/* * Metadata - jQuery plugin for parsing metadata from elements * * Copyright (c) 2006 John Resig, Yehuda Katz, J�rn Zaefferer, Paul McLanahan * * Dual licensed under the MIT and GPL licenses: * http://www.opensource.org/licenses/mit-license.php * http://www.gnu.org/licenses/gpl.html * * Revision: $Id$ * */ /** * Sets the type of metadata to use. Metadata is encoded in JSON, and each property * in the JSON will become a property of the element itself. * * There are three supported types of metadata storage: * * attr: Inside an attribute. The name parameter indicates *which* attribute. * * class: Inside the class attribute, wrapped in curly braces: { } * * elem: Inside a child element (e.g. a script tag). The * name parameter indicates *which* element. * * The metadata for an element is loaded the first time the element is accessed via jQuery. * * As a result, you can define the metadata type, use $(expr) to load the metadata into the elements * matched by expr, then redefine the metadata type and run another $(expr) for other elements. * * @name $.metadata.setType * * @example

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* @before $.metadata.setType("class") * @after $("#one").metadata().item_id == 1; $("#one").metadata().item_label == "Label" * @desc Reads metadata from the class attribute * * @example

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* @before $.metadata.setType("attr", "data") * @after $("#one").metadata().item_id == 1; $("#one").metadata().item_label == "Label" * @desc Reads metadata from a "data" attribute * * @example

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* @before $.metadata.setType("elem", "script") * @after $("#one").metadata().item_id == 1; $("#one").metadata().item_label == "Label" * @desc Reads metadata from a nested script element * * @param String type The encoding type * @param String name The name of the attribute to be used to get metadata (optional) * @cat Plugins/Metadata * @descr Sets the type of encoding to be used when loading metadata for the first time * @type undefined * @see metadata() */ (function($) { $.extend({ metadata : { defaults : { type: 'class', name: 'metadata', cre: /({.*})/, single: 'metadata' }, setType: function( type, name ){ this.defaults.type = type; this.defaults.name = name; }, get: function( elem, opts ){ var settings = $.extend({},this.defaults,opts); // check for empty string in single property if ( !settings.single.length ) settings.single = 'metadata'; var data = $.data(elem, settings.single); // returned cached data if it already exists if ( data ) return data; data = "{}"; if ( settings.type == "class" ) { var m = settings.cre.exec( elem.className ); if ( m ) data = m[1]; } else if ( settings.type == "elem" ) { if( !elem.getElementsByTagName ) return; var e = elem.getElementsByTagName(settings.name); if ( e.length ) data = $.trim(e[0].innerHTML); } else if ( elem.getAttribute != undefined ) { var attr = elem.getAttribute( settings.name ); if ( attr ) data = attr; } if ( data.indexOf( '{' ) <0 ) data = "{" + data + "}"; data = eval("(" + data + ")"); $.data( elem, settings.single, data ); return data; } } }); /** * Returns the metadata object for the first member of the jQuery object. * * @name metadata * @descr Returns element's metadata object * @param Object opts An object contianing settings to override the defaults * @type jQuery * @cat Plugins/Metadata */ $.fn.metadata = function( opts ){ return $.metadata.get( this[0], opts ); }; })(jQuery);