How to identify when the back button has been hit and do some js operation

Question

Is there any way that I can identify that the user clicked the "Back" button before this page? This is the none-existed example I have in my head:

window.onload = new function(e){
  if(e.type == "back"){
   //do some operation
  }
}

Is there a way to know that? Thanks

possible duplicate of [detect back button click in browser](http://stackoverflow.com/questions/6359327/detect-back-button-click-in-browser) — Darin Dimitrov, Jan 29 '12 at 15:29
What are you trying to do? Something tells me there's a better way then trying to catch a back button. Also, I don't believe this is possible, and [`onbeforeunload`](https://developer.mozilla.org/en/DOM/window.onbeforeunload) is really only dependable in IE. — Brad Christie, Jan 29 '12 at 15:30
short answer: **you cant**, in a easy or cross-browser way. Also read: [similar #1](http://stackoverflow.com/questions/2498672/detect-if-the-user-has-used-the-back-button) and [similar #2](http://stackoverflow.com/questions/55871/track-when-user-hits-back-button-on-the-browser) — c69, Jan 29 '12 at 15:33
I think the sentence "http is stateless" means something: in this case, you can't watch a *previous state* of a webpage (location.hash for example)., I agree with c69, this is not possible — Francesco Belladonna, Jan 29 '12 at 15:49

score 0 · Answer 1 · answered Jan 29 '12 at 17:38

0

Within your own site, and with a lot of work, you could do it with a cookie, but you would have to hook every link.

answered Jan 29 '12 at 17:38

Mark Robbins

score -2 · Answer 2 · answered Jan 29 '12 at 15:31

-2

yes, easily.

window.onbeforeunload = askConfirm;

function askConfirm(){

return "You have unsaved changes.";

}

answered Jan 29 '12 at 15:31

PaperCut

Yes, as Brad Christie said, it Does have a limited viewin browser support. – PaperCut Jan 29 '12 at 15:32
1

-1, question is about detecting if 'user clicked back-button **before** this page'. – c69 Jan 29 '12 at 15:35

2 Answers2