How to determine if content in popup window is loaded
<p>I need to set some contextData for a popup window from its parent.  I try this:</p>

<pre><code>var some contextData = {};
$(function() {
    $('#clickme').click(function() {
        var w = window.open('http://jsfiddle.net');

        w.contextData = contextData            
        //w.context data is null in the popup after the page loads - seems to get overwritten/deleted
    });
});
</code></pre>

<p>It doesn't work, so my next thought, wait until content is loaded</p>

<pre><code>var some contextData = {};
$(function() {
    $('#clickme').click(function() {
        var w = window.open('http://jsfiddle.net');
        w.onload = function() {
            //Never Fires
            w.contextData = contextData;

        }
    });
});
</code></pre>

<p>See <a href="http://jsfiddle.net/HNvn3/1/" rel="nofollow">this fiddle</a>. My onload method never fires.</p>

<p>This works:</p>

<pre><code>var some contextData = {};
    $(function() {
        $('#clickme').click(function() {
            var w = window.open('http://jsfiddle.net');
            setTimeout(function(){
                if(w.someVariableSetByThePageBeingLoaded) {
                    w.contextData = contextData;
                }
                else{
                    setTimeout(arguments.callee, 1);
                }

            }, 1);
        });
    });
</code></pre>

<p>But has obvious elegance problems (but is the current work around).</p>

<p>I know you can go the other way (have the popup call back to a method on the opener/parent, but this forces me to maintain some way of looking up context (and I have to pass the key to the context to the popup in the query string).  The current method lets me capture the context in a closure, making my popup a much more reusable piece of code.</p>

<p>I am not trying to do this cross domain - both the parent and popup are in the same domain, although the parent is an iframe (hard to test with jsfiddle).</p>

<p>Suggestions?</p>
