PostMessage with multiple functions or custom callbacks

Question

So far I\'ve only seen tutorials for postmessage where one window sends a single kind of message, and the other window interprets the message in only a single way.

What

Answer 1

One pretty easy way to trigger callbacks without passing any actual code would be:

Target

var callbacks = {
  myCallback: function() { doSomething(); }
};
window.addEventListener('message', function (ev) {
  // origin checking etc
  callbacks[ev.data]();
}, false);

Source

target.postMessage('myCallback', 'http://www.example.com');