prevent jQuery post request executed twice by double click - javascript

I've searched for equal questions, but found not a single one for my specific case.
I have an element
<span id="myButton">Click</span>
and a jQuery post-request bound to it
$(document).ready( function()
{
$(document).on( 'click', '#myButton', function(e)
{
$.post( "RESPONDING_WEBPAGE_HERE.php" ).done( function( result )
{
console.log( result );
});
});
});
Now, for every time you click the button, it makes a post-request. Makes sense. What I want is a good solution for only executing the post-request, if the result function (.done()) is executed.
For sure, I know to handle that with a variable like var isAjaxRequest = false; setting it to true, and back to false in the resulting function, but maybe there is a better (jQuery build-in) way of doing it.
Here is my solution by now. I would be really great if there are better ones.
var isAjaxRequest = false;
$(document).ready( function()
{
$(document).on( 'click', '#myButton', function(e)
{
if( !isAjaxRequest )
{
isAjaxRequest = true;
$.post( "RESPONDING_WEBPAGE_HERE.php" ).done( function( result )
{
isAjaxRequest = false;
console.log( result );
});
}
});
});
Thank you =)

I commonly set the button to disabled when it is clicked and then remove the disabled attribute on the callbacks for the POST request.
$(document).on('click', '#button', function () {
$('#button').attr('disabled', true);
$.post('something').done(function () {
$('#button').removeAttr('disabled');
}).fail(function () {
$('#button').removeAttr('disabled');
});
});
This will prevent the button from being clicked again once it has already been clicked.
As per the comments; If you want this behaviour on a span element or others which don't allow the disabled attribute, you could set a class when clicked.
$(document).on('click', 'span#button:not(.disabled)', function () {
$(this).addClass('disabled');
$.post('something').done(function () {
$(this).removeClass('disabled');
}).fail(function () {
$(this).removeClass('disabled');
});
});
The above code will make sure the element can only be clicked if it doesn't have the disabled class. This will also work for the button elements so there is no need to duplicate code for both methods.

I like to use .one() to attach the event handler and re-attach the event after the ajax call is complete. This will handle all cases even when your target doesn't support disabling:
//define handler function
var myButtonHandler = function(e) {
$.post("RESPONDING_WEBPAGE_HERE.php").done(function() {
attachButtonHandler("#mybutton"); //re-attach the click event after AJAX complete
});
}
//attach an event handler that's only good for one click
function attachButtonHandler(selector) {
$(document).one('click', selector, myButtonHandler);
}
//on doc ready, attach the event handler for the first time
$(function() {
attachButtonHandler("#mybutton");
});

Related

JS - use preventDefault instead of return false

Not great with Js so looking for some help with some existing code.
I have the following anchor
<span>Add</span>
I am getting a warning regarding the 'onclick' event where its telling me that i dont have keyboard equivilant handler for the the onclick="return false; I have done some research and i can prevent this warning by using preventDefault. if i put this in a script tag in the page then it works the same and i think it will get rid of the issue.
$("a.addrom").click(function(e) {
e.preventDefault();
});
However, i would prefer to add it to the existing js but im having a hard time working out whats going on. I am trying to add it to the click event.
setupRooms: function (settings) {
//hide all age fields
$(settings.agesSelector, settings.hotelSearchDiv).hide();
//hide all except first
$(settings.roomsSelector + ":not(:first)", settings.hotelSearchDiv).hide();
$('select', settings.hotelSearchDiv).prop('selectedIndex', 0); //set all to 0
$(settings.addRoomSelector, settings.hotelSearchDiv).on('click', function () {
methods.addRoom(settings);
});
$(settings.removeRoomSelector, settings.hotelSearchDiv).on('click', function () {
var id = $(this).data('id');
methods.removeLastRoom(settings, id);
});
$(settings.childrenNumberSelector, settings.hotelSearchDiv).on('change', function () {
methods.handleChildrenChange(settings, $(this));
});
},
Edit* This code worked for me thanks to #patrick & #roberto
$(settings.addRoomSelector, settings.hotelSearchDiv).on('click', function (e) {
e.preventDefault();
methods.addRoom(settings);
});
If i understood correctly you want to add that on your click handlers:
$(settings.addRoomSelector, settings.hotelSearchDiv).on('click', function (e) {
e.preventDefault();
methods.addRoom(settings);
});
$(settings.removeRoomSelector, settings.hotelSearchDiv).on('click', function (e) {
e.preventDefault();
var id = $(this).data('id');
methods.removeLastRoom(settings, id);
});
Should be enough for having the prevent default in your click handlers.
Cheers

