I have an input type="image". This acts like the cell notes in Microsoft Excel. If someone enters a number into the text box that this input-image is paired with, I setup an event handler for the input-image. Then when the user clicks the image, they get a little popup to add some notes to the data.
My problem is that when a user enters a zero into the text box, I need to disable the input-image's event handler. I have tried the following, but to no avail.
$('#myimage').click(function { return false; });
jQuery ≥ 1.7
With jQuery 1.7 onward the event API has been updated, .bind()/.unbind() are still available for backwards compatibility, but the preferred method is using the on()/off() functions. The below would now be,
$('#myimage').click(function() { return false; }); // Adds another click event
$('#myimage').off('click');
$('#myimage').on('click.mynamespace', function() { /* Do stuff */ });
$('#myimage').off('click.mynamespace');
jQuery < 1.7
In your example code you are simply adding another click event to the image, not overriding the previous one:
$('#myimage').click(function() { return false; }); // Adds another click event
Both click events will then get fired.
As people have said you can use unbind to remove all click events:
$('#myimage').unbind('click');
If you want to add a single event and then remove it (without removing any others that might have been added) then you can use event namespacing:
$('#myimage').bind('click.mynamespace', function() { /* Do stuff */ });
and to remove just your event:
$('#myimage').unbind('click.mynamespace');
This wasn't available when this question was answered, but you can also use the live() method to enable/disable events.
$('#myimage:not(.disabled)').live('click', myclickevent);
$('#mydisablebutton').click( function () { $('#myimage').addClass('disabled'); });
What will happen with this code is that when you click #mydisablebutton, it will add the class disabled to the #myimage element. This will make it so that the selector no longer matches the element and the event will not be fired until the 'disabled' class is removed making the .live() selector valid again.
This has other benefits by adding styling based on that class as well.
This can be done by using the unbind function.
$('#myimage').unbind('click');
You can add multiple event handlers to the same object and event in jquery. This means adding a new one doesn't replace the old ones.
There are several strategies for changing event handlers, such as event namespaces. There are some pages about this in the online docs.
Look at this question (that's how I learned of unbind). There is some useful description of these strategies in the answers.
How to read bound hover callback functions in jquery
If you want to respond to an event just one time, the following syntax should be really helpful:
$('.myLink').bind('click', function() {
//do some things
$(this).unbind('click', arguments.callee); //unbind *just this handler*
});
Using arguments.callee, we can ensure that the one specific anonymous-function handler is removed, and thus, have a single time handler for a given event. Hope this helps others.
maybe the unbind method will work for you
$("#myimage").unbind("click");
I had to set the event to null using the prop and the attr. I couldn't do it with one or the other. I also could not get .unbind to work. I am working on a TD element.
.prop("onclick", null).attr("onclick", null)
If event is attached this way, and the target is to be unattached:
$('#container').on('click','span',function(eo){
alert(1);
$(this).off(); //seams easy, but does not work
$('#container').off('click','span'); //clears click event for every span
$(this).on("click",function(){return false;}); //this works.
});
You may be adding the onclick handler as inline markup:
<input id="addreport" type="button" value="Add New Report" onclick="openAdd()" />
If so, the jquery .off() or .unbind() won't work. You need to add the original event handler in jquery as well:
$("#addreport").on("click", "", function (e) {
openAdd();
});
Then the jquery has a reference to the event handler and can remove it:
$("#addreport").off("click")
VoidKing mentions this a little more obliquely in a comment above.
If you use $(document).on() to add a listener to a dynamically created element then you may have to use the following to remove it:
// add the listener
$(document).on('click','.element',function(){
// stuff
});
// remove the listener
$(document).off("click", ".element");
To remove ALL event-handlers, this is what worked for me:
To remove all event handlers mean to have the plain HTML structure without all the event handlers attached to the element and its child nodes. To do this, jQuery's clone() helped.
var original, clone;
// element with id my-div and its child nodes have some event-handlers
original = $('#my-div');
clone = original.clone();
//
original.replaceWith(clone);
With this, we'll have the clone in place of the original with no event-handlers on it.
Good Luck...
