNextSiblingScript) + tagToRetain;
5641                }
5642
5643                return {
5644                    ensureTemplateIsRewritten: function (template, templateEngine, templateDocument) {
5645                        if (!templateEngine['isTemplateRewritten'](template, templateDocument))
5646                            templateEngine['rewriteTemplate'](template, function (htmlString) {
5647                                return ko.templateRewriting.memoizeBindingAttributeSyntax(htmlString, templateEngine);
5648                            }, templateDocument);
5649                    },
5650
5651                    memoizeBindingAttributeSyntax: function (htmlString, templateEngine) {
5652                        return htmlString.replace(memoizeDataBindingAttributeSyntaxRegex, function () {
5653                            return constructMemoizedTagReplacement(/* dataBindAttributeValue: */ arguments[4], /* tagToRetain: */ arguments[1], /* nodeName: */ arguments[2], templateEngine);
5654                        }).replace(memoizeVirtualContainerBindingSyntaxRegex, function () {
5655                            return constructMemoizedTagReplacement(/* dataBindAttributeValue: */ arguments[1], /* tagToRetain: */ "<!-- ko -->", /* nodeName: */ "#comment", templateEngine);
5656                        });
5657                    },
5658
5659                    applyMemoizedBindingsToNextSibling: function (bindings, nodeName) {
5660                        return ko.memoization.memoize(function (domNode, bindingContext) {
5661                            var nodeToBind = domNode.nextSibling;
5662                            if (nodeToBind && nodeToBind.nodeName.toLowerCase() === nodeName) {
5663                                ko.applyBindingAccessorsToNode(nodeToBind, bindings, bindingContext);
5664                            }
5665                        });
5666                    }
5667                }
5668            })();
5669
5670
5671            // Exported only because it has to be referenced by string lookup from within rewritten template
5672            ko.exportSymbol('__tr_ambtns', ko.templateRewriting.applyMemoizedBindingsToNextSibling);
5673            (function () {
5674                // A template source represents a read/write way of accessing a template. This is to eliminate the need for template loading/saving
5675                // logic to be duplicated in every template engine (and means they can all work with anonymous templates, etc.)
5676                //
5677                // Two are provided by default:
5678                //  1. ko.templateSources.domElement       - reads/writes the text content of an arbitrary DOM element
5679                //  2. ko.templateSources.anonymousElement - uses ko.utils.domData to read/write text *associated* with the DOM element, but
5680                //                                           without reading/writing the actual element text content, since it will be overwritten
5681                //                                           with the rendered template output.
5682                // You can implement your own template source if you want to fetch/store templates somewhere other than in DOM elements.
5683                // Template sources need to have the following functions:
5684                //   text() 			- returns the template text from your storage location
5685                //   text(value)		- writes the supplied template text to your storage location
5686                //   data(key)			- reads values stored using data(key, value) - see below
5687                //   data(key, value)	- associates "value" with this template and the key "key". Is used to store information like "isRewritten".
5688                //
5689                // Optionally, template sources can also have the following functions:
5690                //   nodes()            - returns a DOM element containing the nodes of this template, where available
5691                //   nodes(value)       - writes the given DOM element to your storage location
5692                // If a DOM element is available for a given template source, template engines are encouraged to use it in preference over text()
5693                // for improved speed. However, all templateSources must supply text() even if they don't supply nodes().
5694                //
5695                // Once you've implemented a templateSource, make your template engine use it by subclassing whatever template engine you were
5696                // using and overriding "makeTemplateSource" to return an instance of your custom template source.
5697
5698                ko.templateSources = {};
5699
5700                // ---- ko.templateSources.domElement -----
5701
5702                // template types
5703                var templateScript = 1,
5704                    templateTextArea = 2,
5705                    templateTemplate = 3,
5706                    templateElement = 4;
5707
5708                ko.templateSources.domElement = function (element) {
5709                    this.domElement = element;
5710
5711                    if (element) {
5712                        var tagNameLower = ko.utils.tagNameLower(element);
5713                        this.templateType =
5714                            tagNameLower === "script" ? templateScript :
5715                                tagNameLower === "textarea" ? templateTextArea :
5716                                    // For browsers with proper <template> element support, where the .content property gives a document fragment
5717                                    tagNameLower == "template" && element.content && element.content.nodeType === 11 ? templateTemplate :
5718                                        templateElement;
5719                    }
5720                }
5721
5722                ko.templateSources.domElement.prototype['text'] = function (/* valueToWrite */) {
5723                    var elemContentsProperty = this.templateType === templateScript ? "text"
5724                        : this.templateType === templateTextArea ? "value"
5725                            : "innerHTML";
5726
5727                    if (arguments.length == 0) {
5728                        return this.domElement[elemContentsProperty];
5729                    } else {
5730                        var valueToWrite = arguments[0];
5731                        if (elemContentsProperty === "innerHTML")
5732                            ko.utils.setHtml(this.domElement, valueToWrite);
5733                        else
5734                            this.domElement[elemContentsProperty] = valueToWrite;
5735                    }
5736                };
5737
5738                var dataDomDataPrefix = ko.utils.domData.nextKey() + "_";
5739                ko.templateSources.domElement.prototype['data'] = function (key /*, valueToWrite */) {
5740                    if (arguments.length === 1) {
5741                        return ko.utils.domData.get(this.domElement, dataDomDataPrefix + key);
5742                    } else {
5743                        ko.utils.domData.set(this.domElement, dataDomDataPrefix + key, arguments[1]);
5744                    }
5745                };
5746
5747                var templatesDomDataKey = ko.utils.domData.nextKey();
5748                function getTemplateDomData(element) {
5749                    return ko.utils.domData.get(element, templatesDomDataKey) || {};
5750                }
5751                function setTemplateDomData(element, data) {
5752                    ko.utils.domData.set(element, templatesDomDataKey, data);
5753                }
5754
5755                ko.templateSources.domElement.prototype['nodes'] = function (/* valueToWrite */) {
5756                    var element = this.domElement;
5757                    if (arguments.length == 0) {
5758                        var templateData = getTemplateDomData(element),
5759                            nodes = templateData.containerData || (
5760                                this.templateType === templateTemplate ? element.content :
5761                                    this.templateType === templateElement ? element :
5762                                        undefined);
5763                        if (!nodes || templateData.alwaysCheckText) {
5764                            // If the template is associated with an element that stores the template as text,
5765                            // parse and cache the nodes whenever there's new text content available. This allows
5766                            // the user to update the template content by updating the text of template node.
