/*
  * Metadata - jQuery plugin for parsing metadata from elements
  *
  * Copyright (c) 2006 John Resig, Yehuda Katz, J�örn 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"
  * @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);