Back button event capturing in "Ask Question"

Question

The back button event isn't captured by window.onbeforeunload and isn't being handled by the onbeforeunload handler.

There are a few questions on Stack Overflow asking about capturing the back button with no good answer but yet if a user hits the browser's back button while composing a new question on Stack Overflow a message box asking him to if he's sure he wants to continue pops-up.

This message box is different between Chrome and Firefox and feels native.

So, what's behind the curtains?

How can I have the browser popup a message box which gives the user the option to stay on the current page (like with onbeforeunload)?

Answer 1

The back button event isn't captured by window.onbeforeunload and isn't being handled by the onbeforeunload handler.

Not true. Check this test case with plain JavaScript - back button triggers the onbeforeunload just fine. Checked with recent versions of all major browsers: Chrome 18, Firefox 11 and IE9. (Copy the link address, browse first to some other site then to the fiddle and hit the Back button)

So I fear your question is not really relevant - what you see is the browser native dialog.