iframe behaviour of onload vs addEventListener('load')

Question

I\'ve been playing around with adding hidden iframe elements to a page, and I want to manipulate the DOM of the these once loaded. I\'ve noticed that I can\'t start manipulating

Answer 1

addEventListener() function needs 3 arguments! Take a look at https://developer.mozilla.org/en/DOM/element.addEventListener

The 3rd argument is marked as optional, but then they write:

Note that this parameter is not optional in all browser versions.

I'm not sure when and where it is required, but my tests on FF4 threw an exception when calling the addEventListener with 2 arguments:

uncaught exception: [Exception... "Not enough arguments" nsresult: "0x80570001 (NS_ERROR_XPC_NOT_ENOUGH_ARGS)" location: "JS frame :: http://localhost/index.php :: :: line 10" data: no]

By the way, your code works well in Chrome [the string loaded! is logged in console].

Like FF, IE9 needs the 3rd argument in the standards mode (with ). IE9 is the first IE that supports W3C's event model. So in the earlier versions we need to try attachEvent. I don't have earlier IEs, but it worked in IE7/8 Standards Mode and even in Quirks Mode in IE9. Here is the code I used: