[569] | 1 | /* |
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| 2 | * Metadata - jQuery plugin for parsing metadata from elements |
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| 3 | * |
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| 4 | * Copyright (c) 2006 John Resig, Yehuda Katz, Jéörn Zaefferer, Paul McLanahan |
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| 5 | * |
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| 6 | * Dual licensed under the MIT and GPL licenses: |
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| 7 | * http://www.opensource.org/licenses/mit-license.php |
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| 8 | * http://www.gnu.org/licenses/gpl.html |
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| 9 | * |
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| 10 | * Revision: $Id: jquery.metadata.js 4187 2007-12-16 17:15:27Z joern.zaefferer $ |
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| 11 | * |
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| 12 | */ |
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| 13 | |
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| 14 | /** |
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| 15 | * Sets the type of metadata to use. Metadata is encoded in JSON, and each property |
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| 16 | * in the JSON will become a property of the element itself. |
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| 17 | * |
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| 18 | * There are three supported types of metadata storage: |
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| 19 | * |
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| 20 | * attr: Inside an attribute. The name parameter indicates *which* attribute. |
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| 21 | * |
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| 22 | * class: Inside the class attribute, wrapped in curly braces: { } |
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| 23 | * |
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| 24 | * elem: Inside a child element (e.g. a script tag). The |
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| 25 | * name parameter indicates *which* element. |
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| 26 | * |
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| 27 | * The metadata for an element is loaded the first time the element is accessed via jQuery. |
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| 28 | * |
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| 29 | * As a result, you can define the metadata type, use $(expr) to load the metadata into the elements |
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| 30 | * matched by expr, then redefine the metadata type and run another $(expr) for other elements. |
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| 31 | * |
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| 32 | * @name $.metadata.setType |
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| 33 | * |
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| 34 | * @example <p id="one" class="some_class {item_id: 1, item_label: 'Label'}">This is a p</p> |
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| 35 | * @before $.metadata.setType("class") |
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| 36 | * @after $("#one").metadata().item_id == 1; $("#one").metadata().item_label == "Label" |
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| 37 | * @desc Reads metadata from the class attribute |
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| 38 | * |
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| 39 | * @example <p id="one" class="some_class" data="{item_id: 1, item_label: 'Label'}">This is a p</p> |
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| 40 | * @before $.metadata.setType("attr", "data") |
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| 41 | * @after $("#one").metadata().item_id == 1; $("#one").metadata().item_label == "Label" |
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| 42 | * @desc Reads metadata from a "data" attribute |
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| 43 | * |
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| 44 | * @example <p id="one" class="some_class"><script>{item_id: 1, item_label: 'Label'}</script>This is a p</p> |
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| 45 | * @before $.metadata.setType("elem", "script") |
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| 46 | * @after $("#one").metadata().item_id == 1; $("#one").metadata().item_label == "Label" |
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| 47 | * @desc Reads metadata from a nested script element |
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| 48 | * |
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| 49 | * @param String type The encoding type |
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| 50 | * @param String name The name of the attribute to be used to get metadata (optional) |
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| 51 | * @cat Plugins/Metadata |
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| 52 | * @descr Sets the type of encoding to be used when loading metadata for the first time |
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| 53 | * @type undefined |
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| 54 | * @see metadata() |
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| 55 | */ |
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| 56 | |
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| 57 | (function($) { |
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| 58 | |
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| 59 | $.extend({ |
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| 60 | metadata : { |
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| 61 | defaults : { |
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| 62 | type: 'class', |
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| 63 | name: 'metadata', |
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| 64 | cre: /({.*})/, |
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| 65 | single: 'metadata' |
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| 66 | }, |
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| 67 | setType: function( type, name ){ |
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| 68 | this.defaults.type = type; |
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| 69 | this.defaults.name = name; |
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| 70 | }, |
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| 71 | get: function( elem, opts ){ |
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| 72 | var settings = $.extend({},this.defaults,opts); |
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| 73 | // check for empty string in single property |
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| 74 | if ( !settings.single.length ) settings.single = 'metadata'; |
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| 75 | |
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| 76 | var data = $.data(elem, settings.single); |
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| 77 | // returned cached data if it already exists |
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| 78 | if ( data ) return data; |
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| 79 | |
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| 80 | data = "{}"; |
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| 81 | |
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| 82 | if ( settings.type == "class" ) { |
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| 83 | var m = settings.cre.exec( elem.className ); |
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| 84 | if ( m ) |
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| 85 | data = m[1]; |
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| 86 | } else if ( settings.type == "elem" ) { |
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| 87 | if( !elem.getElementsByTagName ) |
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| 88 | return undefined; |
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| 89 | var e = elem.getElementsByTagName(settings.name); |
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| 90 | if ( e.length ) |
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| 91 | data = $.trim(e[0].innerHTML); |
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| 92 | } else if ( elem.getAttribute != undefined ) { |
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| 93 | var attr = elem.getAttribute( settings.name ); |
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| 94 | if ( attr ) |
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| 95 | data = attr; |
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| 96 | } |
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| 97 | |
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| 98 | if ( data.indexOf( '{' ) <0 ) |
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| 99 | data = "{" + data + "}"; |
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| 100 | |
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| 101 | data = eval("(" + data + ")"); |
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| 102 | |
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| 103 | $.data( elem, settings.single, data ); |
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| 104 | return data; |
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| 105 | } |
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| 106 | } |
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| 107 | }); |
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| 108 | |
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| 109 | /** |
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| 110 | * Returns the metadata object for the first member of the jQuery object. |
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| 111 | * |
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| 112 | * @name metadata |
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| 113 | * @descr Returns element's metadata object |
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| 114 | * @param Object opts An object contianing settings to override the defaults |
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| 115 | * @type jQuery |
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| 116 | * @cat Plugins/Metadata |
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| 117 | */ |
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| 118 | $.fn.metadata = function( opts ){ |
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| 119 | return $.metadata.get( this[0], opts ); |
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| 120 | }; |
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| 121 | |
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| 122 | })(jQuery); |
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