How to reenable event.preventDefault? - javascript

I have a web page which I have prevented the default action on all submit buttons, however I would like to re-enable default submit action on a button how can I do this?
I am currently preventing the default action using the following:
$("form").bind("submit", function(e){
e.preventDefault();
});
I have successfully done this using the following:
$(document).ready(function(){
$("form:not('#press')").bind("submit", function(e){
e.preventDefault();
});
But can I do this dynamically when the button is clicked?

You would have to unbind the event and either rebind to a separate event that does not preventDefault or just call the default event yourself later in the method after unbinding.
There is no magical event.cancelled=false;
As requested
$('form').submit( function(ev){
ev.preventDefault();
//later you decide you want to submit
$(this).unbind('submit').submit()
});

Either you do what redsquare proposes with this code:
function preventDefault(e) {
e.preventDefault();
}
$("form").bind("submit", preventDefault);
// later, now switching back
$("form#foo").unbind("submit", preventDefault);
Or you assign a form attribute whenever submission is allowed. Something like this:
function preventDefault(e) {
if (event.currentTarget.allowDefault) {
return;
}
e.preventDefault();
}
$("form").bind("submit", preventDefault);
// later, now allowing submissions on the form
$("form#foo").get(0).allowDefault = true;

function(e){ e.preventDefault();
and its opposite
function(e){ return true; }
cheers!

$('form').submit( function(e){
e.preventDefault();
//later you decide you want to submit
$(this).trigger('submit'); or $(this).trigger('anyEvent');

With async actions (timers, ajax) you can override the property isDefaultPrevented like this:
$('a').click(function(evt){
e.preventDefault();
// in async handler (ajax/timer) do these actions:
setTimeout(function(){
// override prevented flag to prevent jquery from discarding event
evt.isDefaultPrevented = function(){ return false; }
// retrigger with the exactly same event data
$(this).trigger(evt);
}, 1000);
}
This is most complete way of retriggering the event with the exactly same data.

I had a similar problem recently. I had a form and PHP function that to be run once the form is submitted. However, I needed to run a javascript first.
// This variable is used in order to determine if we already did our js fun
var window.alreadyClicked = "NO"
$("form:not('#press')").bind("submit", function(e){
// Check if we already run js part
if(window.alreadyClicked == "NO"){
// Prevent page refresh
e.preventDefault();
// Change variable value so next time we submit the form the js wont run
window.alreadyClicked = "YES"
// Here is your actual js you need to run before doing the php part
xxxxxxxxxx
// Submit the form again but since we changed the value of our variable js wont be run and page can reload (and php can do whatever you told it to)
$("form:not('#press')").submit()
}
});

You can re-activate the actions by adding
this.delegateEvents(); // Re-activates the events for all the buttons
If you add it to the render function of a backbone js view, then you can use event.preventDefault() as required.

Related

preventDefault works only once?

this trigger works correctly ONE time. If it fires again, it just refreshes my page, so I’m guessing that the preventDefault isn’t working. Am I missing something?
function watchForm() {
$(‘form’).submit(event => { //listening for event on the form pop-up menu
event.preventDefault(); //suppresses browser from going to a linked page.
$(’#js-error-message’).empty();
let searchState = $(’#js-stateMenuForm :selected’).val();
getParks(searchState); //calls getParks function.
});
}
Rewrite your function to this below and see if it works:
function watchForm(){
// for every form on the page
$('form').on('submit', function(e){
// empty the error element
$('#js-error-message').empty();
var searchState = $('#js-stateMenuForm :selected').val();
// call the function that uses the value you are looking forward to.
getParks(searchState);
// where e is the event
e.preventDefault();
return false; // force return of the form's submission
});
}
Also, you can check this post: Jquery .on() submit event

Javascript return false; is not cancelling a form submit for another .submit jQuery call

I have this jQuery function injected on every page in order to disable submit buttons after they are clicked.
$('form').submit(function () {
var btn = $('input[type=submit]', this);
disableButtonOrLink.disableSubmit(btn);
btn = $('button[type=submit]', this);
disableButtonOrLink.disableSubmit(btn);
});
The problem is that I also have some backend validation that is sometimes attached to the form in the the shape of something like this
<form action="someAction" method="post" name="someForm" class="form"
onsubmit="var invalid=false;
invalid=someAction();
if(invalid){return false;}"
id="someForm">
The issue I am having that is occurs is that the ('form').submit action is always being called after the return false. The form isn't actually being submitted due to the return false; however this jQuery function is still being called after. Is there anyway to prevent this .submit from being called?
Just to clarify exactly what is happening:
The onSubmit on the form is being called;
The return false section is being hit and properly canceling the submit;
The ('form').submit is still being called after the onSubmit completes as if the form's submit wasn't canceled and is disabling buttons.
I would like to prevent the last step from occurring.
You can use JQuery to find those buttons inside form and use a method from preventing stuff that they normally do.
Example:
$("form button").on('click', function(e){
e.preventDefault();
});
I would probably try something like this
$('#someForm').on('submit', function(e) {
if ($(this).data('some-action')) {
e.preventDefault();
return false;
}
//... then disable buttons, etc
});
In this case you need to add the attribute data-some-action to the form, evaluated with whatever backend validation you are doing.
UPDATE
$('#someForm').on('submit', function(e) {
if ($(this).data('some-action') == 'error-message') {
e.preventDefault();
alert('error!');
return false;
}
if ($(this).data('some-action') == 'reload') {
e.preventDefault();
document.location.reload(true);
}
//... then disable buttons, etc
});

