launch confirm dialog if user changes input without saving - javascript

I need to implement in JS a warning if a user changes an input field in a form without saving. The expected behavior is that I make a change into the input and if I try to close the window the confirm dialog appears.
However, what actually happens is when I close the window, the window closes and the dialog does not appear.
I'm referencing the following resources:
Warn user before leaving web page with unsaved changes
JavaScript before leaving the page
This is what I have currently:
var formInputChanged = false;
$(function() {
// activate modal is field is edited
$(".account-settings-form input").on("input", function() {
window.formInputChanged = true;
});
$("input[value='Cancel']").click(function() {
window.formInputChanged = false;
});
window.addEventListener('beforeunload', (event) => {
if (window.formInputChanged) {
confirm("You have unsaved changes");
}
});
});
I have that variable set globally so as far a I understand, should be fully accessible and I'm assigning it to the window in the functions.
I can see in the console.log() that formInputChanged is the correct value.
https://developer.mozilla.org/en-US/docs/Web/API/Window/beforeunload_event
This event enables a web page to trigger a confirmation dialog asking
the user if they really want to leave the page. If the user confirms,
the browser navigates to the new page, otherwise it cancels the
navigation.
What does "leave the page" mean? Back button? X out? Is it an event listener issue?
According to the specification, to show the confirmation dialog an
event handler should call preventDefault() on the event.
I have that in place so that doesn't seem to be the issue...
Why doesn't the confirm modal launch?
Here is a full JS Fiddle demo: https://jsfiddle.net/g6wjrcae/

In the conditional you add:
event.returnValue = "";
return "";
So:
window.addEventListener('beforeunload', (event) => {
event.preventDefault();
if (window.formInputChanged) {
event.returnValue = "";
return "";
}
});

Try this in handler for "beforeunload"
window.addEventListener("beforeunload", function (e) {
if(formInputChanged) {
var confirmationMessage = "You have unsaved changes";
(e || window.event).returnValue = confirmationMessage; //Gecko + IE
return confirmationMessage; //Gecko + Webkit, Safari, Chrome etc.
}
});
I believe confirm("You have unsaved changes"); is where your issue is.

Related

Alert on exit the browser and closing the tab

I tried onbeforeunload as it requires once user-interaction to call, is there any way to call an event without user-interaction as the user exit the browser after it opens the application tab.
Or Any other solution without using onbeforeunload that prevents the user to exit the browser.
window.onbeforeunload = function (event) {
var message = 'Important: Please click on \'Save\' button to leave this page.';
if (typeof event == 'undefined') {
event = window.event;
}
if (event) {
event.returnValue = message;
}
return message;
};
$(document).ready(function(){
$(".label").click(function(){
alert('label');
window.onbeforeunload = null;
}
);
$(".new_cont").click(function(){
alert('new_cont');
window.onbeforeunload = null;
}
);
})
In both FireFox and Chrome you need at least one interaction with the page.
Since this feature is to avoid losing data which was entered by the user, if no action happened on the page, then the user did not enter any data.
This is because the onbeforeunload is attached to the 's window object, and when you unload the main page, this event won't fire unless you had focus on this iframe.
<script type="text/javascript">
window.onbeforeunload = function () {
return "Did you save your stuff?"
}
For reference https://developer.mozilla.org/en-US/docs/Web/API/WindowEventHandlers/onbeforeunload

Onbeforeunload don't prompt confirmation for page reload

I'm adding an event listener for onbeforeunload that prompts a confirmation message when the user tries to leave the page.
Unfortunately, I don't want the confirmation message to appear when the user tries to reload the page.
How do I do this?
Here's what I have so far:
window.onbeforeunload = function() {
return "";
}
It's completely possible1.
You can listen for the keydown event and check whether the user reloaded the page via the shortcut Ctrl + R. If so, you can set a variable (in our case, isReload) to true and set a timeout to set it back to false after, say, 100 milliseconds.
When the onbeforeunload event fires, check whether isReload is true. If it is, return null to allow the browser to close. Otherwise, return "" to prompt a confirmation.
Demo:
var isReload = false;
document.addEventListener('keydown', function(e){
if(e.ctrlKey && e.keyCode == 82){
isReload = true;
setTimeout(function(){isReload = false}, 100);
}
})
window.onbeforeunload = function(){
if(!isReload){
return "";
}else{
return null;
}
}
1 This only works for the shortcut. You can't differentiate between closure/reload if the user manually clicks the reload button

