javascript - link element onload

Question

Is there anyway to listen to the onload event for a <link> element?

F.ex:

var link = document.createElement('link');
link.rel = 'stylesheet';
link.href = 'styles.css';

link.onload = link.onreadystatechange = function(e) {
    console.log(e);
};

This works for <script> elements, but not <link>. Is there another way? I just need to know when the styles in the external stylesheet has applied to the DOM.

Update:

Would it be an idea to inject a hidden <iframe>, add the <link> to the head and listen for the window.onload event in the iframe? It should trigger when the css is loaded, but it might not guarantee that it's loaded in the top window...

Answer 1

Today, all modern browsers support the onload event on link tags. So I would guard hacks, such as creating an img element and setting the onerror:

if !('onload' in document.createElement('link')) {
  imgTag = document.createElement(img);
  imgTag.onerror = function() {};
  imgTag.src = ...;
} 

This should provide a workaround for FF-8 and earlier and old Safari & Chrome versions.

minor update:

As Michael pointed out, there are some browser exceptions for which we always want to apply the hack. In Coffeescript:

isSafari5: ->
  !!navigator.userAgent.match(' Safari/') &&
      !navigator.userAgent.match(' Chrom') &&
      !!navigator.userAgent.match(' Version/5.')

# Webkit: 535.23 and above supports onload on link tags.
isWebkitNoOnloadSupport: ->
  [supportedMajor, supportedMinor] = [535, 23]
  if (match = navigator.userAgent.match(/ AppleWebKit/(d+).(d+)/))
    match.shift()
    [major, minor] = [+match[0], +match[1]]
    major < supportedMajor || major == supportedMajor && minor < supportedMinor