Need to prevent users going to the previous page, completely.
When I use the following code it works but it's not what I need exactly. When pressing the back button it says "Document Expired":
Response.Cache.SetExpires(DateTime.UtcNow.AddDays(-1));
Response.Cache.SetValidUntilExpires(false);
Response.Cache.SetRevalidation(HttpCacheRevalidation.AllCaches);
Response.Cache.SetCacheability(HttpCacheability.NoCache);
Response.Cache.SetNoStore();
Another idea - to open a new window without toolbar:
<script>
function PopupWithoutToolbar(link) {
var w = window.open(link.href,
link.target || "_blank",
'menubar=no,toolbar=no,location=no,directories=no,status=no,scrollbars=no,resizable=no,dependent,width=800,height=620,left=0,top=0');
return w ? false : true;
}
</script>
yahoo
But, still... If the user presses the backspace button on a keyboard he can go back. It seems that this approach is only for hiding and not disabling buttons.
Is there any way to simply ignore the back button?
I am not entirely sure if this will work, but you can try handling the event with javascript.
Like if you want to entirely disable the backspace button from allowing users to go back you can do like
$(window).on("keypress", function (e){
if(e.keycode == "backspace")
e.preventDefault();
})
I could figure out the keycode for backspace for you , but that isn't too hard to figure out. Also this uses jquery, but you can use just raw javascript. just wasn't sure what it would be offhand.
I'm using a slightly different solution:
history.pushState(null, null, location.href);
window.onpopstate = function () {
history.go(1);
}
Based on your post it sounds like your only issue is disabling the backspace button from allowing the user to go back.
Here's what I do for that using jquery. Still allows backspace to work inside enabled text editing inputs, where it should.
// Prevent the backspace key from navigating back.
$(document).unbind('keydown').bind('keydown', function (event) {
var doPrevent = false;
if (event.keyCode === 8) {
var d = event.srcElement || event.target;
if ((d.tagName.toUpperCase() === 'INPUT' && (d.type.toUpperCase() === 'TEXT' ||
d.type.toUpperCase() === 'PASSWORD' ||
d.type.toUpperCase() === 'FILE')) ||
d.tagName.toUpperCase() === 'TEXTAREA') {
doPrevent = d.readOnly || d.disabled;
}
else {
doPrevent = true;
}
}
if (doPrevent) {
event.preventDefault();
}
});
Simplest thing ever:
window.onhashchange = function (event) {
//blah blah blah
event.preventDefault();
return false;
}
You can handle the location domain etc from that (window.location) then cancel the event if you want in this case.
How to Detect Browser Back Button event - Cross Browser
To disable the back button in the browser you can use use the following code in your JavaScript on the page on which you want to disable the back button.
<script>
history.pushState(null, null, location.href);
window.onpopstate = function () {
history.go(1);
};
</script>
Iv been trying to figure out the best way to do this without much luck. I would like to do something if the user clicks back such as showing a custom dialog.
I have tried this which works to a certain extend:
var url = 'www.examples.com';
history.pushState(
{
pushStateUrl: url
},
url,
url
);
window.onpopstate = function() {
showDialog();
};
But it doesnt feel clean as it involves manipulating the browser history. Is there any better way to detect back without changing the history.
p.s. it does not have to work in all browsers. And preferably not using jquery.
Also beforeunload does not work in my case as I cannot show my own custom dialog.
this is a late response but I am posting in the intention of this could help to someone like me
add **beforeunload** event lister for your page when loaded
and remove it when submitting the form or whenever you want
step 1: var stayOnPage =function(){
confirm("Would you like to save this draft?");
if (!stayOnPage) {
history.back() or
// do your stuff
} else {
// do your stuff
}
}
window.addEventListener('beforeunload',stayOnPage);
step 2: remove event listener when you want
function onSubmitForm(){
window.removeEventListener('beforeunload',stayOnPage);
}
<button onclick="onSubmitForm()"> Submit </button>
if this doesn't work
change beforeunload to popstate
i.e
function onSubmitForm(){
window.addEventListener('popstate', stayOnPage);
}
Try this and it's found here
window.onbeforeunload = onBack;
function onBack(evt)
{
if (evt == undefined)
evt = window.event;
if ( (evt.clientX < 0) ||
(evt.clientY < 0) ||
(evt.clientX > document.body.clientWidth) ||
(evt.clientY > document.body.clientHeight)
)
{
alert('Unload from browser button press');
return "You clicked some browser button? Do you want to move away from this page?";
}
return undefined;
}
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?
