https://vinayakumarr.github.io/vendor/js/jquery.toc.js

1/*
2 * Table of Contents jQuery Plugin - jquery.toc
3 *
4 * Copyright 2013 Nikhil Dabas
5 * 
6 * Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except
7 * in compliance with the License.  You may obtain a copy of the License at
8 *
9 *     http://www.apache.org/licenses/LICENSE-2.0
10 *
11 * Unless required by applicable law or agreed to in writing, software distributed under the License
12 * is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express
13 * or implied.  See the License for the specific language governing permissions and limitations
14 * under the License.
15 */
16
17(function ($) {
18    "use strict";
19
20    // Builds a list with the table of contents in the current selector.
21    // options:
22    //   content: where to look for headings
23    //   headings: string with a comma-separated list of selectors to be used as headings, ordered
24    //   by their relative hierarchy level
25    var toc = function (options) {
26        return this.each(function () {
27            var root = $(this),
28                data = root.data(),
29                thisOptions,
30                stack = [root], // The upside-down stack keeps track of list elements
31                listTag = this.tagName,
32                currentLevel = 0,
33                headingSelectors;
34
35            // Defaults: plugin parameters override data attributes, which override our defaults
36            thisOptions = $.extend(
37                {content: "body", headings: "h1,h2,h3"},
38                {content: data.toc || undefined, headings: data.tocHeadings || undefined},
39                options
40            );
41            headingSelectors = thisOptions.headings.split(",");
42
43            // Set up some automatic IDs if we do not already have them
44            $(thisOptions.content).find(thisOptions.headings).attr("id", function (index, attr) {
45                // Generate a valid ID: must start with a letter, and contain only letters and
46                // numbers. All other characters are replaced with underscores.
47                return attr ||
48                    $(this).text().replace(/^[^A-Za-z]*/, "").replace(/[^A-Za-z0-9]+/g, "_");
49            }).each(function () {
50                // What level is the current heading?
51                var elem = $(this), level = $.map(headingSelectors, function (selector, index) {
52                    return elem.is(selector) ? index : undefined;
53                })[0];
54
55                if (level > currentLevel) {
56                    // If the heading is at a deeper level than where we are, start a new nested
57                    // list, but only if we already have some list items in the parent. If we do
58                    // not, that means that we're skipping levels, so we can just add new list items
59                    // at the current level.
60                    // In the upside-down stack, unshift = push, and stack[0] = the top.
61                    var parentItem = stack[0].children("li:last")[0];
62                    if (parentItem) {
63                        stack.unshift($("<" + listTag + "/>").appendTo(parentItem));
64                    }
65                } else {
66                    // Truncate the stack to the current level by chopping off the 'top' of the
67                    // stack. We also need to preserve at least one element in the stack - that is
68                    // the containing element.
69                    stack.splice(0, Math.min(currentLevel - level, Math.max(stack.length - 1, 0)));
70                }
71
72                // Add the list item
73                $("<li/>").appendTo(stack[0]).append(
74                    $("<a/>").text(elem.text()).attr("href", "#" + elem.attr("id"))
75                );
76
77                currentLevel = level;
78            });
79        });
80    }, old = $.fn.toc;
81
82    $.fn.toc = toc;
83
84    $.fn.toc.noConflict = function () {
85        $.fn.toc = old;
86        return this;
87    };
88
89    // Data API
90    $(function () {
91        toc.call($("[data-toc]"));
92    });
93}(window.jQuery));