How to catch elements onclick event when element may be created in future or added dynamically?
// Here i need to define function for click
// In jQuery it would be like this: jQuery('body').on('click', 'a.some-link-class', function(){});
var some_link = document.createElement('a');
some_link.class = 'some-link-class';
some_link.href = '#';
var some_link_text = document.createTextNode('Some Link Title');
some_link.appendChild(some_link_text);
document.body.appendChild(some_link);
You can attach an event to the body and test if the source of the event is the control type you want, or a class, or something else.
//attach the event to everything in the body
document.body.addEventListener('click', eventFunction, false);
//event function
function eventFunction(e)
{
//test if the source triggering the event is an element from the class you want
//you can do the test on the class, tagname... anything you desire
if(e.ClassName.match('myclass'))
{
//do something if the class matches
dosomething();
}
}
With this, you can create any element you want after that. If they have the good class they will trigger the event if clicked and the function will run.
You must use event delegation for JS. just attach an event to a parent item or document and check in the parent if trigger is your element. You can use a class name or tag name etc.
// Get the element, add a click listener...
document.getElementById("parent-list").addEventListener("click",function(e) {
// e.target is the clicked element!
// If it was a list item
if(e.target && e.target.nodeName == "LI") {
// List item found! Output the ID!
console.log("List item ",e.target.id.replace("post-")," was clicked!");
}
});
in this way the event also works for elements what will be added afterwards.
Just attach it when you create it:
some_link.onclick = function() {
//do stuff
}
Either
some_link.addEventListener('click', handler);
or
some_link.onclick = handler;
Related
I have an anchor tag (namely Cancel button) with a class attribute and href attribute in a jsp file .
I have written an onclick event for the class attribute in a seperate js file. So when the button is clicked, the onclick event executes and then takes to the href link.
When the button is clicked more than once it takes me to an empty page or an error page.
I want to prevent more than one click on the button.
I have tried using event.preventdefault() function inside my onclick() function but the href link is not working if I do that.
Any other way?
My JS code:
$('.cancel-btn').on('click',function(evt){
//evt.preventDefault();
//My Code
});
jQuery one() method will perform click event only once:
$('.cancel-btn').one('click',function(evt){
// evt.preventDefault();
// code here
});
Also possible using jQuery on() method that may be more useful when the event should be removed conditionally:
let count = 0; // or may be a boolean flag
$('.cancel-btn').on('click', function(evt){
if (count == 0) {
count++;
// code here
} else {
return false;
// or evt.preventDefault();
}
});
Or like this:
$('.cancel-btn').on('click', function(evt) {
// code here
// then remove the event handler.
$(this).off('click');
});
Try using a boolean flag to make sure the function executes only once
var executeOnce = false;
$('.cancel-btn').on('click',function(evt){
if(!executeOnce){
//evt.preventDefault();
//My Code
executeOnce = true;
}
});
Here you go with one more way to do it using pointer-events as none
https://jsfiddle.net/w2wnuyv6/1/
$('a[value="cancel"]').click(function(){
$(this).css({
'pointer-events': 'none'
});
});
you can write a function like this:
function clickOnce (element ,listener){
element.addEventListener("click", function (event){
listener(event);
element.removeEventListener("click", arguments.callee);
});
}
jsfiddle
As you mentioned the event is written on that class, you can use this simple code to ensure that its clicked only once:
$('.cancel-btn').on('click', function(evt) {
// execue your code
$(this).removeClass('cancel-btn');
});
This code will remove the class from the DOM and hence the click event will never get fired.
Optionally, You can use off() to remove an event like so:
$(".cancel-button").off("click");
This will remove all click events bound to this element. In your code, it would be like:
$('.cancel-btn').on('click', function(evt) {
// execue your code
$(this).off("click");
});
I'm using the on event listener to listen for dynamically added select elements. When an event happens is there a way to get the specific select element? this references ul.form.
$('ul.form').on('change', $("select[id$='end']"), function () {
var selector = // unsure what goes here.
self.modify(this);
});
$('ul.form').on('change', $("select[id$='end']"), function (e) {
var selector = e.target;
self.modify(this);
});
I'm working in a card game system that the player can select the card by clicking on it and then select the place to put it on. My problem is that when the player click on the target place, nothing happens.
This is my try: http://jsfiddle.net/5qMHz/
And this is my code:
function target() {
$(".target").on("click", function() {
$("#"+x).appendTo(this);
console.log(x);
});
};
What's wrong?
