Today I updated a ticket I registered with the usually very agreeable MooTools js framework.

It is seemingly an issue with callback resources not existing when the callback is made, and the demo page is very simple; Click the link to open the popup, Trigger the ajax request in the popup, and close the window before the three seconds that the server script runs for is up.

This gives the error of $defined is not defined in MooTools 1.2 b2, an error that can be viewed with Firebug. I discovered the bug while working on a simple chat system in a popup, and my best shot at an explanation so far is that MooTools in the popup is being unloaded before the callback is fired – but then why is the callback fired at all? Slightly odd stuff.

UPDATE: The demo page for MooTools 1.11 is still up, and a slightly different error: $pick is not defined. MooTools AJAX bug