1012573 - window.onbeforeunload not working

Status: RESOLVED WONTFIX

(Core :: DOM: Events, defect)

Description

[edu cielo]

User Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:31.0) Gecko/20100101 Firefox/31.0 (Beta/Release)
Build ID: 20140518004002

Steps to reproduce:

window.onbeforeunload = function () {
               alert("Hello I'm a Bug!");
            };


Actual results:

alert doesn't show. function doesnt executes


Expected results:

show an alert saying "Hello I'm a Bug!"

Comment 1

[Arkadiusz Michalski (Spirit)]

Working, but you try use alert(), which is blocked in most cases, like other pop-ups (https://bugzilla.mozilla.org/show_bug.cgi?id=969787). Try using just console.log:

window.onbeforeunload = function () {
 console.log("Hello I'm a Bug!");
};

But I see that still in some cases alert() is supported when use window.onbeforeunload.

And read this solution:
http://stackoverflow.com/questions/16517284/onunload-alert-error-ns-error-not-available

Comment 2

[Kohei Yoshino [:kohei]]

This is intended, see Bug 391834 and
https://developer.mozilla.org/en-US/Firefox/Releases/17/Site_compatibility#DOM

Comment 3

[edu cielo]

how about ajax request onbeforeunload event, will they fire?? because in my scenario, it doesn't fire in my controller. it doesn't fire the ajax request

Comment 4

[edu cielo]

in my scenario, it's quite weird. when i put breakpoints on the developer tools, the request is sent, and the whole process is executed, but when i don't use the developer tools, it doesn't goes to the controller.