How to access parent Iframe from JavaScript

Question

Well, I have an IFrame, which calls a same domain page. My problem is that I want to access some information from this parent Iframe from this called page (from JavaScript).

Answer 1

I would recommend using the postMessage API.

In your iframe, call:

window.parent.postMessage({message: 'Hello world'}, 'http://localhost/');

In the page you're including the iframe you can listen for events like this:

window.addEventListener('message', function(event) {
      if(event.origin === 'http://localhost/')
      {
        alert('Received message: ' + event.data.message);
      }
      else
      {
        alert('Origin not allowed!');
      }

    }, false);

By the way, it is also possible to do calls to other windows, and not only iframes.

Read more about the postMessage API on John Resigs blog here