JavaScript confirm dialog box keeps on regenerating on cancel event

SCENARIO: I just want to warn user on window change; so I've used jQuery's window blur & JavaScript's confirm dialogue box. When user will click OK button the application will redirect to another page & when user will click CANCEL button nothing will happen. He can continue his work on the same page.
ISSUE: OK button is working perfectly but when I click on the CANCEL button, the browser keeps on regenerating the dialogue box. How do I stop that?
CODE:
$(window).blur( function (e) {
var closeWindow = window.confirm("Your test will be cancelled if you switch the tabs.");
if (closeWindow) {
// redirect to another page
}
else {
// do nothing.
}
});
As #ROAL explained, the first blur event is because of actual blur, and rest are because of the browser trying to move away from the tab. A simple solution for this would be to use a flag to distinguish between the user generated event and the browser generated event. Give this a try:
var manualCancellation = false;
$(window).blur( function (e) {
if(!manualCancellation ){
var closeWindow = window.confirm("Your test will be cancelled if you switch the tabs.");
console.log(e);
if (closeWindow) {
// redirect to another page
}
else {
manualCancellation = true;
// do nothing.
}
} else {
// Reset the value of manualCancellation so that the event is fired the next time.
manualCancellation = false;
}
});

Prevent double submission with prevent window event issue

I'm using the following function to prevent double submissions:
$("#form").submit(function () {
var form = $(this);
form.find("input[type=submit]").attr("disabled", "disabled")
form.find("input[type=submit]").attr("value", "Processing");
});
It works fine, but then I have the following code which triggers an alert to avoid accidentally leaving the page:
function goodbye(e) {
if(!e) e = window.event;
//e.cancelBubble is supported by IE - this will kill the bubbling process.
e.cancelBubble = true;
e.returnValue = '¿DO YOU REALLY WANT TO LEAVE THIS PAGE?'; //This is displayed on the dialog
//e.stopPropagation works in Firefox.
if (e.stopPropagation) {
e.stopPropagation();
e.preventDefault();
}
}
window.onbeforeunload=goodbye;
The problem is if the user clicks submit and the realizes he didnt want to leave the page and clicks on stay on this page instead, the submit button is still disabled.
How could I re-enable it upon clicking stay on this page?
Thanks!
The button problem
You want to disable and enable the submit button so you know you going to touch the same kind of function and object twice, it is better to make advantage out of this in a function
function disableSubmit(form, enabled){
var submit = form.find("input[type=submit]"),
dataVar = enabled !== true ? "processing-message" : "send-message",
message = submit.data(dataVar);
submit.prop('disabled', (enabled !== true) );
submit.val(message);
}
I could make it even more generic for using it on each form. But the message in the button will display whatever you put in the data-attribute.
Cancel Submit
There is a problem with cancellation of an onbeforeunload event; there is no callback for it. The solution I came with is using a timeout. Since you don't know if the person canceled or not, I think 2 seconds is enough for the page to submit.
You have to have 2 seconds patient to get the submit button enabled again. But you can adjust it all you want of course
if (e.stopPropagation) {
setTimeout(function () {
disableSubmit(formObject, true);
}, 2000);
e.stopPropagation();
e.preventDefault();
}
The JSFiddle example

save user email before leaving page

On the cart page of my website, I have to intercept the user leaving the page and ask them if they want to save their cart via email.
I guess I have to use the event "beforeunload" to intercept the user leaving the page, but then I have two problems:
How to exclude from the "beforeunload" trigger the click on the link to proceed with the payment?
How to prompt a small form where I can ask for his email (to be used somehow later) and then proceed with the unload of the page?
For excluding on the link to proceed with the payment, you can do this :-
window.onbeforeunload = function() {
return "You're leaving the site.";
};
$(document).ready(function() {
$('a[rel!=ext]').click(function() { window.onbeforeunload = null; });
$('form').submit(function() { window.onbeforeunload = null; });
});
The only thing u can do is making a default browser messagebox appears...
window.onbeforeunload = foo;
function foo(e) {
if (!e) e = window.event;
//e.cancelBubble is supported by IE - this will kill the bubbling process.
e.cancelBubble = true;
e.returnValue = 'You sure you want to leave?'; //This is displayed on the dialog
//e.stopPropagation works in Firefox.
if (e.stopPropagation) {
e.stopPropagation();
e.preventDefault();
}
}

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