IE doesn't execute my code 'onunload'

Question

I need to execute some code before leaving the browser, I implemented this:

    window.onbeforeunload = function () { return 'Are you sure?'; };
    window.onunload = function () { releaseLocking(); };

It works pretty well with Google Chrome. When closing GC: a message is shown,

if I click on the button 'stay on the page', nothing will happen. Perfect.
if I click on the button 'leave the page', the code under releaseLocking will be executed. Perfect.

I have problems with Internet Explorer.

if I click on the button 'stay on the page', nothing will happen. Perfect.
if I click on the button 'leave the page', the code under releaseLocking won't get executed.

Any idea?

I searched a lot but didnt found a solution.

Thanks.

UPDATE

var releaseLocking = function() {
    // Release only if lock is set on the current user
    if (transport().lockedById() == 5) { // 5 is dummy (Jean Dupont for testing)
        transport().lockedById(null);
        transport().lockedTime(null);
        return ctxTransport.saveChanges(SILENTSAVE);
    }
};

What does this have to do with jquery? If you used jquery your problem might go away. — Toby Allen, Jun 09 '13 at 18:51
I added jquery in tags before I am ok with a solution with jQuery if something is possible... — Bronzato, Jun 09 '13 at 18:52
What does `releaseLocking` do? How do you know it's not run? — John Dvorak, Jun 09 '13 at 18:53
try it like this `$(window).bind('beforeunload', function(){...});` — Ofir Hadad, Jun 09 '13 at 18:54
I know this releaseLocking is not run because I still have some data in my database which is removed in the releaseLocking. It is ok with GC. — Bronzato, Jun 09 '13 at 18:55
@Bronzato: Are you sure? Maybe just the `if()` condition is failing. Have you tried a little basic debugging, like putting a `console.log(...)` first thing inside the handler? — , Jun 09 '13 at 18:56
@Bronzato most likely `releaseLocking` is run, but the AJAX it fires isn't sent. — John Dvorak, Jun 09 '13 at 18:57
Ofar: yes I tried to set releaseLocking in the onbeforeunload. It works but that's not ok for me because user can refuse to qui the page... so I cannot run this code in this case. — Bronzato, Jun 09 '13 at 18:59
@Bronzato check this: http://stackoverflow.com/a/14746862/568414 — Ofir Hadad, Jun 09 '13 at 18:59
@Ofar: I have no way of changing from asynchronous to synchronous (no control on that). — Bronzato, Jun 09 '13 at 19:01
@Crazy yes I'm sure: even an alert in the `window.onunload` is not executed in IE. — Bronzato, Jun 09 '13 at 19:10

score 0 · Answer 1 · answered Jun 09 '13 at 19:13

It's seems IE have bug where the unload event wouldn't fire on a specific page on a site.

the unload event never fired since all the contents of the page hadn't finished loading before it's navigated to another page.

try stopping it before you unload

try this:

function fixUnload() {
    // Is there things still loading, then fake the unload event
    if (document.readyState == 'interactive') {
        function stop() {
            // Prevent memory leak
            document.detachEvent('onstop', stop);

            // Call unload handler
            unload();
        };

        // Fire unload when the currently loading page is stopped
        document.attachEvent('onstop', stop);

        // Remove onstop listener after a while to prevent the unload function
        // to execute if the user presses cancel in an onbeforeunload
        // confirm dialog and then presses the stop button in the browser
        window.setTimeout(function() {
            document.detachEvent('onstop', stop);
        }, 0);
    }
};

function unload() {
    alert('Unload event occured.');
};

window.attachEvent('onunload', unload);
window.attachEvent('onbeforeunload', fixUnload);

I'm pretty sure all the content of my page finished loading because I waited enough time (furthermore I work locally). — Bronzato, Jun 09 '13 at 19:16
Unfortunately it doesn't work: when I close the browser, it closed without any message. — Bronzato, Jun 09 '13 at 19:22

score 0 · Answer 2 · answered Jun 09 '13 at 19:29

0

These types of events are very unreliable.. what if the user's browser crashes (lol ie!) I was able to achieve the same outcome by using a heartbeat and polling the server every 20-30 seconds (or longer idk what your duration may be) and using that to handle the exiting event.. I had a locking mechanism in this app too.

Good luck.

answered Jun 09 '13 at 19:29

Zach Leighton

1,939
14
24

1

Do you mean you querry the server every 20-30 seconds to say 'hello, I'm still there, don't release the lock' ? – Bronzato Jun 09 '13 at 19:33
Exactly, you can extend it maybe to check for mouse or keyboard events to do a real idle timeout if you wish. Take a look at facebook's xhrs. – Zach Leighton Jun 09 '13 at 19:34

IE doesn't execute my code 'onunload'

2 Answers2