When editing a page within my system, a user might decide to navigate to another website and in doing so could lose all the edits they have not saved.
I would like to intercept any attempt to go to another page and prompt the user to be sure they want this to happen since they could potentially lose their current work.
Gmail does this in a very similar way. For example, compose a new email, start typing into the message body and enter a new location in the address bar (say twitter.com or something). It will prompt asking "Are you sure?"
Ideas how to replicate this? I'm targeting IE8, but would like to be compatible with Firefox and Chrome also.
Similar to Ghommey's answer, but this also supports old versions of IE and Firefox.
window.onbeforeunload = function (e) {
var message = "Your confirmation message goes here.",
e = e || window.event;
// For IE and Firefox
if (e) {
e.returnValue = message;
}
// For Safari
return message;
};
See this article.
The feature you are looking for is the onbeforeunload
sample code:
<script language="JavaScript">
window.onbeforeunload = confirmExit;
function confirmExit()
{
return "You have attempted to leave this page. If you have made any changes to the fields without clicking the Save button, your changes will be lost. Are you sure you want to exit this page?";
}
</script>
Instead of an annoying confirmation popup, it would be nice to delay leaving just a bit (matter of milliseconds) to manage successfully posting the unsaved data to the server, which I managed for my site using writing dummy text to the console like this:
window.onbeforeunload=function(e){
// only take action (iterate) if my SCHEDULED_REQUEST object contains data
for (var key in SCHEDULED_REQUEST){
postRequest(SCHEDULED_REQUEST); // post and empty SCHEDULED_REQUEST object
for (var i=0;i<1000;i++){
// do something unnoticable but time consuming like writing a lot to console
console.log('buying some time to finish saving data');
};
break;
};
}; // no return string --> user will leave as normal but data is send to server
Edit:
See also Synchronous_AJAX and how to do that with jquery
I have users who have not been completing all required data.
<cfset unloadCheck=0>//a ColdFusion precheck in my page generation to see if unload check is needed
var erMsg="";
$(document).ready(function(){
<cfif q.myData eq "">
<cfset unloadCheck=1>
$("#myInput").change(function(){
verify(); //function elsewhere that checks all fields and populates erMsg with error messages for any fail(s)
if(erMsg=="") window.onbeforeunload = null; //all OK so let them pass
else window.onbeforeunload = confirmExit(); //borrowed from Jantimon above;
});
});
<cfif unloadCheck><!--- if any are outstanding, set the error message and the unload alert --->
verify();
window.onbeforeunload = confirmExit;
function confirmExit() {return "Data is incomplete for this Case:"+erMsg;}
</cfif>
Related
I need to warn users about unsaved changes before they leave a page (a pretty common problem).
window.onbeforeunload = handler
This works but it raises a default dialog with an irritating standard message that wraps my own text. I need to either completely replace the standard message, so my text is clear, or (even better) replace the entire dialog with a modal dialog using jQuery.
So far I have failed and I haven't found anyone else who seems to have an answer. Is it even possible?
Javascript in my page:
<script type="text/javascript">
window.onbeforeunload = closeIt;
</script>
The closeIt() function:
function closeIt()
{
if (changes == "true" || files == "true")
{
return "Here you can append a custom message to the default dialog.";
}
}
Using jQuery and jqModal I have tried this kind of thing (using a custom confirm dialog):
$(window).beforeunload(function () {
confirm('new message: ' + this.href + ' !', this.href);
return false;
});
which also doesn't work - I cannot seem to bind to the beforeunload event.
You can't modify the default dialogue for onbeforeunload, so your best bet may be to work with it.
window.onbeforeunload = function() {
return 'You have unsaved changes!';
}
Here's a reference to this from Microsoft:
When a string is assigned to the returnValue property of window.event, a dialog box appears that gives users the option to stay on the current page and retain the string that was assigned to it. The default statement that appears in the dialog box, "Are you sure you want to navigate away from this page? ... Press OK to continue, or Cancel to stay on the current page.", cannot be removed or altered.
The problem seems to be:
When onbeforeunload is called, it will take the return value of the handler as window.event.returnValue.
It will then parse the return value as a string (unless it is null).