Updated for 2014
Using the latest version of jQuery, you're now able to unbind all events on a namespace by simply doing $( "#foo" ).off( ".myNamespace" );
Best way to remove inline onclick event is $(element).prop('onclick', null);
Thanks for the information. very helpful i used it for locking page interaction while in edit mode by another user. I used it in conjunction with ajaxComplete. Not necesarily the same behavior but somewhat similar.
function userPageLock(){
$("body").bind("ajaxComplete.lockpage", function(){
$("body").unbind("ajaxComplete.lockpage");
executePageLock();
});
};
function executePageLock(){
//do something
}
In case .on() method was previously used with particular selector, like in the following example:
$('body').on('click', '.dynamicTarget', function () {
// Code goes here
});
Both unbind() and .off() methods are not going to work.
However, .undelegate() method could be used to completely remove handler from the event for all elements which match the current selector:
$("body").undelegate(".dynamicTarget", "click")
I know this comes in late, but why not use plain JS to remove the event?
var myElement = document.getElementById("your_ID");
myElement.onclick = null;
or, if you use a named function as an event handler:
function eh(event){...}
var myElement = document.getElementById("your_ID");
myElement.addEventListener("click",eh); // add event handler
myElement.removeEventListener("click",eh); //remove it
This also works fine .Simple and easy.see http://jsfiddle.net/uZc8w/570/
$('#myimage').removeAttr("click");
if you set the onclick via html you need to removeAttr ($(this).removeAttr('onclick'))
if you set it via jquery (as the after the first click in my examples above) then you need to unbind($(this).unbind('click'))
All the approaches described did not work for me because I was adding the click event with on() to the document where the element was created at run-time:
$(document).on("click", ".button", function() {
doSomething();
});
My workaround:
As I could not unbind the ".button" class I just assigned another class to the button that had the same CSS styles. By doing so the live/on-event-handler ignored the click finally:
// prevent another click on the button by assigning another class
$(".button").attr("class","buttonOff");
Hope that helps.
Hope my below code explains all.
HTML:
(function($){
$("#btn_add").on("click",function(){
$("#btn_click").on("click",added_handler);
alert("Added new handler to button 1");
});
$("#btn_remove").on("click",function(){
$("#btn_click").off("click",added_handler);
alert("Removed new handler to button 1");
});
function fixed_handler(){
alert("Fixed handler");
}
function added_handler(){
alert("new handler");
}
$("#btn_click").on("click",fixed_handler);
$("#btn_fixed").on("click",fixed_handler);
})(jQuery);
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<button id="btn_click">Button 1</button>
<button id="btn_add">Add Handler</button>
<button id="btn_remove">Remove Handler</button>
<button id="btn_fixed">Fixed Handler</button>
I had an interesting case relevant to this come up at work today where there was a scroll event handler for $(window).
// TO ELIMINATE THE RE-SELECTION AND
// RE-CREATION OF THE SAME OBJECT REDUNDANTLY IN THE FOLLOWING SNIPPETS
let $window = $(window);
$window.on('scroll', function() { .... });
But, to revoke that event handler, we can't just use
$window.off('scroll');
because there are likely other scroll event handlers on this very common target, and I'm not interested in hosing that other functionality (known or unknown) by turning off all of the scroll handlers.
My solution was to first abstract the handler functionality into a named function, and use that in the event listener setup.
function handleScrollingForXYZ() { ...... }
$window.on('scroll', handleScrollingForXYZ);
And then, conditionally, when we need to revoke that, I did this:
$window.off('scroll', $window, handleScrollingForXYZ);
The janky part is the 2nd parameter, which is redundantly selecting the original selector. But, the jquery documentation for .off() only provides one method signature for specifying the handler to remove, which requires this middle parameter to be
A selector which should match the one originally passed to .on() when attaching event handlers.
I haven't ventured to test it out with a null or '' as the 2nd parameter, but perhaps the redundant $window isn't necessary.
I've looked all over the internet with everyone giving the same answer
$(document).on('click', '#targetID', function() {
// do stuff
});
instead of
$('#targetID').click(function() {
// do stuff
});
This is nice and it works fine, if you have a click event. But within that on click function, the part where it says do stuff, how can I now target an appended element? For instance say I append 2 divs back to back.
