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.
Note: Not using jQuery, before you mark this as a duplicate make sure other Q/A is pure JS.
I set my event listener like this, which works perfectly when triggered via html:
document.getElementById('activitySelector').addEventListener('change', function() {
console.log("I work triggered by html but not js")
}
I'm adding additional functionality where I change the select value via javascript, which works in that the html updates, but the eventListener is never triggered:
document.getElementById("activitySelector").value = interactiveType
To achieve what you want you should create the event manually and dispatch it. It's not difficult, as you could see here: http://www.2ality.com/2013/06/triggering-events.html?m=1
This is my initial solution. Just have the event handler trigger your code wrapped as a function. That way you can just call that same function when updating via javascript.
As #dfsq has pointed out this is just how it works. Manually triggering the event would probably take more code than this method:
// All code originally in eventListener now in function
function onActivityChange() {
console.log("I work triggered by html and js")
}
// Call above function from eventlistener
document.getElementById('activitySelector').addEventListener('change', onActivityChange)
// Trigger same function after updating value
document.getElementById("activitySelector").value = interactiveType
onActivityChange()
My code
var post = {};
post.DivPostContent = $('.content');
post.DivPostContent.live({
mouseenter:
function()
{
var post_id = $(this).attr('data-post_id');
var content_id = $('#content' + '_' + post_id);
var link = $('#link' + '_' + post_id);
content_id.find('.post_ratings').hide();
content_id.find('.post_actions').show();
//I removed the click event on a whim, i have no clue why it works
link.unbind('click');
link.click(function(){
post.link_action(post_id);
});
},
mouseleave:
function()
{
//does something
}
});
post.link_action = function(){
//Does some Ajax request
}
Before i unbinded the click event from "Link" it called "post.link_action" four times, i was trying to get my head around why it does that. After hours of reading through my code again and again, i thought to myself, let's try removing the click event and i mistakenly put that line in the wrong place(out of frustration i guess). I ran the code, and viola! it worked! How? I have no clue.
Now my question is, why does unbinding the click event before adding it stop the process from repeating itself? I really would like to know why.
Thanks.
because every time your mouse enter the object post.DivPostContent it's binding a new click event to your link object; it triggered 4 times because you moused over 4 times.
forget .live & .click; use .on instead and bind one time & outside your mouseenter event or if you insist to bind it in there use a .off before
$elem.off("click").on("click",function() {});
but do it once and outside your mousenter
Now my question is, why does unbinding the click event before adding it stop the process from repeating itself?
The code:
link.click(function(){
post.link_action(post_id);
});
Adds a callback to the click event, if you register multiple times, like in your case onmouseenter you will end up with the same event firing multiple times.
The unbind function removes any previous callbacks to the specific event, so this why the callback fires only one time.
By the way, unless your jQuery version is 1.4.3 or less you shouldn't be unsing live.
Use on which is available from version 1.7 ore delegate which is avaiable from version 1.4.4.
I'm trying to make it so when an element gets focus it calls a function which then will take care of all other events - here is my code for now.
<span id="checkbox" class="checkbox" onFocus="cbHover(checkbox)"></span>
<script type="text/javascript">
function cbHover(id) {
if(document.getElementById(id).onClick) {
document.getElementById(id).style.backgroundPositionY = '-63px';
}
}
</script>
Obviously this isn't working :( So is there a way to keep the function running to listen for other events?
Thanks!
When the object is clicked, it is already focused. You can either skip the onFocus and replace it with onClick, or the other way around and remove if(document.getElementById(id).onClick) from the code, because you don't need it.
You are able to use two events: onFocus and onLostFocus. In onFocus event handler you are able to add onClick event to element:
document.getElementById(id).addEventListener('click',function_name,true);
In onLostFocus event handler you are able to remove event
document.getElementById(id).removeEventListener('click',function_name,true)
this is a bad idea even if you did get it to work you run the risk of applying multiple clicks on the same element. your best bet it to just apply the click event on dom ready I typically use jQuery
so if I where doing this in jquery i would do it like this
$(document).ready(function(){
$('.classname').click(function(){
// what to do onclick
});
});
The reason it isnt working is the parameter that is passed, should be enclosed in quotes.
It should be
onFocus="cbHover('checkbox')"
otherwise, javascript treats checkbox as a variable and tries to pass the value of the variable which is null.
What is the difference betwen setting the onclick function in this way:
obj.onclick=new Function('functionname')
and
obj.onclick=function(){ functionname();};
How can i set the onclick event removing all previrius attached? (using jquery or simply javascript)
i try something like this:
$(obj).unbind('click');
$(obj).click(function() {
functionname();
});
but the unbind seems to remove even the next attached events.
thanks
EDIT:
I set the click event using jquery:
function ON(){
$('#makecorr').unbind('click');//i unbind for some reason..
$('#makecorr').click(function() { OFF(); });
}
function OFF(){
$('#makecorr').unbind('click');//i want to remove prev attached fun
//and replace it with new event
$('#makecorr').click(function() { ON(); });
}
this doesnt work for me, when i click the object 'makecorr' it goes in loop , if i put an alert, it comes up infinitely
but when i use: '
function ON(){
$('#makecorr').get(0).onclick=new Function('OFF()');
}
function OFF()
{
$('#makecorr').get(0).onclick=new Function('ON()');
}
it works. strange where am i wrong?
This pair of lines:
$(obj).unbind('click');
$(obj).click(function() { functionname(); });
...if executed in the order above should result in just the handler you've defined there being attached. If you're seeing other behavior, it must be something else in the script.
Regarding
What is the difference betwen setting the onclick function in this way:
obj.onclick=new Function('functionname') and
obj.onclick=function(){ functionname();};
If you're dynamically adding handlers to an element and you're already using jQuery for other reasons, you don't want to use the onclick property at all; stick to the jQuery API, to avoid really confusing yourself. :-)
Even if you're not using jQuery, you almost never want to use new Function(...). There are only very special situations where you'd need that. Mostly stick to function() { functionname(); } (or just use functionname directly).