Event delegation not working jquery - javascript

So I'm just getting started with event delegation and I'm still fairly confused by it but here goes:
I have a button which adds a rating in ajax, once clicked again I'd like it to remove the rating, here's the code with annotations (and some parts removed to make it look more clear).
$(document).on("click", '.add_rating', function() {
l.start();
var input = $(this).prev().children('.my_rating');
var score = input.val();
var what_do = input.attr('action_type');
var cur_average = $('.current_average').val();
var data = {};
data.score = score;
data.media_id = <?php echo $title_data->media_id; ?>;
data.what_do = what_do;
$.ajax({
dataType: "json",
type: 'post',
url: 'jquery/actions/add_remove_rating',
data: data,
success: function(data) {
if (data.comm === 'success') {
//do some other stuff there, irrelevant
$('.ladda-button').removeClass('btn-primary');
$('.ladda-button').removeClass('btn-sm');
$('.ladda-button').addClass('btn-danger btn-xs');
$('.ladda-label').html('Remove');
$('.ladda-button').addClass('remove_rating'); <-- add the remove rating class I want to call if the button is clicked again
input.attr('action_type', 'remove_rating');
l.stop();
}
}
});
$('.remove_rating').on('click', function() { <-- this doesn't work, why?
alert('remove was clicked');
});
});
I can't seem to trigger this:
$('.remove_rating').on('click', function() { <-- this doesn't work, why?
alert('remove was clicked');
});
Any help appreciated!
Edit: on a side note, I don't actually need this to work as php figures out if we're removing or adding a score based on the action_type attribute. I just wanted to find out why it's not triggering.

change your code to:
$(document).on("click", '.add_rating', function() {
l.start();
var input = $(this).prev().children('.my_rating');
var score = input.val();
var what_do = input.attr('action_type');
var cur_average = $('.current_average').val();
var data = {};
data.score = score;
data.media_id = <?php echo $title_data->media_id; ?>;
data.what_do = what_do;
$.ajax({
dataType: "json",
type: 'post',
url: 'jquery/actions/add_remove_rating',
data: data,
success: function(data) {
if (data.comm === 'success') {
//do some other stuff there, irrelevant
$('.ladda-button').removeClass('btn-primary');
$('.ladda-button').removeClass('btn-sm');
$('.ladda-button').addClass('btn-danger btn-xs');
$('.ladda-label').html('Remove');
$('.ladda-button').addClass('remove_rating'); <-- add the remove rating class I want to call if the button is clicked again
input.attr('action_type', 'remove_rating');
l.stop();
$('.remove_rating').on('click', function() { <-- this doesn't work, why?
alert('remove was clicked');
});
}
}
});
});
EXPLANATION:
first have a look here: Understanding Event Delegation.
event delegation is used when you need to create event handlers for elements that do not exist yet. you add a .remove_rating class to elements dynamically, however you are trying to attach a handler to elements with the above mentioned class before you even attach it.
you are attaching the class when the asynchronous ajax call returns, in the success function, however your event handler block is being processed right after you send the ajax, and not after the ajax returns (ajax is async rememeber?). therefore, you need to wait until the ajax returns and the elements are created, and only then attach the handler to them.
alternatively, using event delegation, you can attach the handler to the document, like you did in the following line:
$(document).on("click", '.add_rating', function() {
it means, that you attach the handler to the document, and whenever any element ON the document is clicked, if that element has the class '.add_rating' then execute the handler.
therefore, you may attach another handler to the document to monitor for clicks on elements with the .remove_rating class as follows:
$(document).on("click", '.remove_rating', function() {
this is called event delegation, because you delegate the event to a parent element.

Because class was added after click event initialised. You need to use live event handlers, like this:
$( document ).on('click', '.remove_rating', function() {
In this case .remove_rating click handler will work on dynamically created elements and on class name changes.