<div id="mainDiv"></div>
<script>
socket.on('event', function (data) {
$('#mainDiv').append ('<div class="1st" id="'+data.id+'">one</div>
<div class="2nd" id="'+data.id+'">second</div>');
});
$(document).on('click', '.1st', function() {
//and right here i would like to`enter something like
$('.2nd').css('background-color','yellow');
}
</scirpt>
This however seems not to work because to my knowledge, this element hasn't been added to the DOM. So what should I do? Should i use angular.js for this?
PS I've also tried adding the entire appended content into a variable first before appending that variable. and then using variable.find to find the element within to no avail. The variable only has context within that function, but is null in the on click function. Thanks in advance for any information that broadens my understanding of this.
The delegation of 'on' is correct. Once the div element exists in the dom, clicking should work. My only concern is you have named your classname beginning with a number. Maybe name it with an alpha character followed by a number.
The difference between the 2 is the concept of event binding vs event delegation.
$('#targetID').click(function() { is event binding which works on elements as long as they exist in the markup when the page or document loads.
$(document).on('click', '#targetID', function() { is event delegation which means the event would listen to the document for the click event on the element with ID targetID if it exists in the DOM when the page loads or if it is dynamically added.
So In your case, its event delegation since you are dynamically adding the elements. But in order to make it work, you need to register the listener on the document ready event for the document to listen to the event on the element #targetID
<script>
$(document).ready(function() // Add this
{
socket.on('event', function (data) {
$('#mainDiv').append ('<div class="1st" id="'+data.id+'">one</div><div class="2nd" id="'+data.id+'">second</div>');
});
$(document).on('click', '.1st', function() {
//and right here i would like to`enter something like
$('.2nd').css('background-color','yellow');
});
});
</script>
Here's an example : https://jsfiddle.net/nobcp0L7/1/
Maybe i should be more specific.
I've a javascript function, called from here:
<input id="Text1" type="text" onkeyup="Trova('Text1');" />
The function, search into an array and, with jquery, draws new rows into a table (ID #tabdest):
$("#tabdest").append('<tr><td class="preview" nome="' + nomi[i] + '" >' + nomi[i] + '</td></tr>');
Everythings is ok until now. Into my .js file I've this function that shoud be executed:
$(document).ready(function () {
$(".preview").mousemove(function (event) {
...
This function works correctly if I write a table manually but doesn't if jQuery write it.
I'm sorry for my terrible English, hope to find help
Thanks anyway
Use .on()
As elements are added dynamically you can not bind events directly to them .So you have to use Event Delegation.
$("#tabdest").on('mousemove','.preview',function(event){ ... });
Syntax
$( elements ).on( events, selector, data, handler );
Although the other answers have correctly identified that you should be using event delegation (through the use of jQuery's on function) I wanted to explain a bit about how your code is currently working.
$(document).ready(function () {
$(".preview").mousemove(function (event) {
...
Translated into words this is: When the document is ready search for all elements with class "preview" and add an event handler to these elements for the mouse move event. jQuery doesn't do magic.
$('.preview')...
is basically doing
document.getElementsByClassName('preview')
It's not doing any kind of mapping or binding to the DOM. This means when you add a new element with the class "preview" the code that added the event handlers would need to run again to pick this new element up.
Using:
$("#tabdest").on('mousemove', '.preview', function(e) { });
Binds the event handler to the "tabdest" element (which doesn't change) and when a user clicks on a child of this element (one of your newly created elements) the event bubbles up the DOM and runs this function.
Since the preview tabel cell is added dynamically, you need to use event delegation to register the event handler:
// New way (jQuery 1.7+) - .on(events, selector, handler)
$('#tabdest').on('mousemove', '.preview', function(event) {
alert('testlink');
//....
});
This will attach your event to any table cell with class preview within the #tabdest table element, reducing the scope of having to check the whole document element tree and increasing efficiency.
I need some help with the callbacks. For some reason, they don't work really well.
