Events.js

/**
*   @class Events
*
*   @author Matteo Burgassi
*/
/*
	onGoingNotification {
		'event_name01': [
			0 : {
				callback: function(event) {} 			
				context: object_or_class
			}
			1: ...
		]
		'event_name02': ...
	}
*/
Refuel.define('Events',
	function Events() {
		if(this.notify && this.subscribe) return;
		var onGoingNotification = {};
		this.onGoingNotification = onGoingNotification;
		this.notify = function(name, data, bubble){
			if (!name || typeof(name)!=='string'){
				throw new TypeError('Invalid event name ' + name);
			}
			data = data || {};

			
			if (onGoingNotification[name] instanceof Array) {
				var handlers = [].concat(onGoingNotification[name]);
				for (var i = 0, handler; handler = handlers[i]; i++) {
					handler.callback.call(handler.context, data);
				}
			}
		}

		this.subscribe = function(name, callback, context){
			if (!name || typeof(name)!=='string'){
				throw new TypeError('Invalid event name ' + name);
			}
			if (!callback || typeof(callback)!=='function'){
				throw new TypeError('Invalid event callback ' + callback);
			}
			if (!context) context = this;

			if (typeof onGoingNotification[name] === 'undefined') {
				onGoingNotification[name] = [];
			}
			else {
				//if the same callback is subscribed to the same event, remove it
				this.unsubscribe(name, callback);
			}

			var handler = {
				'callback': callback,
				'context': context
			}
			onGoingNotification[name].push(handler);
		}

		this.isSubscribed = function(name) {
			return !(Refuel.isUndefined(onGoingNotification[name]) || onGoingNotification[name].length===0);
		}

		this.unsubscribe = function(name, callback) {
			if(!name || typeof name !== "string" || (callback && typeof callback !== "function")){
				throw new TypeError("name is not defined or wrong callback");
			}
			if (callback) {
				for (var i=0, l=onGoingNotification[name].length;  i<l; i++) {
					if(onGoingNotification[name][i].callback.toString() === callback.toString()){
						onGoingNotification[name].splice(i, 1);
						return;
					}
				}
			}
			else{
				delete onGoingNotification[name];
			}
		}

});