Related

Ajax form is sent twice if validation errors take place

I know about event.preventDefault() and event.stopImmediatePropagation(). But it doesn't work for me. In my case I have such ajax call:
$('#templateConfirmDialog').on('show.bs.modal', function (event) {
$(this).find('.modal-yes').click(function(){
var form = form2js('search_form', '.', true, function (node) {}, false);
var requestData = JSON.stringify(form, replacer);
var $formErrors = $('.search_form').find('.alert-danger');
event.preventDefault();
event.stopImmediatePropagation();
$.ajax({
type: 'POST',
contentType : "application/json",
url: '/fraud/template/testCreate',
data: requestData,
dataType: 'json',
success: function (data) {
$formErrors.text('');
//if no errors just reload
if (data === undefined || data.length === 0) {
location.reload();
}
else {
//else bind error messages
data.forEach(function(error) {
$('#new-' + error.field + '-error').text(error.defaultMessage);
})
}
}
});
});
My problem is that the ajax call is prevented as much times as I made attempts to input data. If I entered invalid data once - ajax is called twice. If twice - 3 times. What may be a reason of such behavior?
Every time this event happens:
$('#templateConfirmDialog').on('show.bs.modal', function (event) {
You bind a new click event handler:
$(this).find('.modal-yes').click(function(){
So if you show.bs.modal twice, then you have two click event handlers both submitting the AJAX request. Instead, just bind the click event handler once to the target clickable element, instead of binding it every time the modal is displayed.
Replace this:
$('#templateConfirmDialog').on('show.bs.modal', function (event) {
$(this).find('.modal-yes').click(function(){
//...
});
});
With this:
$('#templateConfirmDialog').find('.modal-yes').click(function(){
//...
});
Or, if that element is dynamically added to the DOM, this:
$(document).on('click', '#templateConfirmDialog .modal-yes', function(){
//...
});
That way there's just a single click event handler created when the page loads, rather than adding a new handler every time you display the modal.

jQuery function doesn't work after after loading dynamic content

I'm using below code. This is bootstrap 3 delete conformation message.
$(document).ready(function(){
$('a.btnDelete').on('click', function (e) {
e.preventDefault();
var id = $(this).closest('div').data('id');
$('#myModal').data('id', id).modal('show');
});
$('#btnDelteYes').click(function () {
var id = $('#myModal').data('id');
var dataString = 'id='+ id ;
$('[data-id=' + id + ']').parent().remove();
$('#myModal').modal('hide');
//ajax
$.ajax({
type: "POST",
url: "delete.php",
data: dataString,
cache: false,
success: function(html)
{
//$(".fav-count").html(html);
$("#output").html(html);
}
});
//ajax ends
});
});
This is the trigger element that I'm using
<div data-id="MYID"><a class="btnDelete" href="#">Delete</a></div>
And I'm using the same HTML element dynamically to trigger delete and it doesn't work.
Can someone point me the correct way to do it?
You have to use event delegation
$(document).on("click" , '#btnDelteYes' ,function () {
Pretty much: bind the click higher up to something that exists when the script is run, and when that something is clicked, tell it to pass the click event to the #btnDelteYes element instead
I cant understand what exactly you are doing on your code due to missing information, but the answer is: you should use event delegation on the dynamically inserted content
you can try
$('[data-id=MYID]').on('click','.btnDelteYes',function({
e.preventDefault();
var id = $(this).closest('div').data('id');
$('#myModal').data('id', id).modal('show');
});
here <div data-id="MYID"> should be a hard coded html content and The idea is to delegate the events to that wrapper, instead of binding handlers directly on the dynamic elements.

Query function not being fired when called

I have a Jquery function to delete a row in an HTML table, it looks like this;
$(document).ready(function(){
$("#thisNet td a.delete").click(function() {
if (confirm("Are you sure you want to delete this row?")) {
var id = $(this).parent().parent().attr('id');
var data = 'id=' + id ;
var parent = $(this).parent().parent();
$.ajax({
type: "POST",
url: "delete-row.php",
data: data,
cache: false,
success: function()
{
parent.fadeOut('slow', function() {$(this).remove();});
}
});
}
});
});
I don't know if it works or not because when I click the button I never get into the function. The delete item to click is in a table created by PHP/MySQL. I followed the tutorial here; https://sarfraznawaz.wordpress.com/2009/09/14/deleting-table-rows-using-jquery-and-php/ to create the delete function. I'm guessing the reason it doesn't fire has to do with timing. The $(document).ready(function() already thinks the page is done loading before the table is created..but I don't know how to overcome this problem.
The page is here; http://kcmecc.org/RaspPi/ once you access it use the drop down to select Net #1. The delete column is the last one with the red x.
Your delete button doesn't exist on document ready. You need to use .on to delegate the event to an ancestor element when dynamically adding elements...
$(document).on('click', '#thisNet td a.delete', function() {