Try binding with document, since you change the class during document ready and there was no element with the class target initially
$(document).on("click",".target", function() {
$("#" + x).appendTo(this);
console.log(x);
}
WORKING FIDDLE
Firstly, your practice of putting function references in to jQuery objects is rather odd. The problem however is that because the .target class is applied after DOM load you need to use a delegate selector. Try this:
var $card
$(".card").on("click", function () {
$card = $(this);
if ($(".myslot").length) {
if ($(".myslot").is(':empty')) {
$(".myslot:empty").addClass("target");
} else {
alert('No empty slots');
}
}
});
$('.field').on('click', ".target", function () {
$card.appendTo(this);
$card = $();
});
Example fiddle
At the moment you are trying to bind the event handler, the elements don't have a class target yet. From the documentation:
Event handlers are bound only to the currently selected elements; they must exist on the page at the time your code makes the call to .on().
(Technically the elements exist, but they are not (yet) addressable by the class target)
You have three options to solve this:
Add the class to your HTML markup.
Bind the handler after you added the class to the elements.
Use event delegation.
The first two don't really fit to your use case, since your are adding the class target in response to an other event and the number of elements with the class target changes over time. This is a good use case for event delegation though:
$('.field').on('click', '.target', function() {
// ...
});
<body>
<div id="aaa">
<div id="bbb">
</div>
</div>
</body>
$(#?????).click(function(){
$('#bbb').hide();
})
http://jsfiddle.net/GkRY2/
What i must use if i want hide #bbb if user click outside box #bbb? But if i click on div #bbb then box is still visible - only outside.
$('body').click(function(e){
if( e.target.id == 'bbb' )
{ return true; }
else
{ $('#bbb').hide(); }
});
A note of explanation: There are a few ways to do this, either way we need to listen for a click on a parent element, weather it be a direct parent like #aaa or a distant parent like the body or the document. This way we can capture clicks that occur outside of #bbb.
Now that we have that we need the .hide to NOT occur if the user did click inside of #bbb. We can do this two ways
Stop propagation if the user clicks on #bbb. This will make the click event not 'bubble' up to the parent. That way the click event never reaches the parent and so #bbb will not hide. I personally don't like this method because stop propagation will so ALL click events from bubbling, and you may have click events that you would like to bubble to a local parent and not a distant parent. Or you may have listeners delegated from a distant parent, which will stop working if click propagation is stopped.
Check for the #bbb element in the parent listener. This is the method shown above. Basically this listens on a distant parent, and when a click occurs it checks to see if that click is on #bbb specifically. If it IS NOT on #bbb .hide is fired, otherwise it returns true, so other things that may be tied into the click event will continue working. I prefer this method for that reason alone, but secondarily its a-little bit more readable and understandable.
Finally the manner in which you check to see if the click originated at #bbb you have many options. Any will work, the pattern is the real meat of this thing.
http://jsfiddle.net/tpBq4/ //Modded from #Raminson who's answer is very similar.
New suggestion, leverage event bubbling without jQuery.
var isOutSide = true
bbb = documment.getElementById('bbb');
document.body.addEventListener('click', function(){
if(!isOutSide){
bbb.style.display = 'none';
}
isOutSide = true;
});
bbb.addEventListener('click', function(){
isOutSide = false;
});
Catch the click event as it bubbles-up to the document element. When it hits the document element, hide the element. Then in a click event handler for the element, stop the propagation of the event so it doesn't reach the document element:
$(function () {
$(document).on('click', function () {
$('#bbb').hide();
});
$('#bbb').on('click', function (event) {
event.stopPropagation();
});
});
Here is a demo: http://jsfiddle.net/KVXNL/
Docs for event.stopPropagation(): http://api.jquery.com/event.stopPropagation/
I made a plugin that does this. It preserves the value for this where as these other solutions' this value will refer to document.
