GlobalEvents.js

(function(window){

	var EVENT_EXISTS = 'GlobalEvents: Event already exists.';

	var eventIsRunning, 
		_eventStack,
		_findByName,
		stackEvent,
		removeEvent,
		eventListener,
		listen, unlisten,
		_set, _rem, _parse,
		_storage;

	_storage = window.localStorage;
	eventIsRunning = false;
	_eventStack = [];
	_findByName = function (eventName) {
		var evArray = _eventStack.filter(function(ev) {
			return ev.name === eventName;
		});

		return evArray.length ? evArray[0] : null;
	};
	stackEvent = function (eventName, callback, args) {
		if (_findByName(eventName)) {
			throw EVENT_EXISTS;
		} else {
			var ev = {
				name: eventName,
				callback: callback
			};
			if (args) {
				ev.args = args;
			}
			_eventStack.push(ev);
	    }
	};
	removeEvent = function (eventName) {
		var ev = _findByName(eventName);
		var idx = _eventStack.indexOf(ev);
		_eventStack.splice(idx, 1);
	};
	eventListener = function (e) {
		var ev = _findByName(e.key),
			val = e.newValue,
			params = [];
		if (ev && !eventIsRunning) {
			eventIsRunning = true;
			ev.args && params.push(ev.args);
			val && val !== '_evt' && params.push(_parse(val));
			ev.callback.apply(this, params);
			setTimeout(function() {
				eventIsRunning = false;
			}, 10);
		}
	};
	listen = function () {
		window.addEventListener('storage', eventListener);
	};
	unlisten = function () {
		window.removeEventListener('storage', eventListener);
	};

	_set = function (key, value) {
		return _storage.setItem(key, value || '_evt');
	};
	_rem = function (key) {
		return _storage.removeItem(key);
	};
	_parse = function (val) {
		try {
			return JSON.parse(val);
		} catch (e) {}

		return val;
	};

	function GlobalEvents() {
		//begin listening for events
		unlisten();
		listen();
	};

	GlobalEvents.prototype = {
		on: stackEvent,
		off: removeEvent,
		trigger: function (eventName, transportObject) {
			_set(eventName, transportObject);
			unlisten();
			setTimeout(function() {
				_rem(eventName);
				listen();				
			});				
		}
	};

	window.GlobalEvents = new GlobalEvents();

})(window);


//usage #1 - trigger the event
//listen to the event in one window
GlobalEvents.on('test', function() {
  //do something when the event fires
});

//fire the event from another window
GlobalEvents.trigger('test');

//usage #2 - trigger the event an transport an object between windows
//listen to the event in one window
GlobalEvents.on('test', function(transportObj) {
  //do something with transportObj when the event fires
});

//fire the event from another window and send an object
GlobalEvents.trigger('test', {foo:bar,baz:bar});