2 * Metadata - jQuery plugin for parsing metadata from elements
4 * Copyright (c) 2006 John Resig, Yehuda Katz, J�örn Zaefferer, Paul McLanahan
6 * Dual licensed under the MIT and GPL licenses:
7 * http://www.opensource.org/licenses/mit-license.php
8 * http://www.gnu.org/licenses/gpl.html
15 * Sets the type of metadata to use. Metadata is encoded in JSON, and each property
16 * in the JSON will become a property of the element itself.
18 * There are three supported types of metadata storage:
20 * attr: Inside an attribute. The name parameter indicates *which* attribute.
22 * class: Inside the class attribute, wrapped in curly braces: { }
24 * elem: Inside a child element (e.g. a script tag). The
25 * name parameter indicates *which* element.
27 * The metadata for an element is loaded the first time the element is accessed via jQuery.
29 * As a result, you can define the metadata type, use $(expr) to load the metadata into the elements
30 * matched by expr, then redefine the metadata type and run another $(expr) for other elements.
32 * @name $.metadata.setType
34 * @example <p id="one" class="some_class {item_id: 1, item_label: 'Label'}">This is a p</p>
35 * @before $.metadata.setType("class")
36 * @after $("#one").metadata().item_id == 1; $("#one").metadata().item_label == "Label"
37 * @desc Reads metadata from the class attribute
39 * @example <p id="one" class="some_class" data="{item_id: 1, item_label: 'Label'}">This is a p</p>
40 * @before $.metadata.setType("attr", "data")
41 * @after $("#one").metadata().item_id == 1; $("#one").metadata().item_label == "Label"
42 * @desc Reads metadata from a "data" attribute
44 * @example <p id="one" class="some_class"><script>{item_id: 1, item_label: 'Label'}</script>This is a p</p>
45 * @before $.metadata.setType("elem", "script")
46 * @after $("#one").metadata().item_id == 1; $("#one").metadata().item_label == "Label"
47 * @desc Reads metadata from a nested script element
49 * @param String type The encoding type
50 * @param String name The name of the attribute to be used to get metadata (optional)
51 * @cat Plugins/Metadata
52 * @descr Sets the type of encoding to be used when loading metadata for the first time
67 setType: function( type, name ){
68 this.defaults.type = type;
69 this.defaults.name = name;
71 get: function( elem, opts ){
72 var settings = $.extend({},this.defaults,opts);
73 // check for empty string in single property
74 if ( !settings.single.length ) settings.single = 'metadata';
76 var data = $.data(elem, settings.single);
77 // returned cached data if it already exists
78 if ( data ) return data;
82 if ( settings.type == "class" ) {
83 var m = settings.cre.exec( elem.className );
86 } else if ( settings.type == "elem" ) {
87 if( !elem.getElementsByTagName )
89 var e = elem.getElementsByTagName(settings.name);
91 data = $.trim(e[0].innerHTML);
92 } else if ( elem.getAttribute != undefined ) {
93 var attr = elem.getAttribute( settings.name );
98 if ( data.indexOf( '{' ) <0 )
99 data = "{" + data + "}";
101 data = eval("(" + data + ")");
103 $.data( elem, settings.single, data );
110 * Returns the metadata object for the first member of the jQuery object.
113 * @descr Returns element's metadata object
114 * @param Object opts An object contianing settings to override the defaults
116 * @cat Plugins/Metadata
118 $.fn.metadata = function( opts ){
119 return $.metadata.get( this[0], opts );