Question

This is the iframe I’m trying to access:

 <div class='mceBody' id='additionalTxt_b'>         <iframe frameborder='0' id='additionalTxt_f' src='javascript:''' class='punymce'/>  </div> 

Using this line:

frames['additionalTxt_f'].document.getElementsByTagName('body')[0].innerHTML 

For some reason I’m getting ‘frames.additionalTxt_f is undefined’ from firebug. I have similar iframes (dynamically created by punyMCE plugin) on other pages, and they work perfectly fine. And IE7/8 has no problem accessing this iframe either.

Just at a complete loss here. Any ideas on why Firefox can’t find the iframe?

Answer 1

The window.frames[] array is indexed by the [i]frame’s name attribute (aka frame target). id can’t be relied upon to also work — although it may in IE <8, which often thinks names and ids are the same thing.

If you want to access a frame’s content via ID, use the DOM Level 2 HTML contentDocument property instead of the old-school (“DOM Level 0”) frames array:

document.getElementById('additionalTxt_f').contentDocument.body.innerHTML 

…but then, for compatibility with IE <8, you also have to add some fallback cruft, since it doesn’t support contentDocument:

var f= document.getElementById('additionalTxt_f'); var d= f.contentDocument? f.contentDocument : f.contentWindow.document; d.body.innerHTML 

So it’s up to you which method you think is less ugly: the extra script work, or just using the name attribute.