Short, wrong answer:
You can do this by handling the beforeunload event and returning a non-null string:
window.addEventListener("beforeunload", function (e) {
var confirmationMessage = 'It looks like you have been editing something. '
+ 'If you leave before saving, your changes will be lost.';
(e || window.event).returnValue = confirmationMessage; //Gecko + IE
return confirmationMessage; //Gecko + Webkit, Safari, Chrome etc.
});
The problem with this approach is that submitting a form is also firing the unload event. This is fixed easily by adding the a flag that you're submitting a form:
var formSubmitting = false;
var setFormSubmitting = function() { formSubmitting = true; };
window.onload = function() {
window.addEventListener("beforeunload", function (e) {
if (formSubmitting) {
return undefined;
}
var confirmationMessage = 'It looks like you have been editing something. '
+ 'If you leave before saving, your changes will be lost.';
(e || window.event).returnValue = confirmationMessage; //Gecko + IE
return confirmationMessage; //Gecko + Webkit, Safari, Chrome etc.
});
};
Then calling the setter when submitting:
<form method="post" onsubmit="setFormSubmitting()">
<input type="submit" />
</form>
But read on...
Long, correct answer:
You also don't want to show this message when the user hasn't changed anything on your forms. One solution is to use the beforeunload event in combination with a "dirty" flag, which only triggers the prompt if it's really relevant.
var isDirty = function() { return false; }
window.onload = function() {
window.addEventListener("beforeunload", function (e) {
if (formSubmitting || !isDirty()) {
return undefined;
}
var confirmationMessage = 'It looks like you have been editing something. '
+ 'If you leave before saving, your changes will be lost.';
(e || window.event).returnValue = confirmationMessage; //Gecko + IE
return confirmationMessage; //Gecko + Webkit, Safari, Chrome etc.
});
};
Now to implement the isDirty method, there are various approaches.
You can use jQuery and form serialization, but this approach has some flaws. First you have to alter the code to work on any form ($("form").each() will do), but the greatest problem is that jQuery's serialize() will only work on named, non-disabled elements, so changing any disabled or unnamed element will not trigger the dirty flag. There are workarounds for that, like making controls readonly instead of enabling, serializing and then disabling the controls again.
So events seem the way to go. You can try listening for keypresses. This event has a few issues:
Won't trigger on checkboxes, radio buttons, or other elements that are being altered through mouse input.
Will trigger for irrelevant keypresses like the Ctrl key.
Won't trigger on values set through JavaScript code.
Won't trigger on cutting or pasting text through context menus.
Won't work for virtual inputs like datepickers or checkbox/radiobutton beautifiers which save their value in a hidden input through JavaScript.
The change event also doesn't trigger on values set from JavaScript code, so also won't work for virtual inputs.
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.
And when you want to implement more behavior, like ignoring certain elements, you'll have even more work to do.
Don't reinvent the wheel:
So before you think about implementing those solutions and all required workarounds, realize you're reinventing the wheel and you're prone to running into problems others have already solved for you.
If your application already uses jQuery, you may as well use tested, maintained code instead of rolling your own, and use a third-party library for all of this.
jquery.dirty (suggested by #troseman in the comments) provides functions for properly detecting whether a form has been changed or not, and preventing the user from leaving the page while displaying a prompt. It also has other useful functions like resetting the form, and setting the current state of the form as the "clean" state. Example usage:
$("#myForm").dirty({preventLeaving: true});
An older, currently abandoned project, is jQuery's Are You Sure? plugin, which also works great; see their demo page. Example usage:
<script src="jquery.are-you-sure.js"></script>
<script>
$(function() {
$('#myForm').areYouSure(
{
message: 'It looks like you have been editing something. '
+ 'If you leave before saving, your changes will be lost.'
