remove onbeforeunload event

[omerbutt]

Hi
i am working on a chat module in Yii and implemented the window close prompter function as follows

  $(document).ready(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.addEventListener)
                {
                        // Gecko
                        elm.addEventListener(evType, fn, useCapture);
                        return true;
                }
                else if (elm.attachEvent)
                {
                        // 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;
        }
 
 

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.

window.removeEventListener('onload',addListeners,true);
 

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

$(document).ready(function(){
            // Initialise window close prompter
            window.onbeforeunload = 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;
            }
 

and then in the logout method i overwrite the method

window.onbeforeunload = function () {
        // blank function do nothing
      }
 

[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 addEventListener/removeEventListener.

[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 readyStateChange 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