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 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;
});
Currently I am trying to build a website using ASP.NET MVC5.
I am stuck.
Issue: I want that when user goes to a particular page he/she should not be able to refresh the page, go back to the previous page, copy anything, print screen.
Have tried different solutions like the followings:
window.onload = function () {
if (typeof history.pushState === "function") {
history.pushState("jibberish", null, null);
window.onpopstate = function () {
history.pushState('newjibberish', null, null);
// Handle the back (or forward) buttons here
// Will NOT handle refresh, use onbeforeunload for this.
};
}
else {
var ignoreHashChange = true;
window.onhashchange = function () {
if (!ignoreHashChange) {
ignoreHashChange = true;
window.location.hash = Math.random();
// Detect and redirect change here
// Works in older FF and IE9
// * it does mess with your hash symbol (anchor?) pound sign
// delimiter on the end of the URL
}
else {
ignoreHashChange = false;
}
};
}
}
<script type="text/javascript">
window.onbeforeunload = function() {
return "Dude, are you sure you want to leave? Think of the kittens!";
}
</script>
<script type="text/javascript">
function disableF5(e) { if ((e.which || e.keyCode) == 116 || (e.which || e.keyCode) == 82) e.preventDefault(); };
$(document).ready(function(){
$(document).on("keydown", disableF5);
});
</script>
but nothing seem to work.
Please suggest.
You can do this with javascript using the parameters of window.open, for example
window.open('yourUrl','windowName','toolbar=no');
However I would not recommend this. Instead (based on your comment to lujcon's answer) your should design your controllers and view models correctly to prevent the issues you have described. For example, if the user has already answered a question, add a flag, then if they trey to post another answer for the same question, you can check the flag and prevent an update/display error message etc.
The only way I can think of to do what you ask with a web application is to make all of your "pages" a single view that loads the results from multiple Action methods using AJAX. If you load everything using JavaScript/AJAX, the browser won't be able to keep track of any page history.
Don't do that! Web based applications means freedom. User should do anything she/he wants. The question should be: how should I design my application to handle back and refresh button correctly (not disabling them). Disabling printing is useless as at any time user can make print-screen...
Could you please give me the best way to detect only window close event for all browsers by jQuery?
I mean clicking X button on the browser or window.close(), not meaning F5, form submission,
window.location or link.
I was looking for many threads but have not found the right way yet.
You can use :
$(window).unload(function() {
//do something
});
Unload() is deprecated in jQuery version 1.8, so if you use jQuery > 1.8 you can use even beforeunload instead.
The beforeunload event fires whenever the user leaves your page for any reason.
$(window).on("beforeunload", function() {
return confirm("Do you really want to close?");
});
Source Browser window close event
There is no specific event for capturing browser close event.
You can only capture on unload of the current page.
By this method, it will be effected while refreshing / navigating the current page.
Even calculating of X Y postion of the mouse event doesn't give you good result.
The unload() method was deprecated in jQuery version 1.8.
so if you are using versions older than 1.8
then use -
$(window).unload(function(){
alert("Goodbye!");
});
and if you are using 1.8 and higher
then use -
window.onbeforeunload = function() {
return "Bye now!";
};
hope this will work :-)
There is no specific event for capturing browser close event. But we can detect by the browser positions XY.
<script type="text/javascript">
$(document).ready(function() {
$(document).mousemove(function(e) {
if(e.pageY <= 5)
{
//this condition would occur when the user brings their cursor on address bar
//do something here
}
});
});
</script>
Combine the mousemove and window.onbeforeunload event :-
I used for set TimeOut for Audit Table.
$(document).ready(function () {
var checkCloseX = 0;
$(document).mousemove(function (e) {
if (e.pageY <= 5) {
checkCloseX = 1;
}
else { checkCloseX = 0; }
});
window.onbeforeunload = function (event) {
if (event) {
if (checkCloseX == 1) {
//alert('1111');
$.ajax({
type: "GET",
url: "Account/SetAuditHeaderTimeOut",
dataType: "json",
success: function (result) {
if (result != null) {
}
}
});
}
}
};
});
You can solve this problem with vanilla-Js:
Unload Basics
If you want to prompt or warn your user that they're going to close your page, you need to add code that sets .returnValue on a beforeunload event:
window.addEventListener('beforeunload', (event) => {
event.returnValue = `Are you sure you want to leave?`;
});
There's two things to remember.
Most modern browsers (Chrome 51+, Safari 9.1+ etc) will ignore what you say and just present a generic message. This prevents webpage authors from writing egregious messages, e.g., "Closing this tab will make your computer EXPLODE! 💣".
Showing a prompt isn't guaranteed. Just like playing audio on the web, browsers can ignore your request if a user hasn't interacted with your page. As a user, imagine opening and closing a tab that you never switch to—the background tab should not be able to prompt you that it's closing.
Optionally Show
You can add a simple condition to control whether to prompt your user by checking something within the event handler. This is fairly basic good practice, and could work well if you're just trying to warn a user that they've not finished filling out a single static form. For example:
let formChanged = false;
myForm.addEventListener('change', () => formChanged = true);
window.addEventListener('beforeunload', (event) => {
if (formChanged) {
event.returnValue = 'You have unfinished changes!';
}
});
But if your webpage or webapp is reasonably complex, these kinds of checks can get unwieldy. Sure, you can add more and more checks, but a good abstraction layer can help you and have other benefits—which I'll get to later. 👷♀️
Promises
So, let's build an abstraction layer around the Promise object, which represents the future result of work- like a response from a network fetch().