}
);
});
</script>
Custom messages not supported everywhere
Do note that since 2011 already, Firefox 4 didn't support custom messages in this dialog. As of april 2016, Chrome 51 is being rolled out in which custom messages are also being removed.
Some alternatives exist elsewhere on this site, but I think a dialog like this is clear enough:
Do you want to leave this site?
Changes you made may not be saved.
Leave Stay
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.
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);
}
});
// clear modified inputs upon form submission
addEventListener("submit", (evt) => {
modified_inputs.clear();
// to prevent the warning from happening, it is advisable
// that you clear your form controls back to their default
// state with evt.target.reset() or form.reset() after submission
});
// warn before closing if any inputs are modified
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;
}
});
})();
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 :)
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.
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:
window.thisPage = window.thisPage || {};
window.thisPage.isDirty = false;
window.thisPage.closeEditorWarning = function (event) {
if (window.thisPage.isDirty)
return 'It looks like you have been editing something' +
' - if you leave before saving, then your changes will be lost.'
else
return undefined;
};
$("form").on('keyup', 'textarea', // You can use input[type=text] here as well.
function () {
window.thisPage.isDirty = true;
});
$("form").submit(function () {
QC.thisPage.isDirty = false;
});
window.onbeforeunload = window.thisPage.closeEditorWarning;
It's worth noting that IE11 seems to require that the closeEditorWarning function returns undefined for it not to show an alert.
The following one-liner has worked for me.
window.onbeforeunload = s => modified ? "" : null;
Just set modified to true or false depending on the state of your application.
You can use serialize() to create a URL encoded text string by serializing form values and check whether the form has changed beforeunload
$(document).ready(function(){
var form = $('#some-form'),
original = form.serialize()
form.submit(function(){
window.onbeforeunload = null
})
window.onbeforeunload = function(){
if (form.serialize() != original)
return 'Are you sure you want to leave?'
}
})
Refer this link https://coderwall.com/p/gny70a/alert-when-leaving-page-with-unsaved-form
Written by Vladimir Sidorenko
Following code works great. You need to reach your form elements' input changes via id attribute:
var somethingChanged=false;
$('#managerForm input').change(function() {
somethingChanged = true;
});
$(window).bind('beforeunload', function(e){
if(somethingChanged)
return "You made some changes and it's not saved?";
else
e=null; // i.e; if form state change show warning box, else don't show it.
});
});
Tested Eli Grey's universal solution, only worked after I simplified the code to
'use strict';
(() => {
const modified_inputs = new Set();
const defaultValue = 'defaultValue';
// store default values
addEventListener('beforeinput', evt => {
const target = evt.target;
if (!(defaultValue in target.dataset)) {
target.dataset[defaultValue] = ('' + (target.value || target.textContent)).trim();
}
});
// detect input modifications
addEventListener('input', evt => {
const target = evt.target;
let original = target.dataset[defaultValue];
let current = ('' + (target.value || target.textContent)).trim();
if (original !== current) {
if (!modified_inputs.has(target)) {
modified_inputs.add(target);
}
} else if (modified_inputs.has(target)) {
modified_inputs.delete(target);
}
});
addEventListener(
'saved',
function(e) {
modified_inputs.clear()
},
false
);
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;
}
});
})();
The modifications to his is deleted the usage of target[defaultValue] and only use target.dataset[defaultValue] to store the real default value.
And I added a 'saved' event listener where the 'saved' event will be triggered by yourself on your saving action succeeded.
But this 'universal' solution only works in browsers, not works in app's webview, for example, wechat browsers.