Since false is parsed as a string, the dialogue box will fire, which will then pass an appropriate true/false.
The result is, there doesn't seem to be a way of assigning false to onbeforeunload to prevent it from the default dialogue.
Additional notes on jQuery:
Setting the event in jQuery may be problematic, as that allows other onbeforeunload events to occur as well. If you wish only for your unload event to occur I'd stick to plain ol' JavaScript for it.
jQuery doesn't have a shortcut for onbeforeunload so you'd have to use the generic bind syntax.
$(window).bind('beforeunload', function() {} );
Edit 09/04/2018: custom messages in onbeforeunload dialogs are deprecated since chrome-51 (cf: release note)
What worked for me, using jQuery and tested in IE8, Chrome and Firefox, is:
$(window).bind("beforeunload",function(event) {
if(hasChanged) return "You have unsaved changes";
});
It is important not to return anything if no prompt is required as there are differences between IE and other browser behaviours here.
While there isn't anything you can do about the box in some circumstances, you can intercept someone clicking on a link. For me, this was worth the effort for most scenarios and as a fallback, I've left the unload event.
I've used Boxy instead of the standard jQuery Dialog, it is available here: http://onehackoranother.com/projects/jquery/boxy/
$(':input').change(function() {
if(!is_dirty){
// When the user changes a field on this page, set our is_dirty flag.
is_dirty = true;
}
});
$('a').mousedown(function(e) {
if(is_dirty) {
// if the user navigates away from this page via an anchor link,
// popup a new boxy confirmation.
answer = Boxy.confirm("You have made some changes which you might want to save.");
}
});
window.onbeforeunload = function() {
if((is_dirty)&&(!answer)){
// call this if the box wasn't shown.
return 'You have made some changes which you might want to save.';
}
};
You could attach to another event, and filter more on what kind of anchor was clicked, but this works for me and what I want to do and serves as an example for others to use or improve. Thought I would share this for those wanting this solution.
I have cut out code, so this may not work as is.
1) Use onbeforeunload, not onunload.
2) The important thing is to avoid executing a return statement. I don't mean, by this, to avoid returning from your handler. You return all right, but you do it by ensuring that you reach the end of the function and DO NOT execute a return statement. Under these conditions the built-in standard dialog does not occur.
3) You can, if you use onbeforeunload, run an ajax call in your unbeforeunload handler to tidy up on the server, but it must be a synchronous one, and you have to wait for and handle the reply in your onbeforeunload handler (still respecting condition (2) above). I do this and it works fine. If you do a synchronous ajax call, everything is held up until the response comes back. If you do an asynchronous one, thinking that you don't care about the reply from the server, the page unload continues and your ajax call is aborted by this process - including a remote script if it's running.
This can't be done in chrome now to avoid spamming, refer to javascript onbeforeunload not showing custom message for more details.
Angular 9 approach:
constructor() {
window.addEventListener('beforeunload', (event: BeforeUnloadEvent) => {
if (this.generatedBarcodeIndex) {
event.preventDefault(); // for Firefox
event.returnValue = ''; // for Chrome
return '';
}
return false;
});
}
Browsers support and the removal of the custom message:
Chrome removed support for the custom message in ver 51 min
Opera removed support for the custom message in ver 38 min
Firefox removed support for the custom message in ver 44.0 min
Safari removed support for the custom message in ver 9.1 min
Try placing a return; instead of a message.. this is working most browsers for me.
(This only really prevents dialog's presents)
window.onbeforeunload = function(evt) {
//Your Extra Code
return;
}
You can detect which button (ok or cancel) pressed by user, because the onunload function called only when the user choise leaveing the page. Althoug in this funcion the possibilities is limited, because the DOM is being collapsed. You can run javascript, but the ajax POST doesn't do anything therefore you can't use this methode for automatic logout. But there is a solution for that. The window.open('logout.php') executed in the onunload funcion, so the user will logged out with a new window opening.
function onunload = (){
window.open('logout.php');
}
This code called when user leave the page or close the active window and user logged out by 'logout.php'.