Disabling and enabling click event on image...jquery

what would be the best way to enable and then re-enable and image click with jquery?
I can diasble the click event easy enough
$(document).on("click", "#rightPager", function () {
if (condition) {
$(this).click(false);
}
});
how would I go about in 'enabling' the click event again based on a certain condition?.
I would want to enable the button again for example
$(document).on("click", "#leftPager", function () {
$("#rightPager").click(true);
});
In order to rebind you would need to use the original .on("click") event again.
Write a function to bind an event to your image:
function bindImage() {
$(img).on("click", function() {
// Your bind event goes here
});
}
Then write a conditional to unbind the event on the image if your condition returns true, then if its false, rebind the event to the image as normal.
if (condition) {
$(img).unbind();
} else {
bindImage();
}
Alternatively, you could complete this within a single function such as:
$(document).on("click", "#rightPager", function () {
if (condition) {
// terminate the function
return false;
} else {
// put your function here to run as normal
}
});
Try to use jQuery off method.
JSFiddle
$(document).off('click', '#rightPager');
Full code:
var condition = true;
$(document).on("click", "#rightPager", function () {
if(condition){
alert('Click was disabled');
$(document).off('click', '#rightPager');
}
});
you disable the default event by:
$(document).click(function(e) {
e.preventDefault();
condition ? doSomething() : doSomethingElse();
});​
so basically is not that you enable then disable, you prevent the default action, check for your condition and they execute appropriate function

Intercept clicks, make some calls then resume what the click should have done before

Good day all, I have this task to do:
there are many, many many webpages, with any kind of element inside, should be inputs, buttons, links, checkboxes and so on, some time there should be a javascript that could handle the element behaviour, sometimes it is a simple ... link.
i have made a little javascript that intercepts all the clicks on clickable elements:
$( document ).ready(function() {
$('input[type=button], input[type=submit], input[type=checkbox], button, a').bind('click', function(evt, check) {
if (typeof check == 'undefined'){
evt.preventDefault();
console.log("id:"+ evt.target.id+", class:"+evt.target.class+", name:"+evt.target.name);
console.log (check);
$(evt.target).trigger('click', 'check');
}
});
});
the logic is: when something is cllicked, I intercept it, preventDefault it, make my track calls and then resme the click by trigger an event with an additional parameter that will not trigger the track call again.
but this is not working so good. submit clicks seams to work, but for example clicking on a checkbox will check it, but then it cannot be unchecked, links are simply ignored, I track them (in console.log() ) but then the page stay there, nothing happens.
maybe I have guessed it in the wrong way... maybe i should make my track calls and then bind a return true with something like (//...track call...//).done(return true); or something...
anyone has some suggestions?
If you really wanted to wait with the click event until you finished with your tracking call, you could probably do something like this. Here's an example for a link, but should be the same for other elements. The click event in this example fires after 2seconds, but in your case link.click() would be in the done() method of the ajax object.
google
var handled = {};
$("#myl").on('click', function(e) {
var link = $(this)[0];
if(!handled[link['id']]) {
handled[link['id']] = true;
e.preventDefault();
e.stopPropagation();
//simulate async ajax call
window.setTimeout(function() {link.click();}, 2000);
} else {
//reset
handled[link['id']] = false;
}
});
EDIT
So, for your example, this would look something like this
var handled = {};
$( document ).ready(function() {
$('input[type=button], input[type=submit], input[type=checkbox], button, a').bind('click', function(evt) {
if(!handled[evt.target.id]) {
handled[evt.target.id] = true;
evt.preventDefault();
evt.stopPropagation();
$.ajax({
url: 'your URL',
data: {"id" : evt.target.id, "class": evt.target.class, "name": evt.target.name},
done: function() {
evt.target.click();
}
});
} else {
handled[evt.target.id] = false;
}
});