I'm making a game with jQuery. I have a <div id='button'></div> for all the buttons that are going to be in the game. The game is going to have two buttons that make actions, and a question on top of it. The question is controlled by a <h3 id='text'></h3>. What I want to know, is that for some reason I can't set callback functions to the button's ID's. In example,
I'd have the yes or no, that have their own id's set through jQuery like this:
$('#button').html('<button id='yes'>Yes</button><button id='no'></button>');
But for some reason, I would be able to set this:
$('yes').click(function(){
//function I would want
});
Of course, that's not what my code has, that was just an example. Here's the real code:
$(document).ready(function(){
$('#main,#batman,#car,#cop,#hobo,#knife,#gangfight,#ganggun,#gangknife,#blood,#hr').hide(-100);
var hr=$('#hr');
var main=$('#main');
var batman=$('#batman');
var car=$('#car');
var hobo=$('#hobo');
var cop=$('#cop');
var knife=$('#knife');
var gangfight=$('#gangfight');
var ganggun=$('#ganggun');
var gangknife=$('#gangknife');
var blood=$('#blood');
var text=$('#text');
var button=$('#button');
$('#start').html('Are you ready to play?');
$('#button').html('<button id="yes">Yes</button><button id="no">No</button>');
$('#yes').click(function(){
$('#yes,#no').hide(function(){
$('#start').hide();
main.fadeIn(-100);
hr.fadeIn(-100,function(){
text.delay(1000).html("You were just wandering around in the streets of new york, when suddenly.. You see batman!! You've never really liked him, what do you do?")
button.html('<button id="fight">Fight</button><button id="leave">Leave</button>',function(){
batman.fadeIn(1000);
$('fight').click(function(){
});
$('leave').click(function(){
text.fadeOut(function(){
text.text('Good call. As you leave, you encounter a hobo. What do you do?');
});
});
});
});
});
});
$('#no').click(function(){
$('#yes,#no').hide();
$('#start').text('Oh, okay then. Come back later!');
});
});
I'm just wondering.. How can I set callback functions to the 'fight' and 'leave'.
If you're wondering why there's all these variables at the start, those are just the images and characters.
You can't set a click handler on an element that doesn't exist. What you should do is use .on to bind a element further up the tree. Something like:
$("#someparentelement").on("click", "#yes", function() {
// your code
});
Which version of jQuery are you using? You should probably use jQuery.on() in this situation since your click handler code probably gets executed before the button is actually available in the DOM.
$("#button").on("click", "#yes", function (event) {
// Your yes-button logic comes here.
});
For more details and possibilities, read about the .on(events [, selector ] [, data ], handler(eventObject)) method in the jQuery documentation:
If selector is omitted or is null, the event handler is referred to as direct or directly-bound. The handler is called every time an event occurs on the selected elements, whether it occurs directly on the element or bubbles from a descendant (inner) element.
When a selector is provided, the event handler is referred to as delegated. The handler is not called when the event occurs directly on the bound element, but only for descendants (inner elements) that match the selector. 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.
In this case, you want to delegate the event since your element is not yet available in the DOM when you're binding the event.
Don't use the click(), use on('click') and attach it to the document.
Creating a handler this way, will ensure that any new elements will be able to trigger the event.
$('fight') selects fight tag, not the tag with fight id. Try to use $('#fight') instead.
I'm trying to use 'click' on a dynamically generated DOM. I know that I can just use live or on, however my dynamically generated content is within multiple dynamically generated pieces of content and live/on no longer works.
So my code looks something like this but with more elements before El_b:
El_a = document.createElement("li");
El_b = document.createElement("a");
El_b.id = "myEl";
El_a.appendChild(El_b);
Is there a way to make this work?
PS: I've also tried the livequery jQuery plugin.
As far as delegation is concerned, you always have at least one static DOM element available to you, which is the document. If you can't find a closer element to delegate to, delegate to this.
However, delegation seems to be unnecessary here. The entire process of creating your elements and attaching listeners could be condensed to:
var a = $("<li/>").append($("<a/>").attr("id", "myElement")).click(function () {
alert('hello');
});
If, as you say, you cannot change the object creation, you can still select it by its ID and attach the listener:
$('#myElement').click(function () {
alert('hello');
});
Also, those are document fragments, not documents proper, and certainly not DOMs.
If you want to bind a function on the click event on El_b, you can just do this :
$(El_b).click(function() {
// Your code here
});
But you can use on i think. Even if you create multiple DOM elements. You can use the document or the body. Example :
$('body').on('click', 'li a.my_class', function() {
// Your code here
});