I want to do something on all clicks except on a certain element.
I've created a very simple example which demonstrates the issue: http://jsfiddle.net/nhe6wk77/.
My code:
$('body').on('click', ':not(a)', function () {
// do stuff
});
I'd expect all click to on <a> to be ignored, but this is not the case.
Am I doing something wrong or is this a bug on jQuery's side?
There's a lot going on in that code that's not obvious. Most importantly, the click event is actually attached to the body element. Since that element isn't an anchor, you'll always get the alert. (Event delegation works because the click event bubbles up from the a through all its ancestors, including body, until it reaches document.)
What you want to do is check the event.target. That will tell you the element that was actually clicked on, but the actual click event is still bound to the body element:
$('body').on('click', function (e) { // e = event object
if ($(e.target).is(':not(a)')) {
alert('got a click');
}
});
http://jsfiddle.net/y3kx19z7/
No this is not a bug but rather intended behaviour.
The event bubbles all the way up. By clicking the a node, you are still triggering it's parents event from the div node.
Read more about event bubbling in the W3C DOM Specification. Just search for "bubble".
You need to stop the event propagation of the a nodes. i.e.:
$('body').on('click', ':not(a)', function () {
// do something effectively
alert('you should not see me when clicking a link');
});
$("a").click(function( event ) {
// do nothing effectively, but stop event bubbling
event.stopPropagation();
});
JSFiddle: http://jsfiddle.net/nhe6wk77/6/
It's working as intended, here's why!
Use of the :not() selector is honored in delegated events, but it's an uncommon practice because of how events bubble up the DOM tree potentially triggering the handler multiple times along the way.
The jQuery API Documentation states that:
jQuery bubbles the event from the event target up to the element where the handler is attached (i.e., innermost to outermost element) and runs the handler for any elements along that path matching the selector.
Notice the phrase "and runs the handler for any elements along that path matching the selector".
In your example, jQuery is accurately not running the handler on the a element, but as the event bubbles up the tree, it runs the handler for any element that matches :not(a), which is every other element in the path.
Here is a clear example showing how this works: http://jsfiddle.net/gfullam/5mug7p2m/
$('body').on('click', ':not(a)', function (e) {
alert($(this).text());
});
<div class="outer">
<div class="inner">
Click once, trigger twice
</div>
</div>
<div class="outer">
<div class="inner">
<button type="button">Click once, trigger thrice</button>
</div>
</div>
Clicking on the link in the first block of nested divs, will start the event bubbling, but the clicked a element — a.k.a. the event target — doesn't trigger the handler because it doesn't match the :not(a) selector.
But as the event bubbles up through the DOM, each of its parents — a.k.a the event currentTarget — triggers the handler because they do match the :not(a) selector, causing the handler to run twice. Multiple triggering is something to be aware of since it may not be a desired result.
Likewise, clicking on the button in the second block of nested divs, will start the event bubbling, but this time the event target does match the :not(a) selector, so it triggers the handler immediately. Then as the event bubbles up, each of its parents matching the selector triggers the handler, too, causing the handler to run three times.
As others have suggested, you need to either bind an alternate handler that stops propagation on a click events or check the event target against the :not(a) selector inside your handler instead of the delegated selector.
$("body").click(function(e) {
if($(e.target).is('a')){
e.preventDefault();
return;
}
alert("woohoo!");
});
check the target of the click. this way you dont need to bind another event.
updated fiddle
Related
I have a table where i have bound all my elements with class="shift" to a click function.
Now, because I also need to use another click event on part of the element, I would like to unbind the click event on element when the mouse enters the element and rebind when i leaves (meant for some touch events and whatnot)
Now, I bind like this
$("table").on("touchstart mousedown",".shift", function(e){ ... })
But when i try to unbind on a specific element, say it has a class="selected" added to distinguish the current element i use:
$("table").off("touchstart mousedown",".shift.selected")
which does not work....
I can remove all the handlers at once, but it would be wasteful to remove all the handlers and reinsert them as soon as the mouse leaves.
So, is there a way to remove the handler on a single element after the event is bound to all current and future elements?
Thanks in advance!
You don't need to unbind the click event on the element when the mouse enters. I know, the element click event will trigger when you click an inner element with the click event bound, right ? you can stop that:
The click handler of the inner element must look like this:
$("some inner element").click(function(event) {
//That's what are you looking for ;)
event.stopPropagation();
//You code here
});
event.stopPropagation() will prevent the event from bubbling up the DOM tree, preventing any parent handlers from being notified of the event.
I've attached delegated event handlers to a number of elements on the page using a single selector. As the events are triggered for individual elements, I'd like to turn off only that element's event handler based on some conditional logic. That means I won't necessarily want to disable the event on the very first click. But I can't figure out how to do it without turning off all of them.
HTML:
<button>One</button>
<button>Two</button>
<button>Three</button>
JS:
$(document).on('click', 'button', function(ev) {
// doesn't work because argument needs to be a string
$(document).off('click', $(ev.target));
// doesn't do what I want b/c turns off events on all buttons, not just this one
$(document).off('click', 'button');
// doesn't work because event is on document, not button
$(ev.target).off('click');
});
jQuery's off documentation says I need to provide a string as the second argument, not a jQuery object ($(ev.target)), but if I provide a string, there's no value that refers only to the item clicked.
