Send messages between a root HTML window and one level of nested iframes

Messenger.js

// Send messeges between a root window and its iframes.
// This works for only one level of iframes - because that was what I needed

// NOTE: jQuery is required

'use strict';

(function(root){


	function broadcast(message){

		// inform top only. top will broadcast to everyone else
		root.top.postMessage(message, "*");
	}

	function receive(handler){

		$(root).on('message', function(e){

			var message = e.originalEvent.data;
			handler(message);

		});
	}

	// if message received on top, broadcast to all iframes
	if (root.top == root) {
		$(root).on('message', function(e){

			var message = e.originalEvent.data;
			$('iframe').each(function(index, element){
				element.contentWindow.postMessage(message, "*");
			});

		});
	}

	var Messenger = {
		broadcast: broadcast,
		receive: receive
	};

	root.Messenger = Messenger;

})(window);



/* Example usage:
*****************

// Somewhere in an iframe:
Messenger.broadcast({
	key: "navigateTo",
	pageName: "placeOrderPage"
});

// Meanwhile, in another iframe:
Messenger.receive(function(message){

	if (message.key == "navigateTo")
		Navigation.navigateTo(message.pageName);

});

*/