Setting window.onbeforeunload to undefined in IE8 causes" not implemented error

Question

            if(!$('fieldset.quote-step4').hasClass('show')) {
                window.onbeforeunload = function() {
                    return "Are you sure you want to leave the quote request page? This will reset the form.";
                }
            } else {
                window.onbeforeunload = undefined;
            }

I have the above in a script inside of a private function that's causing a "not implemented" error in ie8.

The specific line that causes the error is: window.onbeforeunload = undefined;

From what I've read in other questions window should be declared as a local variable to fix this issue-- but I'm not sure how.

Can anyone explain this bug to me and a possible solution?

Thank you!

Um, don't do that? What are you trying to do? – SLaks Jun 14 '13 at 19:18 — SLaks, Jun 14 '13 at 19:18
Edited question to show a little more detail – HandiworkNYC.com Jun 14 '13 at 19:19 — HandiworkNYC.com, Jun 14 '13 at 19:19

score 5 · Accepted Answer · answered Jun 14 '13 at 19:23

5

Try this:

$(window).on('beforeunload', function() {
   if($('fieldset.quote-step4').hasClass('show')) {
        return;
   }
   return "Are you sure you want to leave the quote request page? This will reset the form.";
});

And it is not the best idea to use DOM1 Handlers when jQuery is already on your page.

answered Jun 14 '13 at 19:23

FloydThreepwood

1,587
14
24

One problem with this solution... Now, Resharper nag me to return something ;) – Samuel Nov 19 '14 at 17:58

score 3 · Answer 2 · 2013-09-20T08:44:33.190

3

window.onbeforeunload = function(){};

edited Sep 20 '13 at 08:44

answered Sep 20 '13 at 08:37

score 1 · Answer 3 · answered Jun 14 '13 at 19:21

1

onbeforeunload is an event handler; apparently; IE8 doesn't like clearing it.

You can simply set it to a function that doesn't return anything.

answered Jun 14 '13 at 19:21

SLaks

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176
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Setting window.onbeforeunload to undefined in IE8 causes" not implemented error

3 Answers3