When exactly the $(document).ready callback is executed?

Question

Suppose that we attach a .click() handler to an anchor () tag in the $(document).ready callback. This handler will cancel the default action (following the

Answer 1

It depends on many things. If you have chunked encoding for example it is possible that a user will get a chunk but because the document is not ready yet the the listener will not be attached.

The jQuery ready event is the DOMContentLoaded event in W3C compliant browsers (standardized in the HTML5 specification), and some alternatives of this in others (like readystate in IE).

DOMContentLoaded (MDC)

Fired at the page's Document object when parsing of the document is finished. By the time this event fires, the page's DOM is ready.

Because this happens before rendering it would be a solid assumption that a callback executed after this event will be able to prevent user interaction on a not-ready page.

But as as Peter Michaux pointed out in his article due the the differences of how browsers implement this event "a robust technique for early enlivenment is not possible across the big four browsers."

So I would say that you can't rely 100% on jQuery ready event, but most of the time it will work just fine.