jwerty key unbinding - javascript

taken from: https://github.com/keithamus/jwerty
Does anyone know how to unbind after setting up a .key binding?
As a test, I want this set globally when something is selected
jwerty.key('↑', function(e) {
e.preventDefault();
alert('up');
});
then unbound when that object is unselected. That stuff is already set up, inside that unselect statement though I want to call the jwerty unbind but can't figure out how.
but when I a) don't know how to unbind it explicitly or b) if I try to change it to a different anonymous function I still see the alert.

If you want a global key handler that can be removed, you have to bind it using jQuery http://jsfiddle.net/mendesjuan/LxQ4H/2/
function doit() {
alert('up');
}
// to bind use namespaces so it can be unbound without removing
$(document.body).bind('keydown.test', jwerty.event('↑', doit));
// a button that unbinds the key handler
$('#btn').click(function(){
$(document.body).unbind('keydown.test')
});
If you want the key handler to be scoped to an HTML element, you need to set the listener on the element, not globally. This will only fire if the element that it's bound to has focus. Just pass in a selector to bind a shortcut local to that element http://jsfiddle.net/mendesjuan/LxQ4H/
jwerty.key('⌃+⇧+P/⌘+⇧+P', function () { [...] }, this, '#myinput');
If your element doesn't take focus by default (a div), you need to make it focusable by doing the following. http://jsfiddle.net/mendesjuan/LxQ4H/1/
// or 0, 1,2 3 if you want it to be tabbable
document.getElementById('#mydiv').tabIndex = -1;
These code samples came from https://github.com/keithamus/jwerty (same link you already mentioned)

If you have jQuery available, as Juan Mendes mentioned, you can use jQuery's bind() method, with jwerty.event.
However there is another way to solve this. Using the current code you provided;
jwerty.key('↑', function(e) { e.preventDefault(); alert('up'); });
jwerty's internals will do the bind for you, but will add it under a special "keydown.jwerty" namespace. (See this line of the codebase). So, following the code you already have, you just need to do this:
$(document.body).unbind('keydown.jwerty');
The cool thing about using namespaces in jquery is that you can bind all jwerty events by also doing this:
$(document.body).unbind('.jwerty');

Related

preventing an inline script from running [duplicate]

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.

How to unbind from click event? [duplicate]

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.

Idiomatic way to set property to function value using jQuery

To hopefully head off the "primarily-opinion-based" close-button-clickers, I'm not looking for opinions on the "best" way to do this; I'm just wondering if there is a more straightforward solution that I'm missing.
My goal is to add the same onclick method to all of the (hundreds of) checkboxes on my page. My first attempt at a jQuery solution was this:
$('input[type="checkbox"]').prop('onclick', function(){alert("Boop!");})
But that runs into the computed-value behavior of $.prop() and calls the function immediately for each checkbox.
So I can do this:
$('input[type="checkbox"]').prop('onclick', function(){return function() {alert("Boop!");}})
But that feels awfully workaround-y. Alternatively, I could do this:
$('input[type="checkbox"]').each(function(_, cb) {
cb.onclick = function(){alert("Boop!");};
});
But that seems uncharacteristically manual for jQuery.
So am I missing a more straightforward solution?
Declare the function and then simply refer to it by name:
function handler() { alert("Boop!"); }
$("input[type='checkbox']").on("click", handler);
Note that you shouldn't be setting up event handlers by setting the "onfoo" properties.
edit — if what you want to avoid is adding the handler over and over again, use delegation:
$("body").on("click", "input:checkbox", handler);
That creates only one event handler registration. As "click" events bubble up the DOM to the body, jQuery will check to see which ones targeted elements that match the selector, and invoke your handler for those that do. (Opinion — I've mostly adopted the practice of exclusively using body-level delegation for all events. It makes things a lot less messy.)
you have to write event no use prop:
$('input:checkbox').on('click', function(){alert("Boop!");})
i will suggest to use change event for checkbox not click:
$('input:checkbox').on('change', function(){
if(this.checked)
{
alert("checked");
}
});

How can I remove an attached jQuery function programatically?

