/*
 * 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: $Id$
 *
 */

/**
 * 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(d) {
  d.extend({metadata:{defaults:{type:"class", name:"metadata", cre:/({.*})/, single:"metadata"}, setType:function(b, f) {
    this.defaults.type = b;
    this.defaults.name = f
  }, get:function(b, f) {
    var c = d.extend({}, this.defaults, f);
    if(!c.single.length) {
      c.single = "metadata"
    }
    var a = d.data(b, c.single);
    if(a) {
      return a
    }
    a = "{}";
    if(c.type == "class") {
      var e = c.cre.exec(b.className);
      if(e) {
        a = e[1]
      }
    }else {
      if(c.type == "elem") {
        if(!b.getElementsByTagName) {
          return
        }
        e = b.getElementsByTagName(c.name);
        if(e.length) {
          a = d.trim(e[0].innerHTML)
        }
      }else {
        if(b.getAttribute != undefined) {
          if(e = b.getAttribute(c.name)) {
            a = e
          }
        }
      }
    }
    if(a.indexOf("{") < 0) {
      a = "{" + a + "}"
    }
    a = eval("(" + a + ")");
    d.data(b, c.single, a);
    return a
  }}});
  d.fn.metadata = function(b) {
    return d.metadata.get(this[0], b)
  }
})(jQuery);