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'm facing this weird issue with off() and on() event binding to a select dropdown:
If I unbind and then rebind the change event to the select dropdown I won't be able to change the dropdown shown value. In other words, the selected value is not updated properly in the dropdown, even if the change event is triggered.
If I remove the off() part, leaving only the event bounding with on(), everything works fine but obviously I'm not able to prevent the binding of the same event more than once.
See a live example here http://jsfiddle.net/z7o11exs/
Test case:
use the dropdown (it works! the selected value is correctly show in the dropdown)
refresh page. click on the first button (off/on) and then use the dropdown. It does not work properly as the selected value does not change
refresh page. click on the second button (only on) and then use the dropdown. It does work as expected. side effect: clicking n times on the 2nd button bounds n times the change event to the dropdown element
Here's the code:
//--- This binds the event to the element
function bindEvent(){
$("#myselect").on("change", function(){
console.log("change");
});
}
//--- remove any change event previously added, then rebind it
function rebindEvent(){
$("#myselect").off("change").on("change", function(){
console.log("change");
});
}
Thanks in advance
Try to use namespacing:
//--- This binds the event to the element
function bindEvent(){
$("#myselect").on("change.something", function(){
console.log("change");
});
}
//--- remove any change event previously added, then rebind it
function rebindEvent(){
$("#myselect").off("change.something").on("change", function(){
console.log("change");
});
}
As #Karl said, using namespace is to:
Giving a name to your event allow you to identify that event. So when using .off, you can target a specific event to turn off.
You have to call .selectmenu("refresh") when you remove change binding. Because by default, change is attached to selectmenu as mentioned here. So if you remove it, you interrupt jQuery Mobile widget from "refreshing" to visually display the value.
See it working here.
function rebindEvent(){
$("#myselect").off("change").on("change", function(){
$(this).selectmenu("refresh");
});
}
What I'm trying to achieve is to keep track of any changes (e. g. user input, field added, ...) within a <table>-element.
In my specific scenario users can edit fields, add rows, add fields, remove fields and rows, select something in <select>-elements, etc.
Of course I could just attach my "change"-listener to all of those actions, but I think there must be a better way.
I tried attaching a $('#myTable tbody').change()-listener to it, but that doesn't fire...
Maybe some of you know of a way to keep track of table changes without having to subscribe to every possible user action manually?
You can use Jquery liveQuery Plugin
Below is the example for mouse over and mouse out. you can do it for all the events likewise
$('table')
.livequery(function(){
// use the helper function hover to bind a mouseover and mouseout event
$(this)
.hover(function() {
$(this).addClass('hover');
}, function() {
$(this).removeClass('hover');
});
}, function() {
// unbind the mouseover and mouseout events
$(this)
.unbind('mouseover')
.unbind('mouseout');
});
Edit: As I understand it, jQuery 1.4+ should actually support the described behavior. I'll leave the rest of my post for reference.
You can add the event to every changeable element, because that is where they are fired. However, you won't have to do it manually:
$('#myTable input, #myTable select, ...).change(...)
If, as you said, there are elements added later on, you might want to look into the .live method that allows you to bind event listeners to elements that are to be created later on.
To answer my own question:
I decided on doing it kinda like #mdsl suggested:
I now listen for changes like this:
$('#myTable tbody').on('focusout', 'input, select, checkbox', myListener);
I have a search suggestion box that I hide when the search text box loses focus. This works great, except that when I click one of the suggestions the click event for that suggestion does not fire.
searchText.focusout(function () { $("#search-suggestions").hide(); });
I also tried:
searchText.focusout(function () { $("#search-suggestions").css("visibility", "hidden"); });
I tried commenting out the hide on unfocus code and the click events then worked fine.
(Basically, the blur event happens before the click on the suggestion can be registered, such that the element I attempted to click is not on the screen when the clicm does register)
here's the click event code:
//Called after the ajax load
$("#search-suggestions").find("a").click(function () { alert("hi"); })
I also tried rendering this on the server but it failed as well:
Search Suggestion
If any one has any suggestions I would appreciate it. Thanks!
You could try to define something like this:
//this goes where you first binding focusout handler
searchText.focusout(onFocusOut);
//this is a usual function
function onFocusOut() {
$("#search-suggestions").hide();
}
//this could be defined after you draw the search-suggestions control
$("#search-suggestions").hover(function() {
//this is hover in handler; unbind focusout from searchText
//something like that:
$("#searchText").unbind('focusout', onFocusOut)
}, function() {
//this is hover out handler; bind focusout to searchText
//something like that:
$("#searchText").bind('focusout', onFocusOut)
});
you could also use live (http://api.jquery.com/live/) to define hover handler for #search-suggestions, depending on what exactly you need.
This will make your search suggestions stay visible when clicking them. In click handler you can then hide them.
Try just making it invisible.
Change $('#my_search_box').hide(); to $('#my_search_box').css('visibility','hidden');
If you have surrounding DOM elements that need to act as if the search box is gone, you can just assign it an absolute position as well.
Try using .css('visibility', 'hidden') instead of .hide which uses display:none.
I need to add a color picker to some input elements.
I'm using:
$(".element").colorPicker(){ ... }
This works perfectly.
The problem is that the page has a AJAX form, which - when submitted - will overwrite the previous form with a new one (new input fields etc). After that the colorPicker stops working.
So how can I fire that function to the newly created inputs too?
Just reattach the invocation in the ajax callback, since I don't believe there is a reliable event you can use to .live or .delegate it, without revealing more information.
I believe this might work:
$(".element").live('click focus', function () {
var $this = $(this);
if (!$this.data('hasColorPicker')) {
$this.colorPicker({ /* ... */ }).data('hasColorPicker', true);
$this.click(); // trigger the color picker - assuming it binds itself to the click event
}
});
What meder says is good, but also, if you are creating the new elements by copying existing ones, consider using $.clone(true) to make your copies and it will carry over existing event bindings too.