5767                            var text = this['text']();
5768                            if (text && text !== templateData.textData) {
5769                                nodes = ko.utils.parseHtmlForTemplateNodes(text, element.ownerDocument);
5770                                setTemplateDomData(element, { containerData: nodes, textData: text, alwaysCheckText: true });
5771                            }
5772                        }
5773                        return nodes;
5774                    } else {
5775                        var valueToWrite = arguments[0];
5776                        if (this.templateType !== undefined) {
5777                            this['text']("");   // clear the text from the node
5778                        }
5779                        setTemplateDomData(element, { containerData: valueToWrite });
5780                    }
5781                };
5782
5783                // ---- ko.templateSources.anonymousTemplate -----
5784                // Anonymous templates are normally saved/retrieved as DOM nodes through "nodes".
5785                // For compatibility, you can also read "text"; it will be serialized from the nodes on demand.
5786                // Writing to "text" is still supported, but then the template data will not be available as DOM nodes.
5787
5788                ko.templateSources.anonymousTemplate = function (element) {
5789                    this.domElement = element;
5790                }
5791                ko.templateSources.anonymousTemplate.prototype = new ko.templateSources.domElement();
5792                ko.templateSources.anonymousTemplate.prototype.constructor = ko.templateSources.anonymousTemplate;
5793                ko.templateSources.anonymousTemplate.prototype['text'] = function (/* valueToWrite */) {
5794                    if (arguments.length == 0) {
5795                        var templateData = getTemplateDomData(this.domElement);
5796                        if (templateData.textData === undefined && templateData.containerData)
5797                            templateData.textData = templateData.containerData.innerHTML;
5798                        return templateData.textData;
5799                    } else {
5800                        var valueToWrite = arguments[0];
5801                        setTemplateDomData(this.domElement, { textData: valueToWrite });
5802                    }
5803                };
5804
5805                ko.exportSymbol('templateSources', ko.templateSources);
5806                ko.exportSymbol('templateSources.domElement', ko.templateSources.domElement);
5807                ko.exportSymbol('templateSources.anonymousTemplate', ko.templateSources.anonymousTemplate);
5808            })();
5809            (function () {
5810                var _templateEngine;
5811                ko.setTemplateEngine = function (templateEngine) {
5812                    if ((templateEngine != undefined) && !(templateEngine instanceof ko.templateEngine))
5813                        throw new Error("templateEngine must inherit from ko.templateEngine");
5814                    _templateEngine = templateEngine;
5815                }
5816
5817                function invokeForEachNodeInContinuousRange(firstNode, lastNode, action) {
5818                    var node, nextInQueue = firstNode, firstOutOfRangeNode = ko.virtualElements.nextSibling(lastNode);
5819                    while (nextInQueue && ((node = nextInQueue) !== firstOutOfRangeNode)) {
5820                        nextInQueue = ko.virtualElements.nextSibling(node);
5821                        action(node, nextInQueue);
5822                    }
5823                }
5824
5825                function activateBindingsOnContinuousNodeArray(continuousNodeArray, bindingContext) {
5826                    // To be used on any nodes that have been rendered by a template and have been inserted into some parent element
5827                    // Walks through continuousNodeArray (which *must* be continuous, i.e., an uninterrupted sequence of sibling nodes, because
5828                    // the algorithm for walking them relies on this), and for each top-level item in the virtual-element sense,
5829                    // (1) Does a regular "applyBindings" to associate bindingContext with this node and to activate any non-memoized bindings
5830                    // (2) Unmemoizes any memos in the DOM subtree (e.g., to activate bindings that had been memoized during template rewriting)
5831
5832                    if (continuousNodeArray.length) {
5833                        var firstNode = continuousNodeArray[0],
5834                            lastNode = continuousNodeArray[continuousNodeArray.length - 1],
5835                            parentNode = firstNode.parentNode,
5836                            provider = ko.bindingProvider['instance'],
5837                            preprocessNode = provider['preprocessNode'];
5838
5839                        if (preprocessNode) {
5840                            invokeForEachNodeInContinuousRange(firstNode, lastNode, function (node, nextNodeInRange) {
5841                                var nodePreviousSibling = node.previousSibling;
5842                                var newNodes = preprocessNode.call(provider, node);
5843                                if (newNodes) {
5844                                    if (node === firstNode)
5845                                        firstNode = newNodes[0] || nextNodeInRange;
5846                                    if (node === lastNode)
5847                                        lastNode = newNodes[newNodes.length - 1] || nodePreviousSibling;
5848                                }
5849                            });
5850
5851                            // Because preprocessNode can change the nodes, including the first and last nodes, update continuousNodeArray to match.
5852                            // We need the full set, including inner nodes, because the unmemoize step might remove the first node (and so the real
5853                            // first node needs to be in the array).