From jQuery's off documentation:
To remove specific delegated event handlers, provide a selector
argument. The selector string must exactly match the one passed to
.on() when the event handler was attached. To remove all delegated
events from an element without removing non-delegated events, use the
special value "**".
So how do I turn off a delegated event handler for a specific element?
Here's a JSFiddle of the code above
UPDATE: Added a few examples of options that don't work, based on initial answers provided.
After having read thru on the web, the answer is you can't! You can either remove all or none. A workaround could be something like the following.
$(document).on('click', '.btn', function (ev) {
alert('pressed');
$(this).removeClass("btn");
});
Demo#Fiddle
Sample HTML:
<button class="btn">One</button>
<button class="btn">Two</button>
<button class="btn">Three</button>
In addition to what lshettyl said (the current top post) - an additional work around is to bind a new event listener directly to the element that you're trying to remove the listener and call stopPropagation() therein.
What this will do is prevent the event from traveling up the DOM and reaching the event handler that is initially bound to the document. Also this will allow you to keep some functionality on the button click, such as an alert to the user that this button has already been clicked - or something to that effect.
$(document).on('click', 'button', function(ev) {
// Your logic to occur on button click
// Prevent further click on just this button
$(this).click(function(event) {
event.stopPropagation();
}):
});
Question: Do you have to use the delegated events? LIke LShetty said, it is not possible to remove a delegated event for a single element. You either remove the entire event delegation, or leave it. You could try using a different selector instead like in this example
$('button').on('click', function(ev) {
$('#output').append('Clicked! ');
$(this).off('click');
});
<script src="https://ajax.googleapis.com/ajax/libs/jquery/1.7.2/jquery.min.js"></script>
<button>One</button>
<button>Two</button>
<button>Three</button>
<div id="output"></div>
Is there anything wrong that can happen if I bind a null selector using on? It would simplify my code and allow me to chain a few things if I didn't have to explicitly check if the selector is null myself.
Any performance, security, or memory-leak implications if I do this a dozen times on my page?
$(document.body).on('click', null, function () { ... }
If you plan on dynamically adding elements, there is nothing wrong by binding on a higher element using the .on() method.
Keep in mind though you have to specify a selector that will ultimately define the dynamically added elements.
The code below will fire when a label is clicked.
$(document).on('click', 'label', function(e) {
alert('dynamically added label clicked');
});
This code will fire when any element is clicked.
$(document).on('click', null, function (e) {
alert('fired regardless what element you clicked');
});
From the jQuery docs:
A selector string to filter the descendants of the selected elements
that will call the handler. If the selector is null or omitted, the
handler is always called when it reaches the selected element.
If your problem is that the elements that raise the click event are dynamically added you can still use a direct event handler on body and catch those events.
The delegated event handler gives you the opportunity to filter out some of those click events, but it seems that's not the case since you are setting the selector to null.
For example, if you have a div and add buttons inside and add an event handler to the click event on the div you'll catch all the click events from all the buttons, even the ones added dynamically.
<div>
<input type="button" value="add button" id="buttonAddMore"/>
<span id="whatClicked"></span>
</div>
$('div').on("click", function(event){
$('#whatClicked').text("the id of the clicked element inside the div is: " + event.target.id);
});
This fiddle demonstrates this.
The delegated events have other subtleties, such as, they won't respond to events raised in the elements they are registered in, in this example that would be a click on the div, and that might be important.
Either way if you look at how the events are registered, in your case you can have a look by calling in the console $._data(document.body, "events") and have a look at the click event handler with your method and registered using the shorthand version (i.e. .click or on("click", function() {...})) you'll see that they produce the same object, except for the selector being null (.on("click", null...) in one case and undefined in the other (.click)
i got a problem
<div id='parent'>
<div id='child'>
</div>
</div>
what i want is when the child is clicked addClass,and when the rest of parent is clicked removeClass,so when i try to do
$('#child').click(function(){
$(this).addClass();
})
$('#parent').click(function(){
$('#child').removeClass();
})
its not working i think its because the child is actually inside the parent,so when the child is clicked the parent clicked right?
so how can i do that?
try this:
$('#child').click(function(evt){
evt.stopPropagation();
$(this).addClass("myClass");
});
You could use event.stopPropagation to prevents the event from bubbling up the DOM tree, preventing any parent handlers from being notified of the event.
$('#child').click(function(e){
e.stopPropagation();
$(this).addClass();
});
Several users have already suggested a good solution - here's an explanation of why it works:
When you click an HTML element (actually a DOM object...), the click event "bubbles" all the way up to the root element. For example, a click in #child also triggers a click in #parent, as you expected.
To stop this behavior, you need to call .stopPropagation() on the click event - that will tell the browser that you do not want the event to propagate, but keep it "local". Basically, when you've handled it here, you're done with it and don't want to see it again.
