/*

 * Metadata - jQuery plugin for parsing metadata from elements

 *

 * Copyright (c) 2006 John Resig, Yehuda Katz, Jörn Zaefferer

 *

 * 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 $.meta.setType

 *

 * @example <p id="one" class="some_class {item_id: 1, item_label: 'Label'}">This is a p</p>

 * @before $.meta.setType("class")

 * @after $("#one").data().item_id == 1; $("#one")[0].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 $.meta.setType("attr", "data")

 * @after $("#one").data().item_id == 1; $("#one")[0].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 $.meta.setType("elem", "script")

 * @after $("#one").data().item_id == 1; $("#one")[0].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 data()

 */



(function($) {

	// settings

	$.meta = {

	  type: "class",

	  name: "data",

	  setType: function(type,name){

	    this.type = type;

	    this.name = name;

	  },

	  cre: /({.*})/,

	  single: 'data'

	};

	

	// reference to original setArray()

	var setArray = $.fn.setArray;

	

	// define new setArray()

	$.fn.setArray = function(arr){

	    return setArray.apply( this, arguments ).each(function(){

	      if ( this.nodeType == 9 || $.isXMLDoc(this) || this.metaDone ) return;

	      

	      var data = "{}";

	      

	      if ( $.meta.type == "class" ) {

	        var m = $.meta.cre.exec( this.className );

	        if ( m )

	          data = m[1];

	      } else if ( $.meta.type == "elem" ) {

	      	if( !this.getElementsByTagName ) return;

	        var e = this.getElementsByTagName($.meta.name);

	        if ( e.length )

	          data = $.trim(e[0].innerHTML);

	      } else if ( this.getAttribute != undefined ) {

	        var attr = this.getAttribute( $.meta.name );

	        if ( attr )

	          data = attr;

	      }

	      

	      if ( !/^{/.test( data ) )

	        data = "{" + data + "}";

	

	      eval("data = " + data);

	

	      if ( $.meta.single )

	        this[ $.meta.single ] = data;

	      else

	        $.extend( this, data );

	      

	      this.metaDone = true;

	    });

	};

	

	/**

	 * Returns the metadata object for the first member of the jQuery object.

	 *

	 * @name data

	 * @descr Returns element's metadata object

	 * @type jQuery

	 * @cat Plugins/Metadata

	 */

	$.fn.data = function(){

	  return this[0][$.meta.single || "data"];

	};

})(jQuery);