remove onbeforeunload event

[omerbutt]

Hi
i am working on a chat module in Yii and implemented the window close prompter function as follows
[code=javascript]
$(document).rea dy(function(){
// Initialise window close prompter
addEvent(window , \'load\', addListeners, true);
});
/*WINDOW CLOSE PROMPTER CODE*/
// Cross browser event handling for IE 5+, NS6+ and Gecko
function addEvent(elm, evType, fn, useCapture)
{
if (elm.addEventLi stener)
{
// Gecko
elm.addEventLis tener(evType, fn, useCapture);
return true;
}
else if (elm.attachEven t)
{
// Internet Explorer
var r = elm.attachEvent (\'on\' + evType, fn);
return r;
}
else
{
// netscape?
elm[\'on\' + evType] = fn;
}
}

// Add Listeners
function addListeners(e)
{
// Before unload listener
addEvent(window , \'beforeunload\ ', exitAlert, false);
}

// Exit Alert
function exitAlert(e)
{

// default warning message
var msg = "You will lose information if it has not already been saved.";

// set event
if (!e) { e = window.event; }
if (e) { e.returnValue = msg; }

// return warning message
return msg;
}

[/code]
now the basic purpose was to prompt the user if he accidentally clicks the close window / TAB button but it prompts me every time when i have to redirect the page for example , if i click endChatSession button it should logout and redirect to the review meeting form but when ever it wil redirect or reload it will call the same prompt, i thought if i could be able to remove / unbind the listener i would be able to achieve what i am trying to do, so i added the following line in the endChatSession function but it is not unbind / removing the listener.
[code=javascript]
window.removeEv entListener('on load',addListen ers,true);
[/code]

any help will be appreciated
regards,
Omer Aslam

[Dormilich]

i thought if i could be able to remove / unbind the listener i would be able to achieve what i am trying to do, so i added the following line in the endChatSession function but it is not unbind / removing the listener.

that’s the wrong call, that would only remove the listener that is called onload not any listener defined elsewhere. you need to undo line #32.

[omerbutt]

Hope i am getting you write but then it wont be calling the prompt on close if i remove it.
regards,
Omer Aslam

[Dormilich]

isn’t that what you wanted?

[omerbutt]

No i wanted to prompt whenever user clicks accidently on the window or TAB close button but not when i intentionally want to redirect like in the logout method, i rewrote the whole scenario now it is done see below hope this helps some one out
[code=javascript]
$(document).rea dy(function(){
// Initialise window close prompter
window.onbefore unload = function (evt) {
var message = \'Are you sure you want to leave this page?\';
if (typeof evt == \'undefined\') {
evt = window.event;
}
if (evt ) {
evt.returnValue = message;
}
return message;
}
[/code]
and then in the logout method i overwrite the method
[code=javascript]
window.onbefore unload = function () {
// blank function do nothing
}
[/code]

[omerbutt]

the simplest one was rather the right thing to do. cheers.
regards,
Omer Aslam

[Dormilich]

just a question, when you immediately remove the beforeunload handler, why defining it in the first place?

besides that, what you have done is exactly what I said in post #2. only that you used onevent properties instead of addEventListene r/removeEventList ener.

[omerbutt]

no i dont immediately remove it the document.ready part run when chat loads, i actually am using it to prevent any accidental close of the chat window or tab , and the unloading part is actually a part of the logout method , where i throw an ajax call update tables and then in readyStateChang e method redirect the page to the couch ratings form that the client has to fill up after his Text Chat appointment, at this point the prompt that i had loaded on the page load appears and halts the redirection, apart from it the appointment has a dedicated time frame after which the user would be automatically be logged out and redirected to the couch ratings form, hope i answered what you were asking.
regards,
Omer Aslam