5854                            continuousNodeArray.length = 0;
5855                            if (!firstNode) { // preprocessNode might have removed all the nodes, in which case there's nothing left to do
5856                                return;
5857                            }
5858                            if (firstNode === lastNode) {
5859                                continuousNodeArray.push(firstNode);
5860                            } else {
5861                                continuousNodeArray.push(firstNode, lastNode);
5862                                ko.utils.fixUpContinuousNodeArray(continuousNodeArray, parentNode);
5863                            }
5864                        }
5865
5866                        // Need to applyBindings *before* unmemoziation, because unmemoization might introduce extra nodes (that we don't want to re-bind)
5867                        // whereas a regular applyBindings won't introduce new memoized nodes
5868                        invokeForEachNodeInContinuousRange(firstNode, lastNode, function (node) {
5869                            if (node.nodeType === 1 || node.nodeType === 8)
5870                                ko.applyBindings(bindingContext, node);
5871                        });
5872                        invokeForEachNodeInContinuousRange(firstNode, lastNode, function (node) {
5873                            if (node.nodeType === 1 || node.nodeType === 8)
5874                                ko.memoization.unmemoizeDomNodeAndDescendants(node, [bindingContext]);
5875                        });
5876
5877                        // Make sure any changes done by applyBindings or unmemoize are reflected in the array
5878                        ko.utils.fixUpContinuousNodeArray(continuousNodeArray, parentNode);
5879                    }
5880                }
5881
5882                function getFirstNodeFromPossibleArray(nodeOrNodeArray) {
5883                    return nodeOrNodeArray.nodeType ? nodeOrNodeArray
5884                        : nodeOrNodeArray.length > 0 ? nodeOrNodeArray[0]
5885                            : null;
5886                }
5887
5888                function executeTemplate(targetNodeOrNodeArray, renderMode, template, bindingContext, options) {
5889                    options = options || {};
5890                    var firstTargetNode = targetNodeOrNodeArray && getFirstNodeFromPossibleArray(targetNodeOrNodeArray);
5891                    var templateDocument = (firstTargetNode || template || {}).ownerDocument;
5892                    var templateEngineToUse = (options['templateEngine'] || _templateEngine);
5893                    ko.templateRewriting.ensureTemplateIsRewritten(template, templateEngineToUse, templateDocument);
5894                    var renderedNodesArray = templateEngineToUse['renderTemplate'](template, bindingContext, options, templateDocument);
5895
5896                    // Loosely check result is an array of DOM nodes
5897                    if ((typeof renderedNodesArray.length != "number") || (renderedNodesArray.length > 0 && typeof renderedNodesArray[0].nodeType != "number"))
5898                        throw new Error("Template engine must return an array of DOM nodes");
5899
5900                    var haveAddedNodesToParent = false;
5901                    switch (renderMode) {
5902                        case "replaceChildren":
5903                            ko.virtualElements.setDomNodeChildren(targetNodeOrNodeArray, renderedNodesArray);
5904                            haveAddedNodesToParent = true;
5905                            break;
5906                        case "replaceNode":
5907                            ko.utils.replaceDomNodes(targetNodeOrNodeArray, renderedNodesArray);
5908                            haveAddedNodesToParent = true;
5909                            break;
5910                        case "ignoreTargetNode": break;
5911                        default:
5912                            throw new Error("Unknown renderMode: " + renderMode);
5913                    }
5914
5915                    if (haveAddedNodesToParent) {
5916                        activateBindingsOnContinuousNodeArray(renderedNodesArray, bindingContext);
5917                        if (options['afterRender']) {
5918                            ko.dependencyDetection.ignore(options['afterRender'], null, [renderedNodesArray, bindingContext[options['as'] || '$data']]);
5919                        }
5920                        if (renderMode == "replaceChildren") {
5921                            ko.bindingEvent.notify(targetNodeOrNodeArray, ko.bindingEvent.childrenComplete);
5922                        }
5923                    }
5924
5925                    return renderedNodesArray;
5926                }
5927
5928                function resolveTemplateName(template, data, context) {
5929                    // The template can be specified as:
5930                    if (ko.isObservable(template)) {
5931                        // 1. An observable, with string value
5932                        return template();
5933                    } else if (typeof template === 'function') {
5934                        // 2. A function of (data, context) returning a string
5935                        return template(data, context);
5936                    } else {
5937                        // 3. A string
5938                        return template;
5939                    }
5940                }
5941
5942                ko.renderTemplate = function (template, dataOrBindingContext, options, targetNodeOrNodeArray, renderMode) {
5943                    options = options || {};
5944                    if ((options['templateEngine'] || _templateEngine) == undefined)
5945                        throw new Error("Set a template engine before calling renderTemplate");
5946                    renderMode = renderMode || "replaceChildren";
5947
5948                    if (targetNodeOrNodeArray) {
5949                        var firstTargetNode = getFirstNodeFromPossibleArray(targetNodeOrNodeArray);
5950
5951                        var whenToDispose = function () { return (!firstTargetNode) || !ko.utils.domNodeIsAttachedToDocument(firstTargetNode); }; // Passive disposal (on next evaluation)
5952                        var activelyDisposeWhenNodeIsRemoved = (firstTargetNode && renderMode == "replaceNode") ? firstTargetNode.parentNode : firstTargetNode;
5953
5954                        return ko.dependentObservable( // So the DOM is automatically updated when any dependency changes
5955                            function () {
5956                                // Ensure we've got a proper binding context to work with
5957                                var bindingContext = (dataOrBindingContext && (dataOrBindingContext instanceof ko.bindingContext))
5958                                    ? dataOrBindingContext
5959                                    : new ko.bindingContext(dataOrBindingContext, null, null, null, { "exportDependencies": true });
5960
5961                                var templateName = resolveTemplateName(template, bindingContext['$data'], bindingContext),
5962                                    renderedNodesArray = executeTemplate(targetNodeOrNodeArray, renderMode, templateName, bindingContext, options);
5963
5964                                if (renderMode == "replaceNode") {
5965                                    targetNodeOrNodeArray = renderedNodesArray;
5966                                    firstTargetNode = getFirstNodeFromPossibleArray(targetNodeOrNodeArray);
5967                                }
5968                            },
5969                            null,
5970                            { disposeWhen: whenToDispose, disposeWhenNodeIsRemoved: activelyDisposeWhenNodeIsRemoved }
5971                        );
5972                    } else {
5973                        // We don't yet have a DOM node to evaluate, so use a memo and render the template later when there is a DOM node
5974                        return ko.memoization.memoize(function (domNode) {
5975                            ko.renderTemplate(template, dataOrBindingContext, options, domNode, "replaceNode");
5976                        });
5977                    }
5978                };
5979
5980                ko.renderTemplateForEach = function (template, arrayOrObservableArray, options, targetNode, parentBindingContext) {
5981                    // Since setDomNodeChildrenFromArrayMapping always calls executeTemplateForArrayItem and then
5982                    // activateBindingsCallback for added items, we can store the binding context in the former to use in the latter.
5983                    var arrayItemContext, asName = options['as'];
5984
5985                    // This will be called by setDomNodeChildrenFromArrayMapping to get the nodes to add to targetNode
5986                    var executeTemplateForArrayItem = function (arrayValue, index) {
5987                        // Support selecting template as a function of the data being rendered
5988                        arrayItemContext = parentBindingContext['createChildContext'](arrayValue, {
5989                            'as': asName,
5990                            'noChildContext': options['noChildContext'],
5991                            'extend': function (context) {
5992                                context['$index'] = index;
5993                                if (asName) {
5994                                    context[asName + "Index"] = index;
5995                                }
5996                            }
5997                        });
5998
5999                        var templateName = resolveTemplateName(template, arrayValue, arrayItemContext);
6000                        return executeTemplate(targetNode, "ignoreTargetNode", templateName, arrayItemContext, options);
6001                    };
6002
6003                    // This will be called whenever setDomNodeChildrenFromArrayMapping has added nodes to targetNode
6004                    var activateBindingsCallback = function (arrayValue, addedNodesArray, index) {
6005                        activateBindingsOnContinuousNodeArray(addedNodesArray, arrayItemContext);
6006                        if (options['afterRender'])
6007                            options['afterRender'](addedNodesArray, arrayValue);
6008
6009                        // release the "cache" variable, so that it can be collected by
6010                        // the GC when its value isn't used from within the bindings anymore.