jquery how to combine two selectors to second function of single toggle event

If I have a regular toggle function bound to a click event
$('#work-content a').toggle(
function() {
// first click stuff
}, function() {
// second click stuff
}
);
But, I also need to bind $(document).click event to the second function somehow. My logic is probably off so I'm sure a new solution is necessary.
Functionality is 1) do something when link is clicked then 2) do the opposite when the link is clicked again or if the outside of the #work-content div is clicked.
Just extract the anonymous function and give it a name:
var thatFunction = function () {
...
}
$('#work-content a').toggle(
function() {
// first click stuff
},
thatFunction);
$(document).click(thatFunction);
the toggle function is used to hide/show your div and should not be used to maintain state of an event. just use another local variable for this and also define two functions perform your two different actions and pass the function pointer as callback to your event listener.
thus:
var linkClicked=false;
function fun1(){}
function fun2(){}
$('#work-content a').click(
function() {
if(!linkClicked)
fun1();
else
fun2();
});
$("body").click(function(){
if($(event.target).closest("#work-content")===null) //to make sure clicking inside your div does not trigger its close
{
fun2();
}
});
linkClicked = false;
$('#work-content .pic a').click(function(event) {
event.preventDefault();
var c = $(this);
if (!linkClicked) {
values = workOpen($(this));
} else {
workClose(c, values);
}
$('body').one('click',function() {
workClose(c, values);
});
});
This solution was exactly what I needed for what it's worth.

What is the opposite of evt.preventDefault();