To make it work in wechat browsers(partially) also, another improvements again:
'use strict';
(() => {
const modified_inputs = new Set();
const defaultValue = 'defaultValue';
// store default values
addEventListener('beforeinput', evt => {
const target = evt.target;
if (!(defaultValue in target.dataset)) {
target.dataset[defaultValue] = ('' + (target.value || target.textContent)).trim();
}
});
// detect input modifications
addEventListener('input', evt => {
const target = evt.target;
let original = target.dataset[defaultValue];
let current = ('' + (target.value || target.textContent)).trim();
if (original !== current) {
if (!modified_inputs.has(target)) {
modified_inputs.add(target);
}
} else if (modified_inputs.has(target)) {
modified_inputs.delete(target);
}
if(modified_inputs.size){
const event = new Event('needSave')
window.dispatchEvent(event);
}
});
addEventListener(
'saved',
function(e) {
modified_inputs.clear()
},
false
);
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;
}
});
const ua = navigator.userAgent.toLowerCase();
if(/MicroMessenger/i.test(ua)) {
let pushed = false
addEventListener('needSave', evt => {
if(!pushed) {
pushHistory();
window.addEventListener("popstate", function(e) {
if(modified_inputs.size) {
var cfi = confirm('确定要离开当前页面嘛？' + JSON.stringify(e));
if (cfi) {
modified_inputs.clear()
history.go(-1)
}else{
e.preventDefault();
e.stopPropagation();
}
}
}, false);
}
pushed = true
});
}
function pushHistory() {
var state = {
title: document.title,
url: "#flag"
};
window.history.pushState(state, document.title, "#flag");
}
})();
var unsaved = false;
$(":input").change(function () {
unsaved = true;
});
function unloadPage() {
if (unsaved) {
alert("You have unsaved changes on this page. Do you want to leave this page and discard your changes or stay on this page?");
}
}
window.onbeforeunload = unloadPage;
Short answer:
let pageModified = true
window.addEventListener("beforeunload",
() => pageModified ? 'Close page without saving data?' : null
)
The solution by Eerik Sven Puudist ...
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.'
}
});
})
... spontaneously did the job for me in a complex object-oriented setting without any changes necessary.
The only change I applied was to refer to the concrete form (only one form per file) called "formForm" ('form' -> '#formForm'):
<form ... id="formForm" name="formForm" ...>
Especially well done is the fact that the submit button is being "left alone".
Additionally, it works for me also with the lastest version of Firefox (as of February 7th, 2019).
Adding to te idea of #codecaster
you could add this to every page with a form (in my case i use it in global way so only on forms would have this warn) change his function to
if ( formSubmitting || document.getElementsByTagName('form').length == 0)
Also put on forms submit including login and in cancel buttons links so when person press cancel or submit the form won't trigger the warn also in every page witouth a form...
<a class="btn btn-danger btn-md" href="back/url" onclick="setFormSubmitting()">Cancel</a>
You could check for a detailed explanation here:
http://techinvestigations.redexp.in/comparison-of-form-values-on-load-and-before-close/
The main code:
function formCompare(defaultValues, valuesOnClose) {
// Create arrays of property names
var aPropsFormLoad = Object.keys(defaultValues);
var aPropsFormClose = Object.keys(valuesOnClose);
// If number of properties is different,
// objects are not equivalent
if (aPropsFormLoad.length != aPropsFormClose.length) {
return false;
}
for (var i = 0; i < aPropsFormLoad.length; i++) {
var propName = aPropsFormLoad[i];
// If values of same property are not equal,
// objects are not equivalent
if (defaultValues[aPropsFormLoad]+"" !== valuesOnClose[aPropsFormLoad]+"") {
return false;
}
}
// If we made it this far, objects
// are considered equivalent
return true;
}
//add polyfill for older browsers, as explained on the link above
//use the block below on load
for(i=0; i < document.forms[0].elements.length; i++){
console.log("The field name is: " + document.forms[0].elements[i].name +
" and it’s value is: " + document.forms[0].elements[i].value );
aPropsFormLoad[i] = document.forms[0].elements[i].value;
}
//create a similar array on window unload event.
//and call the utility function
if (!formCompare(aPropsOnLoad, aPropsOnClose))
{
//perform action:
//ask user for confirmation or
//display message about changes made
}
I did it differently, sharing here so that someone can get help, tested only with Chrome.
I wanted to warn user before closing the tab only if there are some changes.