6011                        arrayItemContext = null;
6012                    };
6013
6014                    var setDomNodeChildrenFromArrayMapping = function (newArray, changeList) {
6015                        // Call setDomNodeChildrenFromArrayMapping, ignoring any observables unwrapped within (most likely from a callback function).
6016                        // If the array items are observables, though, they will be unwrapped in executeTemplateForArrayItem and managed within setDomNodeChildrenFromArrayMapping.
6017                        ko.dependencyDetection.ignore(ko.utils.setDomNodeChildrenFromArrayMapping, null, [targetNode, newArray, executeTemplateForArrayItem, options, activateBindingsCallback, changeList]);
6018                        ko.bindingEvent.notify(targetNode, ko.bindingEvent.childrenComplete);
6019                    };
6020
6021                    var shouldHideDestroyed = (options['includeDestroyed'] === false) || (ko.options['foreachHidesDestroyed'] && !options['includeDestroyed']);
6022
6023                    if (!shouldHideDestroyed && !options['beforeRemove'] && ko.isObservableArray(arrayOrObservableArray)) {
6024                        setDomNodeChildrenFromArrayMapping(arrayOrObservableArray.peek());
6025
6026                        var subscription = arrayOrObservableArray.subscribe(function (changeList) {
6027                            setDomNodeChildrenFromArrayMapping(arrayOrObservableArray(), changeList);
6028                        }, null, "arrayChange");
6029                        subscription.disposeWhenNodeIsRemoved(targetNode);
6030
6031                        return subscription;
6032                    } else {
6033                        return ko.dependentObservable(function () {
6034                            var unwrappedArray = ko.utils.unwrapObservable(arrayOrObservableArray) || [];
6035                            if (typeof unwrappedArray.length == "undefined") // Coerce single value into array
6036                                unwrappedArray = [unwrappedArray];
6037
6038                            if (shouldHideDestroyed) {
6039                                // Filter out any entries marked as destroyed
6040                                unwrappedArray = ko.utils.arrayFilter(unwrappedArray, function (item) {
6041                                    return item === undefined || item === null || !ko.utils.unwrapObservable(item['_destroy']);
6042                                });
6043                            }
6044                            setDomNodeChildrenFromArrayMapping(unwrappedArray);
6045
6046                        }, null, { disposeWhenNodeIsRemoved: targetNode });
6047                    }
6048                };
6049
6050                var templateComputedDomDataKey = ko.utils.domData.nextKey();
6051                function disposeOldComputedAndStoreNewOne(element, newComputed) {
6052                    var oldComputed = ko.utils.domData.get(element, templateComputedDomDataKey);
6053                    if (oldComputed && (typeof (oldComputed.dispose) == 'function'))
6054                        oldComputed.dispose();
6055                    ko.utils.domData.set(element, templateComputedDomDataKey, (newComputed && (!newComputed.isActive || newComputed.isActive())) ? newComputed : undefined);
6056                }
6057
6058                var cleanContainerDomDataKey = ko.utils.domData.nextKey();
6059                ko.bindingHandlers['template'] = {
6060                    'init': function (element, valueAccessor) {
6061                        // Support anonymous templates
6062                        var bindingValue = ko.utils.unwrapObservable(valueAccessor());
6063                        if (typeof bindingValue == "string" || 'name' in bindingValue) {
6064                            // It's a named template - clear the element
6065                            ko.virtualElements.emptyNode(element);
6066                        } else if ('nodes' in bindingValue) {
6067                            // We've been given an array of DOM nodes. Save them as the template source.
6068                            // There is no known use case for the node array being an observable array (if the output
6069                            // varies, put that behavior *into* your template - that's what templates are for), and
6070                            // the implementation would be a mess, so assert that it's not observable.
6071                            var nodes = bindingValue['nodes'] || [];
6072                            if (ko.isObservable(nodes)) {
6073                                throw new Error('The "nodes" option must be a plain, non-observable array.');
6074                            }
6075
6076                            // If the nodes are already attached to a KO-generated container, we reuse that container without moving the
6077                            // elements to a new one (we check only the first node, as the nodes are always moved together)
6078                            var container = nodes[0] && nodes[0].parentNode;
6079                            if (!container || !ko.utils.domData.get(container, cleanContainerDomDataKey)) {
6080                                container = ko.utils.moveCleanedNodesToContainerElement(nodes);
6081                                ko.utils.domData.set(container, cleanContainerDomDataKey, true);
6082                            }
6083
6084                            new ko.templateSources.anonymousTemplate(element)['nodes'](container);
6085                        } else {
6086                            // It's an anonymous template - store the element contents, then clear the element
6087                            var templateNodes = ko.virtualElements.childNodes(element);
6088                            if (templateNodes.length > 0) {
6089                                var container = ko.utils.moveCleanedNodesToContainerElement(templateNodes); // This also removes the nodes from their current parent
6090                                new ko.templateSources.anonymousTemplate(element)['nodes'](container);
6091                            } else {
6092                                throw new Error("Anonymous template defined, but no template content was provided");
6093                            }
6094                        }
6095                        return { 'controlsDescendantBindings': true };
6096                    },
6097                    'update': function (element, valueAccessor, allBindings, viewModel, bindingContext) {
6098                        var value = valueAccessor(),
6099                            options = ko.utils.unwrapObservable(value),
6100                            shouldDisplay = true,
6101                            templateComputed = null,
6102                            template;
6103
6104                        if (typeof options == "string") {
6105                            template = value;
6106                            options = {};
6107                        } else {
6108                            template = 'name' in options ? options['name'] : element;
6109
6110                            // Support "if"/"ifnot" conditions
6111                            if ('if' in options)
6112                                shouldDisplay = ko.utils.unwrapObservable(options['if']);
6113                            if (shouldDisplay && 'ifnot' in options)
6114                                shouldDisplay = !ko.utils.unwrapObservable(options['ifnot']);
6115
6116                            // Don't show anything if an empty name is given (see #2446)
6117                            if (shouldDisplay && !template) {
6118                                shouldDisplay = false;
6119                            }
6120                        }
6121
6122                        if ('foreach' in options) {
6123                            // Render once for each data point (treating data set as empty if shouldDisplay==false)
6124                            var dataArray = (shouldDisplay && options['foreach']) || [];
6125                            templateComputed = ko.renderTemplateForEach(template, dataArray, options, element, bindingContext);
6126                        } else if (!shouldDisplay) {
6127                            ko.virtualElements.emptyNode(element);
6128                        } else {
6129                            // Render once for this single data point (or use the viewModel if no data was provided)
6130                            var innerBindingContext = bindingContext;
6131                            if ('data' in options) {
6132                                innerBindingContext = bindingContext['createChildContext'](options['data'], {
6133                                    'as': options['as'],
6134                                    'noChildContext': options['noChildContext'],
6135                                    'exportDependencies': true
6136                                });
6137                            }
6138                            templateComputed = ko.renderTemplate(template, innerBindingContext, options, element);
6139                        }
6140
6141                        // It only makes sense to have a single template computed per element (otherwise which one should have its output displayed?)