https://github.com/tylercrompton/clickOut
Use:
$('#bbb').clickOut(function () {
$(this).hide();
});
You can use target property of the event object, try the following:
$(document).click(function(e) {
if (e.target.id != 'bbb') {
$('#bbb').hide();
}
})
DEMO
This will work
$("#aaa").click(function(){
$('#bbb').hide();
});
$("#bbb").click(function(event){
event.stopPropagation();
})
Becouse bbb is inside the aaa the event will "bubbel up to aaa". So you have to stop the bubbling by using the event.stopPropagation when bbb is clicked
http://jsfiddle.net/GkRY2/5/
OK
* this is none jquery. you can easly modify it to work with IE
first create helper method to facilitate codding don't get confused with JQuery $()
function $g(element) {
return document.getElementById(element);
}
create our listener class
function globalClickEventListener(obj){
this.fire = function(event){
obj.onOutSideClick(event);
}
}
let's say we need to capture every click on document body
so we need to create listeners array and initialize our work. This method will be called on load
function initialize(){
// $g('body') will return reference to our document body. parameter 'body' is the id of our document body
$g('body').globalClickEventListeners = new Array();
$g('body').addGlobalClickEventListener = function (listener)
{
$g('body').globalClickEventListeners.push(listener);
}
// capture onclick event on document body and inform all listeners
$g('body').onclick = function(event) {
for(var i =0;i < $g('body').globalClickEventListeners.length; i++){
$g('body').globalClickEventListeners[i].fire(event);
}
}
}
after initialization we create event listener and pass reference of the object that needs to know every clcik on our document
function goListening(){
var icanSeeEveryClick = $g('myid');
var lsnr = new globalClickEventListener(icanSeeEveryClick);
// add our listener to listeners array
$g('body').addGlobalClickEventListener(lsnr);
// add event handling method to div
icanSeeEveryClick.onOutSideClick = function (event){
alert('Element with id : ' + event.target.id + ' has been clicked');
}
}
* Take into account the document body height and width
* Remove event listeners when you don't need them
$(document).click(function(event) {
if(!$(event.target).closest('#elementId').length) {
if($('#elementId').is(":visible")) {
$('#elementId').hide('fast');
}
}
})
Change the "#elementId" with your div.
I have a div
<div class="myDiv">
somelink
<div class="anotherDiv">somediv</div>
</div>
Now, using event delegation and the concept of bubbling I would like to intercept clicks from any of myDiv, myLink and anotherDiv.
According to best practices this could be done by listening for clicks globally (hence the term 'delegation') on the document itself
$(document).click(function(e) {
var $eventElem = $(e.target);
var bStopDefaultClickAction = false;
if ($eventElem.is('.myDiv'))
{
alert('Never alerts when clicking on myLink or anotherDiv, why????');
bStopDefaultClickAction = true;
}
return bStopDefaultClickAction;
});
See my alert question above. I was under the impression that clicks bubble. And it somewhat does because the document actually receives my click and starts delegating. But the bubbling mechanism for clicks on myLink and anotherDiv doesn't seem to work as the if-statement doesn't kick in.
Or is it like this: clicks only bubble one step, from the clicked src element to the assigned delegation object (in this case the document)? If that's the case, then I need to handle the delegation like this:
$('.myDiv').click(function(e) {
//...as before
});
But this kind of defeates the purpose of delegation as I now must have lots of 'myDiv' handlers and possibly others... it's dead easy to just have one 'document' event delegation object.
Anyone knows how this works?
You should use live event from JQuery (since 1.3), it use event delegation :
http://docs.jquery.com/Events/live
So you code will be :
$(".myDiv").live("click", function(){
alert('Alert when clicking on myLink elements. Event delegation powaa !');
});
With that, you have all the benefices of event delegation (faster, one event listener etc..), without the pain ;-)
The event target will not change. You need to mirror what jquery live does and actually check if $eventElem.closest('. myDiv') provides a match.
Try:
$(document).click(function(e) {
var $eventElem = $(e.target);
var bStopDefaultClickAction = false;
if ( $eventElem.closest('.myDiv').length )
{
alert('Never alerts when clicking on myLink or anotherDiv, why????');
bStopDefaultClickAction = true;
}
return bStopDefaultClickAction;
});
Event.target is always the element that triggered the event, so when you click on 'myLink' or 'anotherDiv' you store a reference to these objects using $(e.target); So what you do in effect is: $('.myLink').is('.myDiv') which returns false, and that's why the alert() is not executed.
If you want to use event delegation this way, you should check wheter event.target is the element or any of its children, using jQuery it could be done like this:
$(e.target).is('.myDiv, .myDiv *')
Seems to work fine to me. Try it here: http://jsbin.com/uwari
Check this out: One click handler in one page
var page = document.getElementById("contentWrapper");
page.addEventListener("click", function (e) {
var target, clickTarget, propagationFlag;
target = e.target || e.srcElement;
while (target !== page) {
clickTarget = target.getAttribute("data-clickTarget");
if (clickTarget) {
clickHandler[clickTarget](e);
propagationFlag = target.getAttribute("data-propagationFlag");
}
if (propagationFlag === "true") {
break;
}
target = target.parentNode;
}
});