In $.ready() I have declared a click function as shown below
$(document).ready(function(){
$("#btnClk").click(function(clkevent){
//Doing Something Here
clkevent.preventDefault();
});
});
I want to remove this click() from $("#btnClk") in another javaScript function. How can I do this?
One of the problems with the proposed solutions is they remove all click event handlers registered, which may not be desired.
A solution to this is to separate the handler method out to a common scope shared by the both the participating methods then use that method reference along with .off() to resolve this
function btnclickHandler(clkevent){
//Doing Something Here
clkevent.preventDefault();
}
$(document).ready(function(){
$("#btnClk").click(btnclickHandler);
});
$("#btnClk").off('click', btnclickHandler);
Old School
$("#btnClk").unbind('click');
New School
$("#btnClk").off('click');
To register a click handler you should be using .on('click', ...) instead of .click - the latter can cause confusion because the same function is also used to trigger a click event.
To unregister the handler, use .off('click')
Please see the caveats at http://api.jquery.com/off/ regarding function handlers, name spaces, etc (my emphasis):
If a simple event name such as "click" is provided, all events of that type (both direct and delegated) are removed from the elements in the jQuery set.
and
A handler can also be removed by specifying the function name in the handler argument.
Note that in the latter case you can't specify the function name if the function never had a name in the first place, as in the code in the question where the handler is an anonymous function.
You can use unbind for this .
$('#btnClk).unbind('click');
almost same question
You can do this using off():
$('#btnClk').off('click');
This will remove all click event handlers from the btnClk.

JavaScript - All onClick events are not working?

Alright, so I'm making a Facebook-style chat. But that doesn't really matter.
See here:
http://jsfiddle.net/SkHme/7/
Nice and pretty, right? Well, there's a problem. Notice this line:
<div class="conversation EmperorCuzco" onclick="setActive('EmperorCuzco')">
See the onclick attribute? Well, it's not working. However, I have confirmed that the function itself DOES work. (if you run it just like that in the JavaScript, it runs like a dream) I have further confirmed that the function is not the problem by attempting to replace the onclick value with a simple alert('blah'), but that doesn't work either.
So, what's up? I'm guessing that something in my JavaScript is somehow disabling something, but I have absolutely no idea what it could be, nor how I could go about fixing it. I did some web searching, but couldn't find anything that helps.
What's going on?
Your setActive function is defined inside the scope of the $(document).ready handler. Move the function outside that function so that it is in the global scope.
Right now it looks like this:
$(document).ready(function()
{
// ...
function setActive(new_conversation)
{
// ...
}
});
Now change that to:
$(document).ready(function()
{
// ...
});
function setActive(new_conversation)
{
// ...
}
Really though, you should separate your content from your interactions and bind those event handlers in your script itself. Something like:
// Refers to the last clicked conversation *button*
// Initialize to empty jQuery object
var $active_conversation = $([]);
// Binding on #chat, targeting click events on .conversation_button children
$("#chat").on("click", ".conversation_button", function() {
// Hide currently active conversation
$active_conversation.hide();
$active_conversation.siblings('.conversation_button').removeClass("selected");
// Set as currently active conversation button
// Note: this refers to the clicked <div class="conversation_button">
var $this = $(this);
$active_conversation = $this.siblings('.conversation');
// Show this conversation
$active_conversation.show();
$this.removeClass("alert").addClass("selected");
});
Some advantages of this approach:
You don't need different classes for different conversations. By storing the actual conversation DOM element (as a jQuery object) in $active_conversation, the conversation can be identified without any extra processing.
You can add and remove whole list items with a conversation without assigning new event handlers. In the sample above, the event handler for all .conversation_button elements is defined at the level of #chat. For more about this binding mechanism, read up on .on (or .delegate for pre-1.7).
Here, have an updated fiddle! :-)
If all you say is really true (bad mistakes happen), the only thing that can make this is that an other event handler which takes your event before uses stopPropagation() or return false;
A quick check that can do is replace onclick with onmousedown or onmouseup, and see if you alert become visible.

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