6142                        disposeOldComputedAndStoreNewOne(element, templateComputed);
6143                    }
6144                };
6145
6146                // Anonymous templates can't be rewritten. Give a nice error message if you try to do it.
6147                ko.expressionRewriting.bindingRewriteValidators['template'] = function (bindingValue) {
6148                    var parsedBindingValue = ko.expressionRewriting.parseObjectLiteral(bindingValue);
6149
6150                    if ((parsedBindingValue.length == 1) && parsedBindingValue[0]['unknown'])
6151                        return null; // It looks like a string literal, not an object literal, so treat it as a named template (which is allowed for rewriting)
6152
6153                    if (ko.expressionRewriting.keyValueArrayContainsKey(parsedBindingValue, "name"))
6154                        return null; // Named templates can be rewritten, so return "no error"
6155                    return "This template engine does not support anonymous templates nested within its templates";
6156                };
6157
6158                ko.virtualElements.allowedBindings['template'] = true;
6159            })();
6160
6161            ko.exportSymbol('setTemplateEngine', ko.setTemplateEngine);
6162            ko.exportSymbol('renderTemplate', ko.renderTemplate);
6163            // Go through the items that have been added and deleted and try to find matches between them.
6164            ko.utils.findMovesInArrayComparison = function (left, right, limitFailedCompares) {
6165                if (left.length && right.length) {
6166                    var failedCompares, l, r, leftItem, rightItem;
6167                    for (failedCompares = l = 0; (!limitFailedCompares || failedCompares < limitFailedCompares) && (leftItem = left[l]); ++l) {
6168                        for (r = 0; rightItem = right[r]; ++r) {
6169                            if (leftItem['value'] === rightItem['value']) {
6170                                leftItem['moved'] = rightItem['index'];
6171                                rightItem['moved'] = leftItem['index'];
6172                                right.splice(r, 1);         // This item is marked as moved; so remove it from right list
6173                                failedCompares = r = 0;     // Reset failed compares count because we're checking for consecutive failures
6174                                break;
6175                            }
6176                        }
6177                        failedCompares += r;
6178                    }
6179                }
6180            };
6181
6182            ko.utils.compareArrays = (function () {
6183                var statusNotInOld = 'added', statusNotInNew = 'deleted';
6184
6185                // Simple calculation based on Levenshtein distance.
6186                function compareArrays(oldArray, newArray, options) {
6187                    // For backward compatibility, if the third arg is actually a bool, interpret
6188                    // it as the old parameter 'dontLimitMoves'. Newer code should use { dontLimitMoves: true }.
6189                    options = (typeof options === 'boolean') ? { 'dontLimitMoves': options } : (options || {});
6190                    oldArray = oldArray || [];
6191                    newArray = newArray || [];
6192
6193                    if (oldArray.length < newArray.length)
6194                        return compareSmallArrayToBigArray(oldArray, newArray, statusNotInOld, statusNotInNew, options);
6195                    else
6196                        return compareSmallArrayToBigArray(newArray, oldArray, statusNotInNew, statusNotInOld, options);
6197                }
6198
6199                function compareSmallArrayToBigArray(smlArray, bigArray, statusNotInSml, statusNotInBig, options) {
6200                    var myMin = Math.min,
6201                        myMax = Math.max,
6202                        editDistanceMatrix = [],
6203                        smlIndex, smlIndexMax = smlArray.length,
6204                        bigIndex, bigIndexMax = bigArray.length,
6205                        compareRange = (bigIndexMax - smlIndexMax) || 1,
6206                        maxDistance = smlIndexMax + bigIndexMax + 1,
6207                        thisRow, lastRow,
6208                        bigIndexMaxForRow, bigIndexMinForRow;
6209
6210                    for (smlIndex = 0; smlIndex <= smlIndexMax; smlIndex++) {
6211                        lastRow = thisRow;
6212                        editDistanceMatrix.push(thisRow = []);
6213                        bigIndexMaxForRow = myMin(bigIndexMax, smlIndex + compareRange);
6214                        bigIndexMinForRow = myMax(0, smlIndex - 1);
6215                        for (bigIndex = bigIndexMinForRow; bigIndex <= bigIndexMaxForRow; bigIndex++) {
6216                            if (!bigIndex)
6217                                thisRow[bigIndex] = smlIndex + 1;
6218                            else if (!smlIndex)  // Top row - transform empty array into new array via additions
6219                                thisRow[bigIndex] = bigIndex + 1;
6220                            else if (smlArray[smlIndex - 1] === bigArray[bigIndex - 1])
6221                                thisRow[bigIndex] = lastRow[bigIndex - 1];                  // copy value (no edit)
6222                            else {
6223                                var northDistance = lastRow[bigIndex] || maxDistance;       // not in big (deletion)
6224                                var westDistance = thisRow[bigIndex - 1] || maxDistance;    // not in small (addition)
6225                                thisRow[bigIndex] = myMin(northDistance, westDistance) + 1;
6226                            }
6227                        }
6228                    }
6229
6230                    var editScript = [], meMinusOne, notInSml = [], notInBig = [];
6231                    for (smlIndex = smlIndexMax, bigIndex = bigIndexMax; smlIndex || bigIndex;) {
6232                        meMinusOne = editDistanceMatrix[smlIndex][bigIndex] - 1;
6233                        if (bigIndex && meMinusOne === editDistanceMatrix[smlIndex][bigIndex - 1]) {
6234                            notInSml.push(editScript[editScript.length] = {     // added
6235                                'status': statusNotInSml,
6236                                'value': bigArray[--bigIndex],
6237                                'index': bigIndex
6238                            });
6239                        } else if (smlIndex && meMinusOne === editDistanceMatrix[smlIndex - 1][bigIndex]) {
6240                            notInBig.push(editScript[editScript.length] = {     // deleted
6241                                'status': statusNotInBig,
6242                                'value': smlArray[--smlIndex],
6243                                'index': smlIndex
6244                            });
6245                        } else {
6246                            --bigIndex;
6247                            --smlIndex;
6248                            if (!options['sparse']) {
6249                                editScript.push({
6250                                    'status': "retained",
6251                                    'value': bigArray[bigIndex]
6252                                });
6253                            }
6254                        }
6255                    }
6256
6257                    // Set a limit on the number of consecutive non-matching comparisons; having it a multiple of
6258                    // smlIndexMax keeps the time complexity of this algorithm linear.