<input type="text" name="field" value="" class="onchange" />
var ischanged = false;
$('.onchange').change(function () {
ischanged = true;
});
window.onbeforeunload = function (e) {
if (ischanged) {
return "Make sure to save all changes.";
}
};
Works good, but got an-other issue, when i submit the form i get the unwanted warning, i saw lots of workaround on it, this is because onbeforeunload fires before onsubmit thats why we can't handle it in onsubmit event like onbeforeunload = null, but onclick event of submit button fires before these both events, so i updated the code
var isChanged = false;
var isSubmit = false;
window.onbeforeunload = function (e) {
if (isChanged && (!isSubmit)) {
return "Make sure to save all changes.";
}
};
$('#submitbutton').click(function () {
isSubmit = true;
});
$('.onchange').change(function () {
isChanged = true;
});
I made following code. It can compare changes in all fields (except those marked with .ignoreDirty class) or optionally for currently visible fields only. It can be reinitialized for new fields added by Javascript. From that reason I save not the form status but the status of each control.
/* Dirty warning for forms */
dirty = (skipHiddenOrNullToInit) => {
/* will return True if there are changes in form(s)
for first initialization you can use both: .dirty(null) or .dirty() (ignore its result)
.dirty(null) will (re)initialize all controls - in addititon use it after Save if you stay on same page
.dirty() will initialize new controls - in addititon use it if you add new fields with JavaScript
then
.dirty() (or: .dirty(false)) says if data are changed without regard to hidden fields
.dirty(true) says if data are changed with regard to hidden fields (ie. fields with .d-none or .hidden class)
controls with .ignoreDirty class will be skipped always
previous about .d-none, .hidden, .ignoreDirty applies to the control itself and all its ancestors
*/
let isDirty = false;
let skipSelectors = '.ignoreDirty';
if (skipHiddenOrNullToInit) {
skipSelectors += ', .d-none, .hidden'
} else if (skipHiddenOrNullToInit === undefined) {
skipHiddenOrNullToInit = false;
}
$('input, select').each(
function(_idx, el) {
if ($(el).prop('type') !== 'hidden') {
let dirtyInit = $(el).data('dirty-init');
if (skipHiddenOrNullToInit === null || dirtyInit === undefined) {
try {
isChromeAutofillEl = $(el).is(":-webkit-autofill");
} catch (error) {
isChromeAutofillEl = false;
}
if (isChromeAutofillEl && $(el).data('dirty-init') === undefined) {
setTimeout(function() { // otherwise problem with Chrome autofilled controls
$(el).data('dirty-init', $(el).val());
}, 200)
} else {
$(el).data('dirty-init', $(el).val());
}
} else if ($(el).closest(skipSelectors).length === 0 && dirtyInit !== $(el).val()) {
isDirty = true;
return false; // breaks jQuery .each
}
}
}
);
return isDirty;
}
I have additional troubles with Chrome autofill values because it is difficult to initizialize and have them loaded already. So I do not initialize on page load but in any focusin event. (But: Maybe there is still problem with control values changed by JavaScript.) I use following code which I call at page load:
let init_dirty = (ifStayFunc) => {
/* ifStayFunc: optional callback when user decides to stay on page
use .clearDirty class to avoid warning on some button, however:
if the button fires JavaScript do't use .clearDirty class and instead
use directly dirty(null) in code - to be sure it will run before window.location */
$('input, select').on('focusin', function(evt) {
if (!$('body').data('dirty_initialized')) {
dirty();
$('body').data('dirty_initialized', true);
}
});
window.addEventListener('beforeunload', (evt) => {
if (dirty(true)) {
if (ifStayFunc) {
ifStayFunc();
}
evt.preventDefault();
evt.returnValue = ''; // at least Google Chrome requires this
}
});
$('.clearDirty').on('click', function(evt) {
dirty(null);
});
};
So, I add the .clearDirty class to the buttons which provide Save and that way I prevent the warning in this case.
Callback ifStayFunc allows me to do something if user will Stay on Page while he is warned. Typically I can show additional Save Button (if I have still visible only some default/primary button, which makes Safe+SomethingMore - and I want allow Save withou this "SomethingMore").