/*
* 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 four 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.
* html5: Values are stored in data-* attributes.
*
* 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
*
* @example <p id="one" class="some_class" data-item_id="1" data-item_label="Label">This is a p</p>
* @before $.metadata.setType("html5")
* @after $("#one").metadata().item_id == 1; $("#one").metadata().item_label == "Label"
* @desc Reads metadata from a series of data-* attributes
*
* @param String type The encoding type
* @param String name The name of the attribute to be used to get metadata (optional)
* @cat Plugins/Metadata
* @descr Sets the type of encoding to be used when loading metadata for the first time
* @type undefined
* @see metadata()
*/
(function($) {
$.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 = "{}";
var getData = function(data) {
if(typeof data != "string") return data;
if( data.indexOf('{') < 0 ) {
data = eval("(" + data + ")");
}
};
var getObject = function(data) {
if(typeof data != "string") return data;
data = eval("(" + data + ")");
return data;
};
if ( settings.type == "html5" ) {
var object = {};
$( elem.attributes ).each(function() {
var name = this.nodeName;
if(name.match(/^data-/)) name = name.replace(/^data-/, '');
else return true;
object[name] = getObject(this.nodeValue);
});
} else {
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;
}
object = getObject(data.indexOf("{") < 0 ? "{" + data + "}" : data);
}
$.data( elem, settings.single, object );
return object;
}
}
});
/**
* 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);