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.
$(".quantidade").on("change blur", function() {
if ($(this).val().length) {
validateField("quantidade");
} else {
invalidateField("quantidade");
showGeneralMessage("É necessário preencher a quantidade!", "danger");
}
});
It works just fine, until a new item is added with append:
$(".btn-add-produto").click(function() {
...
$("#listaProdutosPedido").append(content);
...
});
This "content" includes input with the same class. After this html piece is added, the class selector does not apply to it. I guess it happens because when the document is ready, that piece of HTML does not exist. How do I "reload" the javascript / document so that the selector works even with future references? I've tried to check with setInterval(), but it does not work as well...
You need to use .on() delegated event syntax. In event delegation, you attach the event to a parent element. Internally, jQuery relies on the events ability to bubble up the DOM tree. When an event of the specified type with the e.target property matching your delegated selector is found, your event is fired.
To accomodate this change, modify your code like so:
$(document).on("change blur", ".quantidade", function() {
if ($(this).val().length) {
validateField("quantidade");
} else {
invalidateField("quantidade");
showGeneralMessage("É necessário preencher a quantidade!", "danger");
}
});
Please note, delegating at this high of a level is extremely inefficient. document should be changed out for the closest parent element that contains the newly appended content. In this case, I used it to demonstrate how the process occurs because there was not HTML DOM tree output specified in your question. When implementing this into your system, I encourage you to update the document selector accordingly.
I have kind of strange problem.
I'm trying to add a couple of events to som DOM elements (all existing, some initially hidden:
$self.on("focus", function () {
$self.next().css("display", "inline-block");
});
$self.on("blur", function () {
$(this).next().hide();
});
$self.parent().find(".icon-ok").on("click", function() {
console.log("icon.ok")
});
You can see the relevant part of the DOM here (self is the span user-name):
Later on, the element eventually because visible and I can click on it. However, the event handler is never called. If I remove the blur event, than the click event works. However, I need both.
What's going on here?
How can I fix it?
Looks like the blur cancels out the click (due to event order) but using mousedown instead of blur may help you get both.
UPDATE: Added code based on comment
$self.parent().find(".icon-ok").on("mousedown", function() {
console.log("icon.ok")
});
Your problem might be the classic delegation problem, where in the element is not available in the DOM when the event is bound.
Delegate the event and see if that solves your problem.
$self.on("click", ".icon-ok", function() {
console.log("icon.ok")
});
User $self if that element is visible or any closest ancestor that you can find which is always present in the DOM.
I'm using the jQuery Mobile option allowSamePageTransition, which enables me to go from
page A > page A > page A ...
I need this to allow browsing through a catalogue of items. My problem is, the items need some form of interaction and I used to attach the interaction binding to document, because it is set before the elements affected are generated.
However, reloading the same page over and over again will re-bind my event handlers every time I reload.
My first idea was to use .off when the page is being hidden, but reloading a page #foo, will trigger pagehide on the same page being shown, so all bindings set on
$(document).on("pagebeforeshow.foo_events", "#foo", function(e) {
// bind when shown
});
will be unbound again by the previous #foo being hidden
$(document).on("pagehide", "#foo", function (e) {
$(this).off(".foo_events");
// removes bindings on #foo being hidden AND shown
});
The only solution I have come up with is plastering the document with classes, which I don't like doing:
priv.setBindings = function (param) {
var doc = $(document);
doc
.filter(function() { return $(this).is(".e_gallery") !== true; })
.on("pagebeforeshow.gallery", param.pageId, function (e) {
doc.addClass(".e_gallery");
// run stuff
});
};
But I'm no fan of attaching classes to the dom.
Question:
Is there a way to prevent multiple event bindings set on $(document) when going to the same page over and over again WITHOUT toggling classes?
Solution 1
Best solution would be to use pageinit to bind events. If you take a look at an official documentation you will find out that pageinit will trigger ONLY once, just like document ready, so there's no way events will be bound again. This is best solution because you don't have processing overhead like when removing events with off method.
Working jsFiddle example: http://jsfiddle.net/Gajotres/AAFH8/
Of course this will fail in case multiple HTML solution is used.
Solution 2
Remove event before you bind it:
$(document).on('pagebeforeshow', '#index', function(){
$(document).off('click', '#test-button').on('click', '#test-button',function(e) {
alert('Button click');
});
});
Working jsFiddle example: http://jsfiddle.net/Gajotres/K8YmG/
Solution 3
Use a jQuery Filter selector, like this:
$('#carousel div:Event(!click)').each(function(){
//If click is not bind to #carousel div do something
});
Because event filter is not a part of official jQuery framework it can be found here: http://www.codenothing.com/archives/2009/event-filter/
This is probably best solution because event is going to be bound ONLY once.
Solution 4
Probably an easiest of them all.
$(document).on('pagebeforeshow', '#index', function(){
$(document).on('click', '#test-button',function(e) {
if(e.handled !== true) // This will prevent event triggering more then once
{
alert('Clicked');
e.handled = true;
}
});
});
Working jsFiddle example: http://jsfiddle.net/Gajotres/Yerv9/
This is a 180 percent different solution then solution 3, in this case event is going to be bound numerous times but it will be allowed to execute only once.
More info
If you want to find more about this problem take a look at this article, working examples are included.
I am trying to make simple list with ability to add and delete elements. For now I am working on adding and performing a simple action on each of list elements object (existing and added). Unfortunately I have met some difficulties with that. I am able to modify objects that are created at the beginning, but not one added during "webpage working".
First of all my idea was to add AJAX to this, but I don't think it is the easiest way.
I think that some time ago (I don't remember where) I read how to make this work, but now I don't know. I would be really glad if someone would help me with this or at least give a link to good explanation of this.
There is what I have done so far (well this is mostly just a scratch, but the main idea is in it): http://jsfiddle.net/sebap123/pAZ7H/0
$("li").click(function() {
$(this).text("new text");
});
$("#addButton").click(function() {
$(".list").append(
$('<li>').append($('<span>').append("added li")));
});
Thank you for all responses.
You just need to use event-delegation, with the on() method:
$("ul").on('click','li', function() {
$(this).text("OK");
});
JS Fiddle demo.
The problem you were experiencing is that jQuery can only directly bind events to already-present elements (present at the point of event-binding); the on() approach binds the action to the element to which the new content is added (or an ancestor element of the newly-added elements), identifies the events to listen for 'click' (a space-separated list of events), that match the selector (li) and then the function performs the required actions.
If you're using jQuery 1.7 (or later) on() should be used, for versions of jQuery < 1.7, delegate() should be used instead (which does more or less the same thing, but reverses the event-list and the selector parameters):
$("ul").delegate('li', 'click', function() {
$(this).text("OK");
});
JS Fiddle demo.
References:
delegate().
on().
Need to use event delegation here..
Try this
$("ul").on('click' , 'li', function() {
$(this).text("OK");
});
The problem with the previous click event is that events are only attched to the current element's on the page..
But when you create a new element , no events are attached to the element.
You have two options here.. Either to delegate your event i.e; add the event listerner to the element's ancestor ..
Or add the event once the element is created..
2nd Approach
var clickEvent = function() {
$('li').unbind().on('click', function() {
$(this).text("OK");
});
}
clickEvent();
$("#addButton").click(function() {
$(".list").append(
$('<li>').append($('<span>').append("Press me - I am new!")));
clickEvent();
});
In the second approach you are binding unbinding and binding the new event to all the elements once a new element is added..
Binding and again rebinding of events is a bad design pattern
FIDDLE
2nd APPROACH