The new window close immediately when logout php consist of code:
window.close();
I faced the same problem, I was ok to get its own dialog box with my message, but the problem I faced was :
1) It was giving message on all navigations I want it only for close click.
2) with my own confirmation message if user selects cancel it still shows the browser's default dialog box.
Following is the solutions code I found, which I wrote on my Master page.
function closeMe(evt) {
if (typeof evt == 'undefined') {
evt = window.event; }
if (evt && evt.clientX >= (window.event.screenX - 150) &&
evt.clientY >= -150 && evt.clientY <= 0) {
return "Do you want to log out of your current session?";
}
}
window.onbeforeunload = closeMe;
<script type="text/javascript">
window.onbeforeunload = function(evt) {
var message = 'Are you sure you want to leave?';
if (typeof evt == 'undefined') {
evt = window.event;
}
if (evt) {
evt.returnValue = message;
}
return message;
}
</script>
refer from http://www.codeprojectdownload.com
What about to use the specialized version of the "bind" command "one". Once the event handler executes the first time, it’s automatically removed as an event handler.
$(window).one("beforeunload", BeforeUnload);
Try this
$(window).bind('beforeunload', function (event) {
setTimeout(function () {
var retVal = confirm("Do you want to continue ?");
if (retVal == true) {
alert("User wants to continue!");
return true;
}
else {
window.stop();
return false;
}
});
return;
});
I need to call logout function on the close of browser window gets close. It's working fine in Chrome not working in IE and Safari.
I have tried the following code:
window.onbeforeunload = function (e) {
// Your logic to prepare for 'Stay on this Page' goes here
var evtobj = window.event ? event : e;
if (evtobj == e) {
//firefox
if (!evtobj.clientY) {
//server call
}
}
else {
//IE
if (evtobj.clientY < 0) {
//server call
}
}
//return "Please click 'Stay on this Page' and we will give you candy";
};
I have tried a few other ways but they didn't work. Please advise.
There is something wrong in your design, you SHOULDN'T rely on a client-side hook to perform logout. There are one billion of reasons why that event could not be executed. Just limit the onbeforeunload event to execute informational content and not critical actions.
By the way:
Don't return in your beforeunload event! This creates some issue in IE
Use window.sessionStorage to make some data last until the user closes the tab
Use session cookies to store your user's sensitive data like as tokens, and check if a user is logged on the server, and not on the client
I need to warn users about unsaved changes before they leave a page (a pretty common problem).
window.onbeforeunload = handler
This works but it raises a default dialog with an irritating standard message that wraps my own text. I need to either completely replace the standard message, so my text is clear, or (even better) replace the entire dialog with a modal dialog using jQuery.
So far I have failed and I haven't found anyone else who seems to have an answer. Is it even possible?
Javascript in my page:
<script type="text/javascript">
window.onbeforeunload = closeIt;
</script>
The closeIt() function:
function closeIt()
{
if (changes == "true" || files == "true")
{
return "Here you can append a custom message to the default dialog.";
}
}
Using jQuery and jqModal I have tried this kind of thing (using a custom confirm dialog):
$(window).beforeunload(function () {
confirm('new message: ' + this.href + ' !', this.href);
return false;
});
which also doesn't work - I cannot seem to bind to the beforeunload event.
You can't modify the default dialogue for onbeforeunload, so your best bet may be to work with it.
window.onbeforeunload = function() {
return 'You have unsaved changes!';
}
Here's a reference to this from Microsoft:
When a string is assigned to the returnValue property of window.event, a dialog box appears that gives users the option to stay on the current page and retain the string that was assigned to it. The default statement that appears in the dialog box, "Are you sure you want to navigate away from this page? ... Press OK to continue, or Cancel to stay on the current page.", cannot be removed or altered.
The problem seems to be:
When onbeforeunload is called, it will take the return value of the handler as window.event.returnValue.
It will then parse the return value as a string (unless it is null).
Since false is parsed as a string, the dialogue box will fire, which will then pass an appropriate true/false.
The result is, there doesn't seem to be a way of assigning false to onbeforeunload to prevent it from the default dialogue.
