How do you access Content of an Iframe using GWT?

I have a HiddenIframe that i created in GWT which gets response from a post. OnBrowsewerevent() i try to introspect the contents of Iframe for a error code or success.

When i access the Iframe via GWT, I can access it but innerHTML method always null

I write a JSNI method

private native String getMessage()/*-{
    var e = document.getElementById('my_iframe');
    var html = e.contentWindow.document.body.innerHTML;
    return html 
    }-*/;

I always get e as null as Ge开发者_开发百科telementbyID is returning null, When i introspect HTMLusing firebug i can see the Iframe with the ID. What is the best way to solve the problem?

You need to use the GWT specific $doc variable, instead of document. From the GWT JSNI documentation:

When accessing the browser's window and document objects from JSNI, you must reference them as $wnd and $doc, respectively. Your compiled script runs in a nested frame, and $wnd and $doc are automatically initialized to correctly refer to the host page's window and document.