asp.net - How do I get the current location of an iframe?

Question

I have built a basic data entry application allowing users to browse external content in iframe and enter data quickly from the same page. One of the data variables is the URL. Ideally I would like to be able to load the iframes current url into a textbox with javascript. I realize now that this is not going to happen due to security issues.

Has anyone done anything on the server side? or know of any .Net browser in browser controls. The ultimate goal is to just give the user an easy method of extracting the url of the page they are viewing in the iframe It doesn't necessarily HAVE to be an iframe, a browser in the browser would be ideal.

Thanks, Adam

Answer 1

I did some tests in Firefox 3 comparing the value of .src and .documentWindow.location.href in an iframe. (Note: The documentWindow is called contentDocument in Chrome, so instead of .documentWindow.location.href in Chrome it will be .contentDocument.location.href.)

src is always the last URL that was loaded in the iframe without user interaction. I.e., it contains the first value for the URL, or the last value you set up with Javascript from the containing window doing:

document.getElementById("myiframe").src = 'http://www.google.com/';

If the user navigates inside the iframe, you can't anymore access the value of the URL using src. In the previous example, if the user goes away from www.google.com and you do:

alert(document.getElementById("myiframe").src);

You will still get "http://www.google.com".

documentWindow.location.href is only available if the iframe contains a page in the same domain as the containing window, but if it's available it always contains the right value for the URL, even if the user navigates in the iframe.

If you try to access documentWindow.location.href (or anything under documentWindow) and the iframe is in a page that doesn't belong to the domain of the containing window, it will raise an exception:

document.getElementById("myiframe").src = 'http://www.google.com/';
alert(document.getElementById("myiframe").documentWindow.location.href);
Error: Permission denied to get property Location.href

I have not tested any other browser.

Hope it helps!