Additional notes on jQuery:
Setting the event in jQuery may be problematic, as that allows other onbeforeunload events to occur as well. If you wish only for your unload event to occur I'd stick to plain ol' JavaScript for it.
jQuery doesn't have a shortcut for onbeforeunload so you'd have to use the generic bind syntax.
$(window).bind('beforeunload', function() {} );
Edit 09/04/2018: custom messages in onbeforeunload dialogs are deprecated since chrome-51 (cf: release note)
What worked for me, using jQuery and tested in IE8, Chrome and Firefox, is:
$(window).bind("beforeunload",function(event) {
if(hasChanged) return "You have unsaved changes";
});
It is important not to return anything if no prompt is required as there are differences between IE and other browser behaviours here.
While there isn't anything you can do about the box in some circumstances, you can intercept someone clicking on a link. For me, this was worth the effort for most scenarios and as a fallback, I've left the unload event.
I've used Boxy instead of the standard jQuery Dialog, it is available here: http://onehackoranother.com/projects/jquery/boxy/
$(':input').change(function() {
if(!is_dirty){
// When the user changes a field on this page, set our is_dirty flag.
is_dirty = true;
}
});
$('a').mousedown(function(e) {
if(is_dirty) {
// if the user navigates away from this page via an anchor link,
// popup a new boxy confirmation.
answer = Boxy.confirm("You have made some changes which you might want to save.");
}
});
window.onbeforeunload = function() {
if((is_dirty)&&(!answer)){
// call this if the box wasn't shown.
return 'You have made some changes which you might want to save.';
}
};
You could attach to another event, and filter more on what kind of anchor was clicked, but this works for me and what I want to do and serves as an example for others to use or improve. Thought I would share this for those wanting this solution.
I have cut out code, so this may not work as is.
1) Use onbeforeunload, not onunload.
2) The important thing is to avoid executing a return statement. I don't mean, by this, to avoid returning from your handler. You return all right, but you do it by ensuring that you reach the end of the function and DO NOT execute a return statement. Under these conditions the built-in standard dialog does not occur.
3) You can, if you use onbeforeunload, run an ajax call in your unbeforeunload handler to tidy up on the server, but it must be a synchronous one, and you have to wait for and handle the reply in your onbeforeunload handler (still respecting condition (2) above). I do this and it works fine. If you do a synchronous ajax call, everything is held up until the response comes back. If you do an asynchronous one, thinking that you don't care about the reply from the server, the page unload continues and your ajax call is aborted by this process - including a remote script if it's running.
This can't be done in chrome now to avoid spamming, refer to javascript onbeforeunload not showing custom message for more details.
Angular 9 approach:
constructor() {
window.addEventListener('beforeunload', (event: BeforeUnloadEvent) => {
if (this.generatedBarcodeIndex) {
event.preventDefault(); // for Firefox
event.returnValue = ''; // for Chrome
return '';
}
return false;
});
}
Browsers support and the removal of the custom message:
Chrome removed support for the custom message in ver 51 min
Opera removed support for the custom message in ver 38 min
Firefox removed support for the custom message in ver 44.0 min
Safari removed support for the custom message in ver 9.1 min
Try placing a return; instead of a message.. this is working most browsers for me.
(This only really prevents dialog's presents)
window.onbeforeunload = function(evt) {
//Your Extra Code
return;
}
You can detect which button (ok or cancel) pressed by user, because the onunload function called only when the user choise leaveing the page. Althoug in this funcion the possibilities is limited, because the DOM is being collapsed. You can run javascript, but the ajax POST doesn't do anything therefore you can't use this methode for automatic logout. But there is a solution for that. The window.open('logout.php') executed in the onunload funcion, so the user will logged out with a new window opening.
function onunload = (){
window.open('logout.php');
}
This code called when user leave the page or close the active window and user logged out by 'logout.php'.
The new window close immediately when logout php consist of code:
window.close();
I faced the same problem, I was ok to get its own dialog box with my message, but the problem I faced was :
1) It was giving message on all navigations I want it only for close click.
2) with my own confirmation message if user selects cancel it still shows the browser's default dialog box.