6259                    ko.utils.findMovesInArrayComparison(notInBig, notInSml, !options['dontLimitMoves'] && smlIndexMax * 10);
6260
6261                    return editScript.reverse();
6262                }
6263
6264                return compareArrays;
6265            })();
6266
6267            ko.exportSymbol('utils.compareArrays', ko.utils.compareArrays);
6268            (function () {
6269                // Objective:
6270                // * Given an input array, a container DOM node, and a function from array elements to arrays of DOM nodes,
6271                //   map the array elements to arrays of DOM nodes, concatenate together all these arrays, and use them to populate the container DOM node
6272                // * Next time we're given the same combination of things (with the array possibly having mutated), update the container DOM node
6273                //   so that its children is again the concatenation of the mappings of the array elements, but don't re-map any array elements that we
6274                //   previously mapped - retain those nodes, and just insert/delete other ones
6275
6276                // "callbackAfterAddingNodes" will be invoked after any "mapping"-generated nodes are inserted into the container node
6277                // You can use this, for example, to activate bindings on those nodes.
6278
6279                function mapNodeAndRefreshWhenChanged(containerNode, mapping, valueToMap, callbackAfterAddingNodes, index) {
6280                    // Map this array value inside a dependentObservable so we re-map when any dependency changes
6281                    var mappedNodes = [];
6282                    var dependentObservable = ko.dependentObservable(function () {
6283                        var newMappedNodes = mapping(valueToMap, index, ko.utils.fixUpContinuousNodeArray(mappedNodes, containerNode)) || [];
6284
6285                        // On subsequent evaluations, just replace the previously-inserted DOM nodes
6286                        if (mappedNodes.length > 0) {
6287                            ko.utils.replaceDomNodes(mappedNodes, newMappedNodes);
6288                            if (callbackAfterAddingNodes)
6289                                ko.dependencyDetection.ignore(callbackAfterAddingNodes, null, [valueToMap, newMappedNodes, index]);
6290                        }
6291
6292                        // Replace the contents of the mappedNodes array, thereby updating the record
6293                        // of which nodes would be deleted if valueToMap was itself later removed
6294                        mappedNodes.length = 0;
6295                        ko.utils.arrayPushAll(mappedNodes, newMappedNodes);
6296                    }, null, { disposeWhenNodeIsRemoved: containerNode, disposeWhen: function () { return !ko.utils.anyDomNodeIsAttachedToDocument(mappedNodes); } });
6297                    return { mappedNodes: mappedNodes, dependentObservable: (dependentObservable.isActive() ? dependentObservable : undefined) };
6298                }
6299
6300                var lastMappingResultDomDataKey = ko.utils.domData.nextKey(),
6301                    deletedItemDummyValue = ko.utils.domData.nextKey();
6302
6303                ko.utils.setDomNodeChildrenFromArrayMapping = function (domNode, array, mapping, options, callbackAfterAddingNodes, editScript) {
6304                    array = array || [];
6305                    if (typeof array.length == "undefined") // Coerce single value into array
6306                        array = [array];
6307
6308                    options = options || {};
6309                    var lastMappingResult = ko.utils.domData.get(domNode, lastMappingResultDomDataKey);
6310                    var isFirstExecution = !lastMappingResult;
6311
6312                    // Build the new mapping result
6313                    var newMappingResult = [];
6314                    var lastMappingResultIndex = 0;
6315                    var currentArrayIndex = 0;
6316
6317                    var nodesToDelete = [];
6318                    var itemsToMoveFirstIndexes = [];
6319                    var itemsForBeforeRemoveCallbacks = [];
6320                    var itemsForMoveCallbacks = [];
6321                    var itemsForAfterAddCallbacks = [];
6322                    var mapData;
6323                    var countWaitingForRemove = 0;
6324
6325                    function itemAdded(value) {
6326                        mapData = { arrayEntry: value, indexObservable: ko.observable(currentArrayIndex++) };
6327                        newMappingResult.push(mapData);
6328                        if (!isFirstExecution) {
6329                            itemsForAfterAddCallbacks.push(mapData);
6330                        }
6331                    }
6332
6333                    function itemMovedOrRetained(oldPosition) {
6334                        mapData = lastMappingResult[oldPosition];
6335                        if (currentArrayIndex !== mapData.indexObservable.peek())
6336                            itemsForMoveCallbacks.push(mapData);
6337                        // Since updating the index might change the nodes, do so before calling fixUpContinuousNodeArray
6338                        mapData.indexObservable(currentArrayIndex++);
6339                        ko.utils.fixUpContinuousNodeArray(mapData.mappedNodes, domNode);
6340                        newMappingResult.push(mapData);
6341                    }
6342
6343                    function callCallback(callback, items) {
6344                        if (callback) {
6345                            for (var i = 0, n = items.length; i < n; i++) {
6346                                ko.utils.arrayForEach(items[i].mappedNodes, function (node) {
6347                                    callback(node, i, items[i].arrayEntry);
6348                                });
6349                            }
6350                        }
6351                    }
6352
6353                    if (isFirstExecution) {
6354                        ko.utils.arrayForEach(array, itemAdded);
6355                    } else {
6356                        if (!editScript || (lastMappingResult && lastMappingResult['_countWaitingForRemove'])) {
6357                            // Compare the provided array against the previous one
6358                            var lastArray = ko.utils.arrayMap(lastMappingResult, function (x) { return x.arrayEntry; }),
6359                                compareOptions = {
6360                                    'dontLimitMoves': options['dontLimitMoves'],
6361                                    'sparse': true
6362                                };
6363                            editScript = ko.utils.compareArrays(lastArray, array, compareOptions);
6364                        }
6365
6366                        for (var i = 0, editScriptItem, movedIndex, itemIndex; editScriptItem = editScript[i]; i++) {
6367                            movedIndex = editScriptItem['moved'];
6368                            itemIndex = editScriptItem['index'];
6369                            switch (editScriptItem['status']) {
6370                                case "deleted":
6371                                    while (lastMappingResultIndex < itemIndex) {
6372                                        itemMovedOrRetained(lastMappingResultIndex++);
6373                                    }
6374                                    if (movedIndex === undefined) {
6375                                        mapData = lastMappingResult[lastMappingResultIndex];
6376
6377                                        // Stop tracking changes to the mapping for these nodes
6378                                        if (mapData.dependentObservable) {