The traditional way folks are taught promises is to think of them as a single operation, perhaps requiring several steps- fetch from the server, update the DOM, save to a database. However, by sharing the Promise, other code can leverage it to watch when it's finished.
Pending Work
Here's an example of keeping track of pending work. By calling addToPendingWork with a Promise—for example, one returned from fetch()—we'll control whether to warn the user that they're going to unload your page.
const pendingOps = new Set();
window.addEventListener('beforeunload', (event) => {
if (pendingOps.size) {
event.returnValue = 'There is pending work. Sure you want to leave?';
}
});
function addToPendingWork(promise) {
pendingOps.add(promise);
const cleanup = () => pendingOps.delete(promise);
promise.then(cleanup).catch(cleanup);
}
Now, all you need to do is call addToPendingWork(p) on a promise, maybe one returned from fetch(). This works well for network operations and such- they naturally return a Promise because you're blocked on something outside the webpage's control.
more detail can view in this url:
https://dev.to/chromiumdev/sure-you-want-to-leavebrowser-beforeunload-event-4eg5
Hope that can solve your problem.
Hello Seniors (As I am new to Web Based Applications),
I was keen to implement or catching browser closing event.
Yes! I did it and successfully implemented it by using javascript{see code below}
but I have implemented it in a web page without MasterPage.
Now, as I am trying to implement it in a webpage with MASTERPAGE but in each post back...the event window.onunload is caught, which is giving me problems...
Is there any technique or logic to detect whether I can differentiate between a Close browser button and a page's post back event.
Please guide me...as I have to implement in a project as soon as possible....
thank you.
Ankit Srivastava
<script type="text/javascript">
function callAjax(webUrl, queryString)
{
var xmlHttpObject = null;
try
{
// Firefox, Opera 8.0+, Safari...
xmlHttpObject = new XMLHttpRequest();
}
catch(ex)
{
// Internet Explorer...
try
{
xmlHttpObject = new ActiveXObject('Msxml2.XMLHTTP');
}
catch(ex)
{
xmlHttpObject = new ActiveXObject('Microsoft.XMLHTTP');
}
}
if ( xmlHttpObject == null )
{
window.alert('AJAX is not available in this browser');
return;
}
xmlHttpObject.open("GET", webUrl + queryString, false);
xmlHttpObject.send();
return xmlText;
}
</script>
<script type="text/javascript">
var g_isPostBack = false;
window.onbeforeunload = check ()
function check()
{
if ( g_isPostBack == true )
return;
var closeMessage =
'You are exiting this page.\n' +
'If you have made changes without saving, your changes will be lost.\n' +
'Are you sure that you want to exit?';
if ( window.event )
{
// IE only...
window.event.returnValue = closeMessage;
}
else
{
// Other browsers...
return closeMessage;
}
g_isPostBack = false;
}
window.onunload = function ()
{
if ( g_isPostBack == true )
return;
var webUrl = 'LogOff.aspx';
var queryString = '?LogoffDatabase=Y&UserID=' + '<%# Session["loginId"] %>';
var returnCode = callAjax(webUrl, queryString);
}
</script>
There is no javascript event which differentiates between a browser being closed and the user navigating to another page (either via the back/forward button, or clicking a link, or any other navigation method). You can only tell when the current page is being unloaded. Having said that, I'm not sure why you'd even need to know the difference? Sounds like an XY problem to me.
The answer can be found on SO:
How to capture the browser window close event?
jQuery(window).bind("beforeunload", function(){return confirm("Do you really want to close?") })
and to prevent from confirming on submits:
jQuery('form').submit(function() {
jQuery(window).unbind("beforeunload");
...
});
First step: add global JavaScript variable called "_buttonClicked" which is initially set to false.
Second step: have every button click assign _buttonClicked value to true.. with jQuery it's one line, pure JavaScript is also few lines only.
Third step: in your function check _buttonClicked and if it's true, don't do anything.
EDIT: After quick look in your code I see you already have steps #1 and #3, so all you need is the second step, assign g_isPostBack as true when any submit button is clicked. Let me know if you need help implementing the code and if you can have jQuery.
If one wants to catch Log out when the browser is closed (by clicking on the cross), we can take the help of window events.
Two events will be helpful: onunload and onbeforeunload.
But the problem arises that the code will also work if you are navigating from one page to another as well as also when one
refreshes the page. We don't want our sessions to be clear and inserting the record of logging out while refreshing.
So the solution is if we distinguish the difference between closing and refreshing or navigating.
I got the solution:
Write 'onbeforeunload ="loadOut();"' within the body tag on master page.
Add the following function inside script in head section of master page :-
function loadOut() {
if ((window.event.clientX < 0) || (window.event.clientY < 0))
{
// calling the code behind method for inserting the log out into database
}
}
And its done. It is working for IE, please check for other browsers. Similarly you can detect the event if the window is closed
by pressing the combination of keys ALT+F4.
window.unload fires when we navigate from one page to another as well as when we click on close button of our browser,So to detect only browser close button you need to use flag.
var inFormOrLink;
$("a,:button,:submit").click(function () { inFormOrLink = true; });
$(":text").keydown(function (e) {
if (e.keyCode == 13) {
inFormOrLink = true;
}
})/// Sometime we submit form on pressing enter
$(window).bind("unload", function () {
if (!inFormOrLink) {
$.ajax({
type: 'POST',
async: false,
url: '/Account/Update/'
});
}
})