Once I've fired an evt.preventDefault(), how can I resume default actions again?
As per commented by #Prescott, the opposite of:
evt.preventDefault();
Could be:
Essentially equating to 'do default', since we're no longer preventing it.
Otherwise I'm inclined to point you to the answers provided by another comments and answers:
How to unbind a listener that is calling event.preventDefault() (using jQuery)?
How to reenable event.preventDefault?
Note that the second one has been accepted with an example solution, given by redsquare (posted here for a direct solution in case this isn't closed as duplicate):
$('form').submit( function(ev) {
ev.preventDefault();
//later you decide you want to submit
$(this).unbind('submit').submit()
});
function(evt) {evt.preventDefault();}
and its opposite
function(evt) {return true;}
cheers!
To process a command before continue a link from a click event in jQuery:
Eg: Click me
Prevent and follow through with jQuery:
$('a.myevent').click(function(event) {
event.preventDefault();
// Do my commands
if( myEventThingFirst() )
{
// then redirect to original location
window.location = this.href;
}
else
{
alert("Couldn't do my thing first");
}
});
Or simply run window.location = this.href; after the preventDefault();
OK ! it works for the click event :
$("#submit").click(function(event){
event.preventDefault();
// -> block the click of the sumbit ... do what you want
// the html click submit work now !
$("#submit").unbind('click').click();
});
event.preventDefault(); //or event.returnValue = false;
and its opposite(standard) :
event.returnValue = true;
source:
https://developer.mozilla.org/en-US/docs/Web/API/Event/returnValue
I had to delay a form submission in jQuery in order to execute an asynchronous call. Here's the simplified code...
$("$theform").submit(function(e) {
e.preventDefault();
var $this = $(this);
$.ajax('/path/to/script.php',
{
type: "POST",
data: { value: $("#input_control").val() }
}).done(function(response) {
$this.unbind('submit').submit();
});
});
I would suggest the following pattern:
document.getElementById("foo").onsubmit = function(e) {
if (document.getElementById("test").value == "test") {
return true;
} else {
e.preventDefault();
}
}
<form id="foo">
<input id="test"/>
<input type="submit"/>
</form>
...unless I'm missing something.
http://jsfiddle.net/DdvcX/
This is what I used to set it:
$("body").on('touchmove', function(e){
e.preventDefault();
});
And to undo it:
$("body").unbind("touchmove");
There is no opposite method of event.preventDefault() to understand why you first have to look into what event.preventDefault() does when you call it.
Underneath the hood, the functionality for preventDefault is essentially calling a return false which halts any further execution. If you’re familiar with the old ways of Javascript, it was once in fashion to use return false for canceling events on things like form submits and buttons using return true (before jQuery was even around).
As you probably might have already worked out based on the simple explanation above: the opposite of event.preventDefault() is nothing. You just don’t prevent the event, by default the browser will allow the event if you are not preventing it.
See below for an explanation:
;(function($, window, document, undefined)) {
$(function() {
// By default deny the submit
var allowSubmit = false;
$("#someform").on("submit", function(event) {
if (!allowSubmit) {
event.preventDefault();
// Your code logic in here (maybe form validation or something)
// Then you set allowSubmit to true so this code is bypassed
allowSubmit = true;
}
});
});
})(jQuery, window, document);
In the code above you will notice we are checking if allowSubmit is false. This means we will prevent our form from submitting using event.preventDefault and then we will do some validation logic and if we are happy, set allowSubmit to true.
This is really the only effective method of doing the opposite of event.preventDefault() – you can also try removing events as well which essentially would achieve the same thing.
Here's something useful...
First of all we'll click on the link , run some code, and than we'll perform default action. This will be possible using event.currentTarget Take a look. Here we'll gonna try to access Google on a new tab, but before we need to run some code.
Google
<script type="text/javascript">
$(document).ready(function() {
$("#link").click(function(e) {
// Prevent default action
e.preventDefault();
// Here you'll put your code, what you want to execute before default action
alert(123);
// Prevent infinite loop
$(this).unbind('click');
// Execute default action
e.currentTarget.click();
});
});
</script>
None of the solutions helped me here and I did this to solve my situation.
<a onclick="return clickEvent(event);" href="/contact-us">
And the function clickEvent(),
function clickEvent(event) {
event.preventDefault();
// do your thing here
// remove the onclick event trigger and continue with the event
event.target.parentElement.onclick = null;
event.target.parentElement.click();
}
I supose the "opposite" would be to simulate an event. You could use .createEvent()
Following Mozilla's example:
function simulateClick() {
var evt = document.createEvent("MouseEvents");
evt.initMouseEvent("click", true, true, window,
0, 0, 0, 0, 0, false, false, false, false, 0, null);
var cb = document.getElementById("checkbox");
var cancelled = !cb.dispatchEvent(evt);
if(cancelled) {
// A handler called preventDefault
alert("cancelled");
} else {
// None of the handlers called preventDefault
alert("not cancelled");
}
}
Ref: document.createEvent
jQuery has .trigger() so you can trigger events on elements -- sometimes useful.
$('#foo').bind('click', function() {
alert($(this).text());
});
$('#foo').trigger('click');
This is not a direct answer for the question but it may help someone. My point is you only call preventDefault() based on some conditions as there is no point of having an event if you call preventDefault() for all the cases. So having if conditions and calling preventDefault() only when the condition/s satisfied will work the function in usual way for the other cases.
$('.btnEdit').click(function(e) {
var status = $(this).closest('tr').find('td').eq(3).html().trim();
var tripId = $(this).attr('tripId');
if (status == 'Completed') {
e.preventDefault();
alert("You can't edit completed reservations");
} else if (tripId != '') {
e.preventDefault();
alert("You can't edit a reservation which is already attached to a trip");
}
//else it will continue as usual
});
jquery on() could be another solution to this. escpacially when it comes to the use of namespaces.
jquery on() is just the current way of binding events ( instead of bind() ). off() is to unbind these. and when you use a namespace, you can add and remove multiple different events.
$( selector ).on("submit.my-namespace", function( event ) {
//prevent the event
event.preventDefault();
//cache the selector
var $this = $(this);
if ( my_condition_is_true ) {
//when 'my_condition_is_true' is met, the binding is removed and the event is triggered again.
$this.off("submit.my-namespace").trigger("submit");
}
});
now with the use of namespace, you could add multiple of these events and are able to remove those, depending on your needs.. while submit might not be the best example, this might come in handy on a click or keypress or whatever..
you can use this after "preventDefault" method
//Here evt.target return default event (eg : defult url etc)
var defaultEvent=evt.target;
//Here we save default event ..
if("true")
{
//activate default event..
location.href(defaultEvent);
}
You can always use this attached to some click event in your script:
location.href = this.href;
example of usage is:
jQuery('a').click(function(e) {
location.href = this.href;
});
In a Synchronous flow, you call e.preventDefault() only when you need to:
a_link.addEventListener('click', (e) => {
if( conditionFailed ) {
e.preventDefault();
// return;
}
// continue with default behaviour i.e redirect to href
});
In an Asynchronous flow, you have many ways but one that is quite common is using window.location:
a_link.addEventListener('click', (e) => {
e.preventDefault(); // prevent default any way
const self = this;
call_returning_promise()
.then(res => {
if(res) {
window.location.replace( self.href );
}
});
});
You can for sure make the above flow synchronous by using async-await
this code worked for me to re-instantiate the event after i had used :
event.preventDefault(); to disable the event.
event.preventDefault = false;
I have used the following code. It works fine for me.
$('a').bind('click', function(e) {
e.stopPropagation();
});

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