Following is the solutions code I found, which I wrote on my Master page.
function closeMe(evt) {
if (typeof evt == 'undefined') {
evt = window.event; }
if (evt && evt.clientX >= (window.event.screenX - 150) &&
evt.clientY >= -150 && evt.clientY <= 0) {
return "Do you want to log out of your current session?";
}
}
window.onbeforeunload = closeMe;
<script type="text/javascript">
window.onbeforeunload = function(evt) {
var message = 'Are you sure you want to leave?';
if (typeof evt == 'undefined') {
evt = window.event;
}
if (evt) {
evt.returnValue = message;
}
return message;
}
</script>
refer from http://www.codeprojectdownload.com
What about to use the specialized version of the "bind" command "one". Once the event handler executes the first time, it’s automatically removed as an event handler.
$(window).one("beforeunload", BeforeUnload);
Try this
$(window).bind('beforeunload', function (event) {
setTimeout(function () {
var retVal = confirm("Do you want to continue ?");
if (retVal == true) {
alert("User wants to continue!");
return true;
}
else {
window.stop();
return false;
}
});
return;
});
I want to prompt user to either logout or stay on page as logged-in. I tried using the following code, but not able to find the correct solution:
window.onbeforeunload = function (e) {
var e = e || window.event;
// For IE and Firefox
if (e) {
e.returnValue = 'Any string';
}
alert(doLogout());
// For Safari
return 'Any string';
};
function doLogout(){
var r=confirm("Press a button!");
alert("confirmResponse: " + r);
return r;
}
When i tried closing the tab/window, it just asks for "This page is asking you to confirm that you want to leave - data you have entered may not be saved". In my code first confirm dialog should be popped up, which is not happening.
Any solutions ?
It won't do alert() because of security reasons. This tactic to prevent user from leaving the page was used too often by "bad guys of the internet" so most browser blocked it. Only thing you can do in onunload or onbeforeunload is pass a string that should be displayed to user, before he makes a decision to stay or leave page. You should put you message in place of 'Any string'. That should be sufficient for the user.
Obviously, window.onbeforeunload has encountered its fair share of problems with Chrome as I've seen from all the problems I've encountered. What's the most recent work around?
The only thing I've got even close to working is this:
window.onbeforeunload = function () { return "alert" };
However, if I substitute return "alert" with something like alert("blah"), I get nothing from Chrome.
I saw in this question that Google purposefully blocks this. Good for them... but what if I want to make an AJAX call when someone closes the window? In my case, I want to know when someone has left the chatroom on my website, signalled by the window closing.
I want to know if there's a way to either
(a): fix the window.onbeforeunload call so that I can put AJAX in there
or
(b): get some other way of determining that a window has closed in Chrome
Answer:
$(window).on('beforeunload', function() {
var x =logout();
return x;
});
function logout(){
jQuery.ajax({
});
return 1+3;
}
A little mix and match, but it worked for me. The 1+3 makes sure that the logout function is being called (you'll see 4 if it's successful on the popup when you try to leave).
As of Chrome 98.0.4758.109 and Edge 100.0.1185.29, Chromium has not met the standard. There is a bug report filed, but the review is abandoned.
Test with StackBlitz!
Chrome requires returnValue to be a non-null value whether set as the return value from the handler or by reference on the event object.
The standard states that prompting can be controlled by canceling the event or setting the return value to a non-null value.
The standard states that authors should use Event.preventDefault() instead of returnValue.
The standard states that the message shown to the user is not customizable.
window.addEventListener('beforeunload', function (e) {
// Cancel the event as stated by the standard.
e.preventDefault();
// Chrome requires returnValue to be set.
e.returnValue = '';
});
window.location = 'about:blank';
Here's a more straightforward approach.
$(window).on('beforeunload', function() {
return "You should keep this page open.";
});
The returned message can be anything you want, including the empty string if you have nothing to add to the message that Chrome already shows. The result looks like this:
According to MDN,
The function should assign a string value to the returnValue property
of the Event object and return the same string.
This is the following
window.addEventListener( 'beforeunload', function(ev) {
return ev.returnValue = 'My reason';
})
This solved my problem why it wasn't working in my app:
Note that the user must interact with the page somehow (clicking somewhere) before closing its window, otherwise beforeunload is ignored in order not prevent abuse.