jQuery form getting submitted multiple times

I've made a simple lightbox implementation in my code. By Clicking on #makePayment link a lightbox is opened, and within that lightbox there is a form. When user clicks on #paymentDetailsConfrimLB to submit the form, I've just displayed an alert.
Before I explain the problem, please have a look at the code I've written:
$("#makePayment").click(function() {
$("body").addClass("modalPrint");
var lb = new LightBox("paymentDetailsLB", "675", "500");
lb.htmlObjRef.style.height = "auto";
lb.show();
$("#paymentDetailsCloseLB, .hideBox").click(function() {
$("body").removeClass("modalPrint");
lb.hide();
});//paymentDetailsCloseLB
$("#paymentDetailsConfrimLB").click(function( event ) {
alert('form submission happened.');
event.preventDefault();
return false;
});//paymentDetailsConfrimLB
return false;
});//makePayment
Problem is, when I first load the page, and open the lightbox, and click the submit button, the alert is shown once (as it should), but if I close the lightbox, re-open it, and then submit the form, it is submitted twice and alert is shown twice. Similarly if I again close and re-open the lightbox, upon form submission the alert shows up 3 times, and it goes on like this.
Any idea on how I can resolve this?
Other than Kavin's approach, another solution also worked for me. I just added this line immediately after the event.preventDefault() method:
event.stopImmediatePropagation()
And it resolved the issue.
You're setting click callback every time you open lightbox. Try to move click callbacks out of #makePayment:
$("#makePayment").click(function() {
$("body").addClass("modalPrint");
var lb = new LightBox("paymentDetailsLB", "675", "500");
lb.htmlObjRef.style.height = "auto";
lb.show();
return false;
});//makePayment
$("#paymentDetailsCloseLB, .hideBox").click(function() {
$("body").removeClass("modalPrint");
lb.hide();
});//paymentDetailsCloseLB
$("#paymentDetailsConfrimLB").click(function( event ) {
alert('form submission happened.');
event.preventDefault();
return false;
});//paymentDetailsConfrimLB
You're binding a new handlers every time the submit button is clicked. You only need to define a handler once, and it will be executed whenever that action occurs. Otherwise, each handler you bind will execute.
If you absolutely needed to bind the handlers the way you are, then you could also use .one, which will only bind the handler the first time for each element.
jQuery .one() documentation
Attach a handler to an event for the elements. The handler is executed
at most once per element per event type.
Try something like this.
$(document).on('click', '#makePayment', function() {
$("body").addClass("modalPrint");
var lb = new LightBox("paymentDetailsLB", "675", "500");
lb.htmlObjRef.style.height = "auto";
lb.show();
return false;
}).on('click', '#paymentDetailsCloseLB, .hideBox', function() {
$("body").removeClass("modalPrint");
lb.hide()
}).on('click', '#paymentDetailsConfrimLB', function() {
alert('form submission happened.');
event.preventDefault();
return false;
});
The problem is:
$("#paymentDetailsConfrimLB").click(function( event ) {
alert('form submission happened.');
event.preventDefault();
return false;
});//paymentDetailsConfrimLB
it adds to the click queue, so to speak. So if you add multiple click events to something, all of them get added and all of them run by default. You don't notice it because all your other functions don't matter about being run multiple times.
A way to solve this is to put a check within the function.
$("#paymentDetailsCloseLB, .hideBox").click(function() {
$("body").removeClass("modalPrint");
lb.hide();
});//paymentDetailsCloseLB
pDCLB=$("#paymentDetailsConfrimLB");
if(!pDCLB.attr('alertc')); //check if the attribute exists, if not, we've never been here before.
pDCLB.attr('alertc',1); //adds the attribute so we can check it later.
$("#paymentDetailsConfrimLB").click(function( event ) {
alert('form submission happened.');
event.preventDefault();
return false;
});//paymentDetailsConfrimLB
}

