Read parent location from within a frame (different domains)

How could an iframe read its parent location URL, the domains of the parent window and the iframe being different?

I know that the "common" answer to this question is that because of the domains conflict, browsers don't allow cross-domain accesses. So the following won开发者_开发百科't work:

parent.location.href

But maybe someone could think out of the box here and propose something similar to the Cross-document messaging hack?

Perhaps you could check document.referrer? Of course, that will only work if the user has not yet clicked a link inside the iframe.

I got it!!

My solution is the following:

1. Use the onload attribute with the frame

<iframe src="http://website.com/" onload="src+='#'+document.location"></iframe>

2. Monitor hash changes in the frame

var referrer = '?';
window.onhashchange = function() {
  var ref = document.location.hash;
  if(ref && ref.length > 1) {
    var t = ref.split('#');
    ref = t[1];
  }
  referrer = ref;
};

And "voilà" :-)

By the way, you'll find some more details about the onhashchange event.