Question

I am trying to build a browser extension using KangoExtensions.

I’m appending the following iframe to the body:

<iframe id="iframe" name="iframe" allowtransparency="yes"
    style="position: absolute; top: -41px; left: 0px; right: 0px; width: 100%; height: 41px; z-index: 10000; border: 0px none;">
</iframe>

After I append the iframe I try to write the content:

window.onload= function(){
   $(iframe).ready(function(){
                var iframeDocument = false;
                if(iframe.contentDocument) {
                    iframeDocument = iframe.contentDocument;
                } else if(iframe.contentWindow) {
                    iframeDocument = iframe.contentWindow.document;
                } else if(window.frames['iframe'].document) {
                    iframeDocument = window.frames['iframe'].document;
                }
                if(iframeDocument) {
                    iframeDocument.open();
                    iframeDocument.write(content);
                }
            });
 };

The extension works in all browsers (Chrome, Opera, IE) but in Firefox it does not write anything to the iframe. If I use iframeDocument.body.innerHTML = content; the content is visible for a few milliseconds and then disappears. I only see a gray(ish) rectangle.

Are there some limitations to what one can do with iframes in a Firefox extension?

Answer 1

Seems iframe not compeltly loaded when you trying to modify it.

Change $(iframe).ready(function(){...}) to iframe.addEventListener('load', function(){...}).