Preventing multiple clicks on button

I have following jQuery code to prevent double clicking a button. It works fine. I am using Page_ClientValidate() to ensure that the double click is prevented only if the page is valid. [If there are validation errors the flag should not be set as there is no postback to server started]
Is there a better method to prevent the second click on the button before the page loads back?
Can we set the flag isOperationInProgress = yesIndicator only if the page is causing a postback to server? Is there a suitable event for it that will be called before the user can click on the button for the second time?
Note: I am looking for a solution that won't require any new API
Note: This question is not a duplicate. Here I am trying to avoid the use of Page_ClientValidate(). Also I am looking for an event where I can move the code so that I need not use Page_ClientValidate()
Note: No ajax involved in my scenario. The ASP.Net form will be submitted to server synchronously. The button click event in javascript is only for preventing double click. The form submission is synchronous using ASP.Net.
Present Code
$(document).ready(function () {
var noIndicator = 'No';
var yesIndicator = 'Yes';
var isOperationInProgress = 'No';
$('.applicationButton').click(function (e) {
// Prevent button from double click
var isPageValid = Page_ClientValidate();
if (isPageValid) {
if (isOperationInProgress == noIndicator) {
isOperationInProgress = yesIndicator;
} else {
e.preventDefault();
}
}
});
});
References:
Validator causes improper behavior for double click check
Whether to use Page_IsValid or Page_ClientValidate() (for Client Side Events)
Note by #Peter Ivan in the above references:
calling Page_ClientValidate() repeatedly may cause the page to be too obtrusive (multiple alerts etc.).
I found this solution that is simple and worked for me:
<form ...>
<input ...>
<button ... onclick="this.disabled=true;this.value='Submitting...'; this.form.submit();">
</form>
This solution was found in:
Original solution
JS provides an easy solution by using the event properties:
$('selector').click(function(event) {
if(!event.detail || event.detail == 1){//activate on first click only to avoid hiding again on multiple clicks
// code here. // It will execute only once on multiple clicks
}
});
disable the button on click, enable it after the operation completes
$(document).ready(function () {
$("#btn").on("click", function() {
$(this).attr("disabled", "disabled");
doWork(); //this method contains your logic
});
});
function doWork() {
alert("doing work");
//actually this function will do something and when processing is done the button is enabled by removing the 'disabled' attribute
//I use setTimeout so you can see the button can only be clicked once, and can't be clicked again while work is being done
setTimeout('$("#btn").removeAttr("disabled")', 1500);
}
working example
I modified the solution by #Kalyani and so far it's been working beautifully!
$('selector').click(function(event) {
if(!event.detail || event.detail == 1){ return true; }
else { return false; }
});
Disable pointer events in the first line of your callback, and then resume them on the last line.
element.on('click', function() {
element.css('pointer-events', 'none');
//do all of your stuff
element.css('pointer-events', 'auto');
};
After hours of searching i fixed it in this way:
old_timestamp = null;
$('#productivity_table').on('click', function(event) {
// code executed at first load
// not working if you press too many clicks, it waits 1 second
if(old_timestamp == null || old_timestamp + 1000 < event.timeStamp)
{
// write the code / slide / fade / whatever
old_timestamp = event.timeStamp;
}
});
you can use jQuery's [one][1] :
.one( events [, data ], handler ) Returns: jQuery
Description: Attach a handler to an event for the elements. The handler is executed at most once per element per event type.
see examples:
using jQuery: https://codepen.io/loicjaouen/pen/RwweLVx
// add an even listener that will run only once
$("#click_here_button").one("click", once_callback);
using count,
clickcount++;
if (clickcount == 1) {}
After coming back again clickcount set to zero.
May be this will help and give the desired functionality :
$('#disable').on('click', function(){
$('#disable').attr("disabled", true);
});
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<button id="disable">Disable Me!</button>
<p>Hello</p>
We can use on and off click for preventing Multiple clicks. i tried it to my application and it's working as expected.
$(document).ready(function () {
$("#disable").on('click', function () {
$(this).off('click');
// enter code here
});
})
This should work for you:
$(document).ready(function () {
$('.applicationButton').click(function (e) {
var btn = $(this),
isPageValid = Page_ClientValidate(); // cache state of page validation
if (!isPageValid) {
// page isn't valid, block form submission
e.preventDefault();
}
// disable the button only if the page is valid.
// when the postback returns, the button will be re-enabled by default
btn.prop('disabled', isPageValid);
return isPageValid;
});
});
Please note that you should also take steps server-side to prevent double-posts as not every visitor to your site will be polite enough to visit it with a browser (let alone a JavaScript-enabled browser).
The absolute best way I've found is to immediately disable the button when clicked:
$('#myButton').click(function() {
$('#myButton').prop('disabled', true);
});
And re-enable it when needed, for example:
validation failed
error while processing the form data by the server, then after an error response using jQuery
Another way to avoid a quick double-click is to use the native JavaScript function ondblclick, but in this case it doesn't work if the submit form works through jQuery.
One way you do this is set a counter and if number exceeds the certain number return false.
easy as this.
var mybutton_counter=0;
$("#mybutton").on('click', function(e){
if (mybutton_counter>0){return false;} //you can set the number to any
//your call
mybutton_counter++; //incremental
});
make sure, if statement is on top of your call.
If you are doing a full round-trip post-back, you can just make the button disappear. If there are validation errors, the button will be visible again upon reload of the page.
First set add a style to your button:
<h:commandButton id="SaveBtn" value="Save"
styleClass="hideOnClick"
actionListener="#{someBean.saveAction()}"/>
Then make it hide when clicked.
$(document).ready(function() {
$(".hideOnClick").click(function(e) {
$(e.toElement).hide();
});
});
Just copy paste this code in your script and edit #button1 with your button id and it will resolve your issue.
<script type="text/javascript">
$(document).ready(function(){
$("#button1").submit(function() {
$(this).submit(function() {
return false;
});
return true;
});
});
</script
Plain JavaScript:
Set an attribute to the element being interacted
Remove the attribute after a timeout
If the element has the attribute, do nothing
const throttleInput = document.querySelector('button');
throttleInput.onclick = function() {
if (!throttleInput.hasAttribute('data-prevent-double-click')) {
throttleInput.setAttribute('data-prevent-double-click', true);
throttleInput.setAttribute('disabled', true);
document.body.append("Foo!");
}
setTimeout(function() {
throttleInput.removeAttribute('disabled');
throttleInput.removeAttribute('data-prevent-double-click');
}, 3000);
}
<button>Click to add "Foo"!</button>
We also set the button to .disabled=true. I added the HTML Command input with type hidden to identify if the transaction has been added by the Computer Server to the Database.
Example HTML and PHP Commands:
<button onclick="myAddFunction(<?php echo $value['patient_id'];?>)" id="addButtonId">ADD</button>
<input type="hidden" id="hasPatientInListParam" value="<?php echo $hasPatientInListParamValue;?>">
Example Javascript Command:
function myAddFunction(patientId) {
document.getElementById("addButtonId").disabled=true;
var hasPatientInList = document.getElementById("hasPatientInListParam").value;
if (hasPatientInList) {
alert("Only one (1) patient in each List.");
return;
}
window.location.href = "webAddress/addTransaction/"+patientId; //reloads page
}
After reloading the page, the computer auto-sets the button to .disabled=false. At present, these actions prevent the multiple clicks problem in our case.
I hope these help you too.
Thank you.
One way I found that works is using bootstrap css to display a modal window with a spinner on it. This way nothing in the background can be clicked. Just need to make sure that you hide the modal window again after your long process completes.
so I found a simple solution, hope this helps.
all I had to do was create a counter = 0, and make the function that runs when clicked only runnable if the counter is = 0, when someone clicks the function the first line in the function sets counter = 1 and this will prevent the user from running the function multiple times when the function is done the last line of the code inside the function sets counter to 0 again
you could use a structure like this, it will execute just once:
document.getElementById('buttonID').addEventListener('click', () => {
...Do things...
},{once:true});