Conveniently, jQuery event handlers take the event as the first argument, so if you assign any function with the signature function (e) { ... }, you can stop event propagation by e.stopPropagation(); as others have suggested. In your case, you want
$('#child').click(function(e){
$(this).addClass();
e.stopPropagation();
});
$('#parent').click(function(){
$('#child').removeClass();
});
I am trying to stop some events but stopPropagation does not work with "live" so I am not sure what to do. I found this on their site.
Live events do not bubble in the
traditional manner and cannot be
stopped using stopPropagation or
stopImmediatePropagation. For example,
take the case of two click events -
one bound to "li" and another "li a".
Should a click occur on the inner
anchor BOTH events will be triggered.
This is because when a
$("li").bind("click", fn); is bound
you're actually saying "Whenever a
click event occurs on an LI element -
or inside an LI element - trigger this
click event." To stop further
processing for a live event, fn must
return false
It says that fn must return false so what I tried to do
$('.MoreAppointments').live('click', function(e) {
alert("Hi");
return false;
});
but that did not work so I am not sure how to make it return false.
Update
Here is some more information.
I have a table cell and I bind a click event to it.
$('#CalendarBody .DateBox').click(function(e)
{
AddApointment(this);
});
So the AddApointment just makes some ui dialog box.
Now the live code(MoreAppointments) sits in this table cell and is basically an anchor tag. So when I click on the anchor tag it first goes to the above code(addApointment - so runs that event first) runs that but does not launch my dialog box instead it goes straight to the (MoreAppointment) event and runs that code. Once that code has run it launches the dialog box from "addApointment".
Update 2
Here is some of the html. I did not copy the whole table since it is kinda big and all the cells repeat itself with the same data. If needed I will post it.
<td id="c_12012009" class="DateBox">
<div class="DateLabel">
1</div>
<div class="appointmentContainer">
<a class="appointments">Fkafkafk fakfka kf414<br />
</a><a class="appointments">Fkafkafk fakfka kf414<br />
</a><a class="appointments">Fkafkafk fakfka kf414<br />
</a><a class="appointments">Fkafkafk fakfka kf414<br />
</a><a class="appointments">Fkafkafk fakfka kf414<br />
</a>
</div>
<div class="appointmentOverflowContainer">
<div>
<a class="MoreAppointments">+1 More</a></div>
</div>
</td>
The short answer is simply, you can't.
The problem
Normally, you can stop an event from "bubbling up" to event handlers on outer elements because the handlers for inner elements are called first. However, jQuery's "live events" work by attaching a proxy handler for the desired event to the document element, and then calling the appropriate user-defined handler(s) after the event bubbles up the document.
(source: shog9.com)
This generally makes "live" binding a rather efficient means of binding events, but it has two big side-effects: first, any event handler attached to an inner element can prevent "live" events from firing for itself or any of its children; second, a "live" event handler cannot prevent any event handlers attached directly to children of the document from firing. You can stop further processing, but you can't do anything about processing that has already occurred... And by the time your live event fires, the handler attached directly to the child has already been called.
Solution
Your best option here (so far as I can tell from what you've posted) is to use live binding for both click handlers. Once that's done, you should be able to return false from the .MoreAppointments handler to prevent the .DateBox handler from being called.
Example:
$('.MoreAppointments').live('click', function(e)
{
alert("Hi");
return false; // prevent additional live handlers from firing
});
// use live binding to allow the above handler to preempt
$('#CalendarBody .DateBox').live('click', function(e)
{
AddApointment(this);
});
I've used such kind if code and it worked for me:
$('#some-link').live('click', function(e) {
alert("Link clicked 1");
e.stopImmediatePropagation();
});
$('#some-link').live('click', function(e) {
alert("Link clicked 2");
});
so, it seems to me, that now JQuery support stopImmediatePropagation with live events
Maybe you could check that the click event didn't occur on an a element:
$('#CalendarBody .DateBox').click(function(e) {
// if the event target is an <a> don't process:
if ($(e.target).is('a')) return;
AddApointment(this);
});
Might Work?
I'm using this:
if(event.target != this)return; // stop event bubbling for "live" event
I use
e.stopPropagation(); // to prevent event from bubbling up
e.preventDefault(); // then cancel the event (if it's cancelable)
I've used this in certain situations. Note: not always applicable, so assess for your needs as always:
html:
Click me
js (in your live event handler):
if(e.target.className == 'my-class-name') {
e.preventDefault();
// do something you want to do...
}
This way, my live event only 'runs' when a particular element type/classname attr is clicked.
The e.preventDefault() here is to stop the link I'm clicking moving the scroll-position to the top of the page.
Simply use **"on"** function to bind click event of child as well as parent element.
Example : $("#content-container").on("click","a.childElement",function(e){
alert("child clicked");
e.stopPropagation() ;
});
$("#content-container").on("click","div.parentElement",function(e){
alert("parent clicked");
});
( where content-container is the outer div containing both parent as well as child elements. )
Here only "child clicked" alert will occur.
Thanks.