Show content from other website and track the URL

On my JSF page I am trying to show some other website in an iframe and show its URL. I understand now that for security reasons I can only access the URL of the iframe if it is showing some site of my domain. So, I've found that problem a lot of times in the internet, but I couldn't find any solut开发者_开发百科ion. I don't want to read the content of the iframe, but only the URL.

Is there any solution for this requirement? Using an alternative to iframes? Frameset, browser in browser? Popup?

If you want to stick to the iframe option, I would test to see if the innerhtml of the iframe matches that of the website they are meant to reach. The innerhtml in webkit does seem to change as the user browses. The only alternative I can think of is http proxying the web sites, changing the links to refer to your proxy, then telling them they win when the requested proxy URL matches that of the destination.