6379                                            mapData.dependentObservable.dispose();
6380                                            mapData.dependentObservable = undefined;
6381                                        }
6382
6383                                        // Queue these nodes for later removal
6384                                        if (ko.utils.fixUpContinuousNodeArray(mapData.mappedNodes, domNode).length) {
6385                                            if (options['beforeRemove']) {
6386                                                newMappingResult.push(mapData);
6387                                                countWaitingForRemove++;
6388                                                if (mapData.arrayEntry === deletedItemDummyValue) {
6389                                                    mapData = null;
6390                                                } else {
6391                                                    itemsForBeforeRemoveCallbacks.push(mapData);
6392                                                }
6393                                            }
6394                                            if (mapData) {
6395                                                nodesToDelete.push.apply(nodesToDelete, mapData.mappedNodes);
6396                                            }
6397                                        }
6398                                    }
6399                                    lastMappingResultIndex++;
6400                                    break;
6401
6402                                case "added":
6403                                    while (currentArrayIndex < itemIndex) {
6404                                        itemMovedOrRetained(lastMappingResultIndex++);
6405                                    }
6406                                    if (movedIndex !== undefined) {
6407                                        itemsToMoveFirstIndexes.push(newMappingResult.length);
6408                                        itemMovedOrRetained(movedIndex);
6409                                    } else {
6410                                        itemAdded(editScriptItem['value']);
6411                                    }
6412                                    break;
6413                            }
6414                        }
6415
6416                        while (currentArrayIndex < array.length) {
6417                            itemMovedOrRetained(lastMappingResultIndex++);
6418                        }
6419
6420                        // Record that the current view may still contain deleted items
6421                        // because it means we won't be able to use a provided editScript.
6422                        newMappingResult['_countWaitingForRemove'] = countWaitingForRemove;
6423                    }
6424
6425                    // Store a copy of the array items we just considered so we can difference it next time
6426                    ko.utils.domData.set(domNode, lastMappingResultDomDataKey, newMappingResult);
6427
6428                    // Call beforeMove first before any changes have been made to the DOM
6429                    callCallback(options['beforeMove'], itemsForMoveCallbacks);
6430
6431                    // Next remove nodes for deleted items (or just clean if there's a beforeRemove callback)
6432                    ko.utils.arrayForEach(nodesToDelete, options['beforeRemove'] ? ko.cleanNode : ko.removeNode);
6433
6434                    var i, j, lastNode, nodeToInsert, mappedNodes, activeElement;
6435
6436                    // Since most browsers remove the focus from an element when it's moved to another location,
6437                    // save the focused element and try to restore it later.
6438                    try {
6439                        activeElement = domNode.ownerDocument.activeElement;
6440                    } catch (e) {
6441                        // IE9 throws if you access activeElement during page load (see issue #703)
6442                    }
6443
6444                    // Try to reduce overall moved nodes by first moving the ones that were marked as moved by the edit script
6445                    if (itemsToMoveFirstIndexes.length) {
6446                        while ((i = itemsToMoveFirstIndexes.shift()) != undefined) {
6447                            mapData = newMappingResult[i];
6448                            for (lastNode = undefined; i;) {
6449                                if ((mappedNodes = newMappingResult[--i].mappedNodes) && mappedNodes.length) {
6450                                    lastNode = mappedNodes[mappedNodes.length - 1];
6451                                    break;
6452                                }
6453                            }
6454                            for (j = 0; nodeToInsert = mapData.mappedNodes[j]; lastNode = nodeToInsert, j++) {
6455                                ko.virtualElements.insertAfter(domNode, nodeToInsert, lastNode);
6456                            }
6457                        }
6458                    }
6459
6460                    // Next add/reorder the remaining items (will include deleted items if there's a beforeRemove callback)
6461                    for (i = 0; mapData = newMappingResult[i]; i++) {
6462                        // Get nodes for newly added items
6463                        if (!mapData.mappedNodes)
6464                            ko.utils.extend(mapData, mapNodeAndRefreshWhenChanged(domNode, mapping, mapData.arrayEntry, callbackAfterAddingNodes, mapData.indexObservable));
6465
6466                        // Put nodes in the right place if they aren't there already
6467                        for (j = 0; nodeToInsert = mapData.mappedNodes[j]; lastNode = nodeToInsert, j++) {
6468                            ko.virtualElements.insertAfter(domNode, nodeToInsert, lastNode);
6469                        }
6470
6471                        // Run the callbacks for newly added nodes (for example, to apply bindings, etc.)
6472                        if (!mapData.initialized && callbackAfterAddingNodes) {
6473                            callbackAfterAddingNodes(mapData.arrayEntry, mapData.mappedNodes, mapData.indexObservable);
6474                            mapData.initialized = true;
6475                            lastNode = mapData.mappedNodes[mapData.mappedNodes.length - 1];     // get the last node again since it may have been changed by a preprocessor
6476                        }
6477                    }
6478
6479                    // Restore the focused element if it had lost focus
6480                    if (activeElement && domNode.ownerDocument.activeElement != activeElement) {
6481                        activeElement.focus();
6482                    }
6483
6484                    // If there's a beforeRemove callback, call it after reordering.
6485                    // Note that we assume that the beforeRemove callback will usually be used to remove the nodes using
6486                    // some sort of animation, which is why we first reorder the nodes that will be removed. If the
6487                    // callback instead removes the nodes right away, it would be more efficient to skip reordering them.
6488                    // Perhaps we'll make that change in the future if this scenario becomes more common.
6489                    callCallback(options['beforeRemove'], itemsForBeforeRemoveCallbacks);
6490
6491                    // Replace the stored values of deleted items with a dummy value. This provides two benefits: it marks this item
6492                    // as already "removed" so we won't call beforeRemove for it again, and it ensures that the item won't match up
6493                    // with an actual item in the array and appear as "retained" or "moved".
