https://obzorzarplat.ru/_js/jquery.example.js

1/*
2 * jQuery Form Example Plugin 1.4.2
3 * Populate form inputs with example text that disappears on focus.
4 *
5 * e.g.
6 *  $('input#name').example('Bob Smith');
7 *  $('input[@title]').example(function() {
8 *    return $(this).attr('title');
9 *  });
10 *  $('textarea#message').example('Type your message here', {
11 *    className: 'example_text'
12 *  });
13 *
14 * Copyright (c) Paul Mucur (http://mucur.name), 2007-2008.
15 * Dual-licensed under the BSD (BSD-LICENSE.txt) and GPL (GPL-LICENSE.txt)
16 * licenses.
17 *
18 * This program is free software; you can redistribute it and/or modify
19 * it under the terms of the GNU General Public License as published by
20 * the Free Software Foundation; either version 2 of the License, or
21 * (at your option) any later version.
22 *
23 * This program is distributed in the hope that it will be useful,
24 * but WITHOUT ANY WARRANTY; without even the implied warranty of
25 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
26 * GNU General Public License for more details.
27 */
28(function($) {
29
30  $.fn.example = function(text, args) {
31
32    /* Only calculate once whether a callback has been used. */
33    var isCallback = $.isFunction(text);
34
35    /* Merge the arguments and given example text into one options object. */
36    var options = $.extend({}, args, {example: text});
37
38    return this.each(function() {
39
40      /* Reduce method calls by saving the current jQuery object. */
41      var $this = $(this);
42
43      /* Merge the plugin defaults with the given options and, if present,
44       * any metadata.
45       */
46      if ($.metadata) {
47        var o = $.extend({}, $.fn.example.defaults, $this.metadata(), options);
48      } else {
49        var o = $.extend({}, $.fn.example.defaults, options);
50      }
51
52      /* The following event handlers only need to be bound once
53       * per class name. In order to do this, an array of used
54       * class names is stored and checked on each use of the plugin.
55       * If the class name is in the array then this whole section
56       * is skipped. If not, the events are bound and the class name
57       * added to the array.
58       *
59       * As of 1.3.2, the class names are stored as keys in the
60       * array, rather than as elements. This removes the need for
61       * $.inArray().
62       */
63      if (!$.fn.example.boundClassNames[o.className]) {
64
65        /* Because Gecko-based browsers cache form values
66         * but ignore all other attributes such as class, all example
67         * values must be cleared on page unload to prevent them from
68         * being saved.
69         */
70        $(window).unload(function() {
71          $('.' + o.className).val('');
72        });
73
74        /* Clear fields that are still examples before any form is submitted
75         * otherwise those examples will be sent along as well.
76         *
77         * Prior to 1.3, this would only be bound to forms that were
78         * parents of example fields but this meant that a page with
79         * multiple forms would not work correctly.
80         */
81        $('form').submit(function() {
82
83          /* Clear only the fields inside this particular form. */
84          $(this).find('.' + o.className).val('');
85        });
86
87        /* Add the class name to the array. */
88        $.fn.example.boundClassNames[o.className] = true;
89      }
90
91      /* Internet Explorer will cache form values even if they are cleared
92       * on unload, so this will clear any value that matches the example
93       * text and hasn't been specified in the value attribute.
94       *
95       * If a callback is used, it is not possible or safe to predict
96       * what the example text is going to be so all non-default values
97       * are cleared. This means that caching is effectively disabled for
98       * that field.
99       *
100       * Many thanks to Klaus Hartl for helping resolve this issue.
101       */
102      if ($.browser.msie && !$this.attr('defaultValue') && (isCallback || $this.val() == o.example))
103        $this.val('');
104
105      /* Initially place the example text in the field if it is empty
106       * and doesn't have focus yet.
107       */
108      if ($this.val() == '' && this != document.activeElement) {
109        $this.addClass(o.className);
110
111        /* The text argument can now be a function; if this is the case,
112         * call it, passing the current element as `this`.
113         */
114        $this.val(isCallback ? o.example.call(this) : o.example);
115      }
116
117      /* Make the example text disappear when someone focuses.
118       *
119       * To determine whether the value of the field is an example or not,
120       * check for the example class name only; comparing the actual value
121       * seems wasteful and can stop people from using example values as real
122       * input.
123       */
124      $this.focus(function() {
125
126        /* jQuery 1.1 has no hasClass(), so is() must be used instead. */
127        if ($(this).is('.' + o.className)) {
128          $(this).val('');
129          $(this).removeClass(o.className);
130        }
131      });
132
133      /* Detect a change event to the field and remove the example class. */
134      $this.change(function() {
135        if ($(this).is('.' + o.className)) {
136          $(this).removeClass(o.className);
137        }
138      });
139
140      /* Make the example text reappear if the input is blank on blurring. */
141      $this.blur(function() {
142        if ($(this).val() == '') {
143          $(this).addClass(o.className);
144
145          /* Re-evaluate the callback function every time the user
146           * blurs the field without entering anything. While this

147           * is not as efficient as caching the value, it allows for
148           * more dynamic applications of the plugin.
149           */
150          $(this).val(isCallback ? o.example.call(this) : o.example);
151        }
152      });
153    });
154  };
155
156  /* Users can override the defaults for the plugin like so:
157   *
158   *   $.fn.example.defaults.className = 'not_example';
159   */
160  $.fn.example.defaults = {
161    className: 'example'
162  };
163
164  /* All the class names used are stored as keys in the following array. */
165  $.fn.example.boundClassNames = [];
166
167})(jQuery);