Watching for a message in an iframe

Issue

I'm wondering if there's a way in JavaScript/AngularJS to essentially look out for a message of some sort when it appears in an iframe. So say for example I have a form in an iframe, and I complete the form and it tells me I've completed it, is there a way to detect this via JS?

Any help/suggestions would be greatly appreciated.

Solution

Outside iframe listen event

      window.addEventListener( "message",
          function (e) {
                 alert(e.data);
              },false);

Within iframe trigger event

      window.postMessage('form complete');

Answered By - maddygoround