javascript - Detect failure to load contents of an iframe

Question

I can detect when the content of an iframe has loaded using the load event. Unfortunately, for my purposes, there are two problems with this:

• If there is an error loading the page (404/500, etc), the load event is never fired.
• If some images or other dependencies failed to load, the load event is fired as usual.

Is there some way I can reliably determine if either of the above errors occurred?

I'm writing a semi-web semi-desktop application based on Mozilla/XULRunner, so solutions that only work in Mozilla are welcome.

Answer 1

If you have control over the iframe page (and the pages are on the same domain name), a strategy could be as follows:

• In the parent document, initialize a variable var iFrameLoaded = false;
• When the iframe document is loaded, set this variable in the parent to true calling from the iframe document a parent's function (setIFrameLoaded(); for example).
• check the iFrameLoaded flag using the timer object (set the timer to your preferred timeout limit) - if the flag is still false you can tell that the iframe was not regularly loaded.

I hope this helps.