Jquery doesnot bind events to ajax added dom

I have an ajax function that loads the content of 4 checkboxes as follows:
$.ajax({
url : some url..,
dataType : 'json',
success : function(data) {
buildCheckboxes(data);
},
error : function(data) {
do something...
}
});
build checkboxes methods does something like this:
function updateNotificationMethods(items) {
var html = [];
$.each(items, function(i, item) {
htmlBuilder = [];
htmlBuilder.push("<input type='checkbox' class='checkbox-class' name='somename' value='");
htmlBuilder.push(item.id);
htmlBuilder.push("'");
htmlBuilder.push("/> ");
htmlBuilder.push(item.name);
htmlBuilder.push("<br/><br/>")
html.push(htmlBuilder.join(''));
});
$("#div").html(html.join(''));
}
i have also an event binder that should be triggered when checkbox value changes:
$(".checkbox-class").change(function() {
alert("change");
});
it works if i have the checkboxes html in the source (i.e. static) as opposed to the set up i have here, where i dynamically load the data from server.
is there something i can do so that binding take place timely?
peace!
This is because the element is not present when you bind your handler.
Try this:
$( document ).on( 'change', '.checkbox-class', function() {
alert("change");
});
Or if you are using an older version of jQuery (less than 1.7) ...
$( '.checkbox-class' ).live( function() {
alert("change");
});
Checkboxes are not available while you are binding the events. jsfiddle
Assuming that element with id div is present while binding the event.
$("#div").on("change",".checkbox-class",function() {
alert("change");
});
This code:
$(".checkbox-class").change(function() {
alert("change");
});
do not establishes a continuous and on-going rule, instead, this code attaches an event manager (in this case to the change event) to each matching DOM object that exists at the moment it is executed.
If you want you can re-execute this code (or one similar and narrow) each time you add checkboxes to the DOM.

jquery click event

I have some jquery that looks like this,
$('.career_select .selectitems').click(function(){
var selectedCareer = $(this).attr('title');
$.ajax({
type: 'POST',
url: '/roadmap/step_two',
data: 'career_choice='+selectedCareer+"&ajax=true&submit_career=Next",
success: function(html){
$('.hfeed').append(html);
$('#grade_choice').SelectCustomizer();
}
});
});
My problem is that if the user keeps clicking then the .hfeed keeps getting data appended to it. How can I limit it so that it can only be clicked once?
Use the one function:
Attach a handler to an event for the elements. The handler is executed at most once per element
If you wanted the element to only be clicked once and then be re-enabled once the request finishes, you could:
A) Keep a state variable that updates if a request is currently in progress and exits at the top of the event if it is.
B) Use one, put your code inside a function, and rebind upon completion of request.
The second option would look like this:
function myClickEvent() {
var selectedCareer = $(this).attr('title');
var that = this;
$.ajax({
type: 'POST',
url: '/roadmap/step_two',
data: 'career_choice='+selectedCareer+"&ajax=true&submit_career=Next",
success: function(html){
$('.hfeed').append(html);
$('#grade_choice').SelectCustomizer();
},
complete: function() {
$(that).one('click', myClickEvent);
}
});
}
$('.career_select .selectitems').one('click', myClickEvent);
You can either use a global variable like
var added = false;
$('.career_select .selectitems').click(function(){
if(!added) {
// previous code here
added = true;
}
});
or use .one("click", function () { ... }) instead of the previous click function to execute the handler at most once per element. See http://api.jquery.com/one/ for more details.

Categories

Resources