6494                    for (i = 0; i < itemsForBeforeRemoveCallbacks.length; ++i) {
6495                        itemsForBeforeRemoveCallbacks[i].arrayEntry = deletedItemDummyValue;
6496                    }
6497
6498                    // Finally call afterMove and afterAdd callbacks
6499                    callCallback(options['afterMove'], itemsForMoveCallbacks);
6500                    callCallback(options['afterAdd'], itemsForAfterAddCallbacks);
6501                }
6502            })();
6503
6504            ko.exportSymbol('utils.setDomNodeChildrenFromArrayMapping', ko.utils.setDomNodeChildrenFromArrayMapping);
6505            ko.nativeTemplateEngine = function () {
6506                this['allowTemplateRewriting'] = false;
6507            }
6508
6509            ko.nativeTemplateEngine.prototype = new ko.templateEngine();
6510            ko.nativeTemplateEngine.prototype.constructor = ko.nativeTemplateEngine;
6511            ko.nativeTemplateEngine.prototype['renderTemplateSource'] = function (templateSource, bindingContext, options, templateDocument) {
6512                var useNodesIfAvailable = !(ko.utils.ieVersion < 9), // IE<9 cloneNode doesn't work properly
6513                    templateNodesFunc = useNodesIfAvailable ? templateSource['nodes'] : null,
6514                    templateNodes = templateNodesFunc ? templateSource['nodes']() : null;
6515
6516                if (templateNodes) {
6517                    return ko.utils.makeArray(templateNodes.cloneNode(true).childNodes);
6518                } else {
6519                    var templateText = templateSource['text']();
6520                    return ko.utils.parseHtmlFragment(templateText, templateDocument);
6521                }
6522            };
6523
6524            ko.nativeTemplateEngine.instance = new ko.nativeTemplateEngine();
6525            ko.setTemplateEngine(ko.nativeTemplateEngine.instance);
6526
6527            ko.exportSymbol('nativeTemplateEngine', ko.nativeTemplateEngine);
6528            (function () {
6529                ko.jqueryTmplTemplateEngine = function () {
6530                    // Detect which version of jquery-tmpl you're using. Unfortunately jquery-tmpl
6531                    // doesn't expose a version number, so we have to infer it.
6532                    // Note that as of Knockout 1.3, we only support jQuery.tmpl 1.0.0pre and later,
6533                    // which KO internally refers to as version "2", so older versions are no longer detected.
6534                    var jQueryTmplVersion = this.jQueryTmplVersion = (function () {
6535                        if (!jQueryInstance || !(jQueryInstance['tmpl']))
6536                            return 0;
6537                        // Since it exposes no official version number, we use our own numbering system. To be updated as jquery-tmpl evolves.
6538                        try {
6539                            if (jQueryInstance['tmpl']['tag']['tmpl']['open'].toString().indexOf('__') >= 0) {
6540                                // Since 1.0.0pre, custom tags should append markup to an array called "__"
6541                                return 2; // Final version of jquery.tmpl
6542                            }
6543                        } catch (ex) { /* Apparently not the version we were looking for */ }
6544
6545                        return 1; // Any older version that we don't support
6546                    })();
6547
6548                    function ensureHasReferencedJQueryTemplates() {
6549                        if (jQueryTmplVersion < 2)
6550                            throw new Error("Your version of jQuery.tmpl is too old. Please upgrade to jQuery.tmpl 1.0.0pre or later.");
6551                    }
6552
6553                    function executeTemplate(compiledTemplate, data, jQueryTemplateOptions) {
6554                        return jQueryInstance['tmpl'](compiledTemplate, data, jQueryTemplateOptions);
6555                    }
6556
6557                    this['renderTemplateSource'] = function (templateSource, bindingContext, options, templateDocument) {
6558                        templateDocument = templateDocument || document;
6559                        options = options || {};
6560                        ensureHasReferencedJQueryTemplates();
6561
6562                        // Ensure we have stored a precompiled version of this template (don't want to reparse on every render)
6563                        var precompiled = templateSource['data']('precompiled');
6564                        if (!precompiled) {
6565                            var templateText = templateSource['text']() || "";
6566                            // Wrap in "with($whatever.koBindingContext) { ... }"
6567                            templateText = "{{ko_with $item.koBindingContext}}" + templateText + "{{/ko_with}}";
6568
6569                            precompiled = jQueryInstance['template'](null, templateText);
6570                            templateSource['data']('precompiled', precompiled);
6571                        }
6572
6573                        var data = [bindingContext['$data']]; // Prewrap the data in an array to stop jquery.tmpl from trying to unwrap any arrays
6574                        var jQueryTemplateOptions = jQueryInstance['extend']({ 'koBindingContext': bindingContext }, options['templateOptions']);
6575
6576                        var resultNodes = executeTemplate(precompiled, data, jQueryTemplateOptions);
6577                        resultNodes['appendTo'](templateDocument.createElement("div")); // Using "appendTo" forces jQuery/jQuery.tmpl to perform necessary cleanup work
6578
6579                        jQueryInstance['fragments'] = {}; // Clear jQuery's fragment cache to avoid a memory leak after a large number of template renders
6580                        return resultNodes;
6581                    };
6582
6583                    this['createJavaScriptEvaluatorBlock'] = function (script) {
6584                        return "{{ko_code ((function() { return " + script + " })()) }}";
6585                    };
6586
6587                    this['addTemplate'] = function (templateName, templateMarkup) {
6588                        document.write("<script type='text/html' id='" + templateName + "'>" + templateMarkup + "<" + "/script>");
6589                    };
6590
6591                    if (jQueryTmplVersion > 0) {
6592                        jQueryInstance['tmpl']['tag']['ko_code'] = {
6593                            open: "__.push($1 || '');"
6594                        };
6595                        jQueryInstance['tmpl']['tag']['ko_with'] = {
6596                            open: "with($1) {",
6597                            close: "} "
6598                        };
6599                    }
6600                };
6601
6602                ko.jqueryTmplTemplateEngine.prototype = new ko.templateEngine();
6603                ko.jqueryTmplTemplateEngine.prototype.constructor = ko.jqueryTmplTemplateEngine;
6604
6605                // Use this one by default *only if jquery.tmpl is referenced*
6606                var jqueryTmplTemplateEngineInstance = new ko.jqueryTmplTemplateEngine();
6607                if (jqueryTmplTemplateEngineInstance.jQueryTmplVersion > 0)
6608                    ko.setTemplateEngine(jqueryTmplTemplateEngineInstance);
6609
6610                ko.exportSymbol('jqueryTmplTemplateEngine', ko.jqueryTmplTemplateEngine);
6611            })();
6612        }));
6613    }());
6614})();

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