I am sure this has been discussed before; but I was not able to find such a discussion.

I noticed that if jQuery.isReady is true when ready( fn ) is called then the given callback is called synchronously. This bit me when I set up a mildly complicated class hierarchy in which I set one class to trigger an event in a ready( fn ) callback on instance initialization and set another class to listen for the same event. This all takes place in a single synchronous chunk of JavaScript where the initialization of one instance creates a new instance of the other.

Because that event registration takes places after the other class is initialized my code ends up missing the event. If ready( fn ) were called asynchronously in every case this would not be a problem.

I will cite the principle of least surprise to make the argument that ready( fn ) should behave as consistently as possible - that is it should invoke its callback asynchronously under all circumstances. Because it does not I 1) was surprised and 2) had to wrap a setTimout() around my event-triggering callback to handle the special case where an instance is initialized after the document is ready.

My proposed change is attached as a patch.