Trigger onbeforeunload if form is not submitted

I've got a form which is being submitted via PHP with 3 submit actions:
Save and Continue
Save and Exit
Exit without Saving
I'd like to trigger an "OnBeforeUnload" alert to display if the user DOES NOT click on any of the form actions to advise them that they're leaving the page, and their changes may not be saved.
I've tried the following code but it seems as though the unbeforeunload is being triggered before my click event. Any suggestions on how best to achieve this?
$buttonpressed = false;
$j(".Actions input").click(function(){
$buttonpressed = true;
});
if(!$buttonpressed){
window.onbeforeunload = function(){
return "Your changes may not be saved.";
}
}
You need to do the check inside the handler, like this:
window.onbeforeunload = function(){
if(!$buttonpressed){
return "Your changes may not be saved.";
}
}
Currently it's binding window.onbeforeunload when your code is run because $buttonpressed is false when it runs...it doesn't matter if it changes later since you already bound the handler. An alternative is to make it a bit simpler, like this:
window.onbeforeunload = function(){
return "Your changes may not be saved.";
}
$j(".Actions input").click(function(){
window.onbeforeunload = null;
});
This just removes the handler on click instead. A more appropriate event to handle other submit cases would be to attach to the submit event, like this:
$j(".myForm").submit(function(){
window.onbeforeunload = null;
});

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