Source: modules/event.js

/**
 * Event
 *
 * Event api wrapper
 * @todo Add method for triggering events
 */
(function (undefined){

	"use strict";

	var _add_remove, e, _attach_delegate;

	_add_remove = function (sel, event, callback, add)
	{
		var i, len;

		// Multiple events? Run recursively!
		if ( ! event.match(/^([\w\-]+)$/))
		{
			event = event.split(" ");

			len = event.length;

			for (i = 0; i < len; i++)
			{
				_add_remove(sel, event[i], callback, add);
			}

			return;
		}

		// Bind the event
		(add === true)
			? sel.addEventListener(event, callback, false)
			: sel.removeEventListener(event, callback, false);
	};

	_attach_delegate = function(sel, target, event, callback)
	{
		// attach the listener to the parent object
		_add_remove(sel, event, function(e){

			var elem, t;

			// Get the live version of the target selector
			t = $_.$(target, sel);

			// Check each element to see if it matches the target
			for(elem in t)
			{
				// Fire target callback when event bubbles from target
				if(e.target == t[elem])
				{
					// Trigger the event callback
					callback.call(t[elem], e);

					// Stop event propegation
					e.stopPropagation();
				}
			}

		}, true);
	};

	// --------------------------------------------------------------------------

	/**
	 * Event Listener module
	 *
	 * @namespace
	 * @name event
	 * @memberOf $_
	 */
	e = {
		/**
		 * Create a custom event
		 *
		 * @memberOf $_.event
		 * @name create
		 * @function
		 * @example Eg. var event = $_("#selector").event.create('foo', {});
		 * @param {string} name
		 * @param {object} [data]
		 * @return {Object}
		 */
		create: function(name, data)
		{
			data = data || {};
			
				// Okay, I guess we have to do this the hard way... :(
				var e = document.createEvent('CustomEvent');
				e.initCustomEvent(name, true, true, data);

				return e;
		},
		/**
		 * Adds an event that returns a callback when triggered on the selected
		 * event and selector
		 *
		 * @memberOf $_.event
		 * @name add
		 * @function
		 * @example Eg. $_("#selector").event.add("click", do_something());
		 * @param {string} event
		 * @param {function} callback
		 */
		add: function (event, callback)
		{
			$_.each(function(e){
				_add_remove(e, event, callback, true);
			});
		},
		/**
		 * Removes an event bound the the specified selector, event type, and callback
		 *
		 * @memberOf $_.event
		 * @name remove
		 * @function
		 * @example Eg. $_("#selector").event.remove("click", do_something());
		 * @param {string} event
		 * @param {string} callback
		 */
		remove: function (event, callback)
		{
			$_.each(function(e){
				_add_remove(e, event, callback, false);
			});
		},
		/**
		 * Binds a persistent event to the document
		 *
		 * @memberOf $_.event
		 * @name live
		 * @function
		 * @example Eg. $_.event.live(".button", "click", do_something());
		 * @param {string} target
		 * @param {string} event
		 * @param {function} callback
		 */
		live: function (target, event, callback)
		{
			_attach_delegate(document.documentElement, target, event, callback);
		},
		/**
		 * Binds an event to a parent object
		 *
		 * @memberOf $_.event
		 * @name delegate
		 * @function
		 * @example Eg. $_("#parent").delegate(".button", "click", do_something());
		 * @param {string} target
		 * @param {string} event
		 * @param {function} callback
		 */
		delegate: function (target, event, callback)
		{
			$_.each(function(e){
				_attach_delegate(e, target, event, callback);
			});
		},
		/**
		 * Trigger an event to fire
		 *
		 * @memberOf $_.event
		 * @name trigger
		 * @function
		 * @example Eg. $_("#my_id").trigger('click');
		 * @param {object} event
		 * @return {boolean}
		 */
		trigger: function(event)
		{
			var target = this.el;
			return target.dispatchEvent(event);
		}
	};

	$_.ext('event', e);

}());