Warn user before leaving web page with unsaved changes

jquery warn before leaving page
warn user before leaving web page with unsaved changes angular
confirm navigation leave this page javascript
are you sure you want to leave this page javascript disable
warn user before leaving page angular
javascript detect leaving page
window.onbeforeunload cancel event
jquery are you sure

I have some pages with forms in my application.

How can I secure the form in such a way that if someone navigates away or closes the browser tab, they should be prompted to to confirm they really want to leave the form with unsaved data?


Warn users before leaving a page with unsaved changes, This built-in prompt is not at all flexible, by design, to prevent rogue sites from actually preventing users from leaving their web sites. The following  When a user edits data in a desktop application such as a word processor, and then closes the application without saving that data, most applications will warn the user that they have unsaved changes and provide options for saving the data or to continue editing.


Check out the JavaScript onbeforeunload event. It's non-standard JavaScript introduced by Microsoft, however it works in most browsers and their onbeforeunload documentation has more information and examples.

Warn user before leaving web page with unsaved changes, This even will trigger whenever the user is trying to leave the page by <h1 id="​home">Warn before leaving the page</h1>; <script>; // Warning before leaving  Binding the input event to all inputs (and textareas and selects) on your page won’t work on older browsers and, like all event handling solutions mentioned above, doesn’t support undo. When a user changes a textbox and then undoes that, or checks and unchecks a checkbox, the form is still considered dirty.


via jquery

$('#form').data('serialize',$('#form').serialize()); // On load save form current state

$(window).bind('beforeunload', function(e){
    if($('#form').serialize()!=$('#form').data('serialize'))return true;
    else e=null; // i.e; if form state change show warning box, else don't show it.
});

You can Google JQuery Form Serialize function, this will collect all form inputs and save it in array. I guess this explain is enough :)

Prevent leaving the page using plain JavaScript, Dear, I have a form in which i have some fields what i want is that if a user navigates away from the page with unsaved changes then he will be  The user has a form with updated data, but this form is really a “sub form” which is entirely AJAX submitted. Here, we want to warn the user that the subform has pending changes before he/she posts the form, closes the tab or window, or hits the “Back” button on the browser. We’ll address the second scenario.


Universal solution requiring no configuration that automatically detects all input modification, including contenteditable elements:

"use strict";
(() => {
const modified_inputs = new Set;
const defaultValue = "defaultValue";
// store default values
addEventListener("beforeinput", (evt) => {
    const target = evt.target;
    if (!(defaultValue in target || defaultValue in target.dataset)) {
        target.dataset[defaultValue] = ("" + (target.value || target.textContent)).trim();
    }
});
// detect input modifications
addEventListener("input", (evt) => {
    const target = evt.target;
    let original;
    if (defaultValue in target) {
        original = target[defaultValue];
    } else {
        original = target.dataset[defaultValue];
    }
    if (original !== ("" + (target.value || target.textContent)).trim()) {
        if (!modified_inputs.has(target)) {
            modified_inputs.add(target);
        }
    } else if (modified_inputs.has(target)) {
        modified_inputs.delete(target);
    }
});
addEventListener("beforeunload", (evt) => {
    if (modified_inputs.size) {
        const unsaved_changes_warning = "Changes you made may not be saved.";
        evt.returnValue = unsaved_changes_warning;
        return unsaved_changes_warning;
    }
});
})();

How to Warn user before leaving web page with unsaved changes , The task is to show alert message like "Are you sure you want to leave this page" when user changed some data in form, but haven't submit it. Binding the input event to all inputs (and textareas and selects) on your page won't work on older browsers and, like all event handling solutions mentioned above, doesn't support undo. When a user changes a textbox and then undoes that, or checks and unchecks a checkbox, the form is still considered dirty.


Built on top of Wasim A.'s excellent idea to use serialization. The problem there was that the warning was also shown when the form was being submitted. This has been fixed here.

var isSubmitting = false

$(document).ready(function () {
    $('form').submit(function(){
        isSubmitting = true
    })

    $('form').data('initial-state', $('form').serialize());

    $(window).on('beforeunload', function() {
        if (!isSubmitting && $('form').serialize() != $('form').data('initial-state')){
            return 'You have unsaved changes which will not be saved.'
        }
    });
})

It has been tested in Chrome and IE 11.

Warning user before closing or leaving page with unsaved , Do you have some example of a warning popup so that users don't leave a FORM before SAVING their changes ? javascript stay Warn user before leaving web page with unsaved changes. save changes before leaving page (11) Based on the previous answers, and cobbled together from various places in stack overflow, here is the solution I came up with which handles the case when you actually want to submit your changes:


Alert when leaving page with unsaved form (Example), I want to warn user before leaving page with unsaved changes on salesforce standerd object. Thank You. jquery warn if leaving page without clicking the save button. The following code executes a warning if you change data on the page and then leave the page. I want that - except when the user presses the save button.


Popup, I have some pages with forms in my application. How can I secure the form in such a way that if someone navigates away or closes the browser  I want to write Jquery code in master file, so that if there if user changes page and there is any unsaved changes user should get alert. I got one answer from this: link However in most solution I will have to write code on all pages.


Warn user before leaving page with unsaved changes, For a web app to warn the user of unsaved changes requires knowing when the user is leaving the page, prompting the user and either saving the changes or stopping the user from leaving the page. The onunload event would seem to provide the first part of the solution. One problem however, is that there is no way to stop the onunload from happening.