/*
 	 * Metadata - jQuery plugin for parsing metadata from elements
 	 *
 	 * Copyright (c) 2006 John Resig, Yehuda Katz, J�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: jquery.metadata.js 3640 2007-10-11 18:34:38Z pmclanahan $
 	 *
 	 */
 	
 	/**
 	 * 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 <p id="one" class="some_class {item_id: 1, item_label: 'Label'}">This is a p</p>
 	 * @before $.metadata.setType("class")
 	 * @after $("#one").metadata().item_id == 1; $("#one").metadata().item_label == "Label"
 	 * @desc Reads metadata from the class attribute
 	 *
 	 * @example <p id="one" class="some_class" data="{item_id: 1, item_label: 'Label'}">This is a p</p>
 	 * @before $.metadata.setType("attr", "data")
 	 * @after $("#one").metadata().item_id == 1; $("#one").metadata().item_label == "Label"
 	 * @desc Reads metadata from a "data" attribute
 	 *
 	 * @example <p id="one" class="some_class"><script>{item_id: 1, item_label: 'Label'}</script>This is a p</p>
 	 * @before $.metadata.setType("elem", "script")
 	 * @after $("#one").metadata().item_id == 1; $("#one").metadata().item_label == "Label"
 	 *
 	 * @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);