Right way to prevent additional events [duplicate] - javascript

They seem to be doing the same thing...
Is one modern and one old? Or are they supported by different browsers?
When I handle events myself (without framework) I just always check for both and execute both if present. (I also return false, but I have the feeling that doesn't work with events attached with node.addEventListener).
So why both? Should I keep checking for both? Or is there actually a difference?
(I know, a lot of questions, but they're all sort of the same =))

stopPropagation prevents further propagation of the current event in the capturing and bubbling phases.
preventDefault prevents the default action the browser makes on that event.
Examples
preventDefault
$("#but").click(function (event) {
event.preventDefault()
})
$("#foo").click(function () {
alert("parent click event fired!")
})
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<div id="foo">
<button id="but">button</button>
</div>
stopPropagation
$("#but").click(function (event) {
event.stopPropagation()
})
$("#foo").click(function () {
alert("parent click event fired!")
})
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<div id="foo">
<button id="but">button</button>
</div>
With stopPropagation, only the button's click handler is called while the div's click handler never fires.
Where as if you use preventDefault, only the browser's default action is stopped but the div's click handler still fires.
Below are some docs on the DOM event properties and methods from MDN:
event.cancelBubble
event.preventDefault()
event.returnValue
event.stopPropagation()
For IE9 and FF you can just use preventDefault & stopPropagation.
To support IE8 and lower replace stopPropagation with cancelBubble and replace preventDefault with returnValue

Terminology
From quirksmode.org:
Event capturing
When you use event capturing
| |
---------------| |-----------------
| element1 | | |
| -----------| |----------- |
| |element2 \ / | |
| ------------------------- |
| Event CAPTURING |
-----------------------------------
the event handler of element1 fires first, the event handler of element2 fires last.
Event bubbling
When you use event bubbling
/ \
---------------| |-----------------
| element1 | | |
| -----------| |----------- |
| |element2 | | | |
| ------------------------- |
| Event BUBBLING |
-----------------------------------
the event handler of element2 fires first, the event handler of element1 fires last.
Any event taking place in the W3C event model is first captured until it reaches the target element and then bubbles up again.
| | / \
-----------------| |--| |-----------------
| element1 | | | | |
| -------------| |--| |----------- |
| |element2 \ / | | | |
| -------------------------------- |
| W3C event model |
------------------------------------------
Interface
From w3.org, for event capture:
If the capturing EventListener wishes to prevent further processing of
the event from occurring it may call the stopPropagation method of the
Event interface. This will prevent further dispatch of the event,
although additional EventListeners registered at the same hierarchy
level will still receive the event. Once an event's stopPropagation
method has been called, further calls to that method have no
additional effect. If no additional capturers exist and
stopPropagation has not been called, the event triggers the
appropriate EventListeners on the target itself.
For event bubbling:
Any event handler may choose to prevent further event propagation by
calling the stopPropagation method of the Event interface. If any
EventListener calls this method, all additional EventListeners on the
current EventTarget will be triggered but bubbling will cease at that
level. Only one call to stopPropagation is required to prevent further
bubbling.
For event cancelation:
Cancelation is accomplished by calling the Event's preventDefault
method. If one or more EventListeners call preventDefault during
any phase of event flow the default action will be canceled.
Examples
In the following examples, a click on the hyperlink in the web browser triggers the event's flow (the event listeners are executed) and the event target's default action (a new tab is opened).
HTML:
<div id="a">
<a id="b" href="http://www.google.com/" target="_blank">Google</a>
</div>
<p id="c"></p>
JavaScript:
var el = document.getElementById("c");
function capturingOnClick1(ev) {
el.innerHTML += "DIV event capture<br>";
}
function capturingOnClick2(ev) {
el.innerHTML += "A event capture<br>";
}
function bubblingOnClick1(ev) {
el.innerHTML += "DIV event bubbling<br>";
}
function bubblingOnClick2(ev) {
el.innerHTML += "A event bubbling<br>";
}
// The 3rd parameter useCapture makes the event listener capturing (false by default)
document.getElementById("a").addEventListener("click", capturingOnClick1, true);
document.getElementById("b").addEventListener("click", capturingOnClick2, true);
document.getElementById("a").addEventListener("click", bubblingOnClick1, false);
document.getElementById("b").addEventListener("click", bubblingOnClick2, false);
Example 1: it results in the output
DIV event capture
A event capture
A event bubbling
DIV event bubbling
Example 2: adding stopPropagation() to the function
function capturingOnClick1(ev) {
el.innerHTML += "DIV event capture<br>";
ev.stopPropagation();
}
results in the output
DIV event capture
The event listener prevented further downward and upward propagation of the event. However it did not prevent the default action (a new tab opening).
Example 3: adding stopPropagation() to the function
function capturingOnClick2(ev) {
el.innerHTML += "A event capture<br>";
ev.stopPropagation();
}
or the function
function bubblingOnClick2(ev) {
el.innerHTML += "A event bubbling<br>";
ev.stopPropagation();
}
results in the output
DIV event capture
A event capture
A event bubbling
This is because both event listeners are registered on the same event target. The event listeners prevented further upward propagation of the event. However they did not prevent the default action (a new tab opening).
Example 4: adding preventDefault() to any function, for instance
function capturingOnClick1(ev) {
el.innerHTML += "DIV event capture<br>";
ev.preventDefault();
}
prevents a new tab from opening.

return false;
return false; does 3 separate things when you call it:
event.preventDefault() – It stops the browsers default behaviour.
event.stopPropagation() – It prevents the event from propagating (or “bubbling up”) the DOM.
Stops callback execution and returns immediately when called.
Note that this behaviour differs from normal (non-jQuery) event handlers, in which, notably, return false does not stop the event from bubbling up.
preventDefault();
preventDefault(); does one thing: It stops the browsers default behaviour.
When to use them?
We know what they do but when to use them? Simply it depends on what you want to accomplish. Use preventDefault(); if you want to “just” prevent the default browser behaviour. Use return false; when you want to prevent the default browser behaviour and prevent the event from propagating the DOM. In most situations where you would use return false; what you really want is preventDefault().
Examples:
Let’s try to understand with examples:
We will see pure JAVASCRIPT example
Example 1:
<div onclick='executeParent()'>
<a href='https://stackoverflow.com' onclick='executeChild()'>Click here to visit stackoverflow.com</a>
</div>
<script>
function executeChild() {
alert('Link Clicked');
}
function executeParent() {
alert('div Clicked');
}
</script>
Run the above code you will see the hyperlink ‘Click here to visit
stackoverflow.com‘ now if you click on that link first you will get
the javascript alert Link Clicked Next you will get the javascript
alert div Clicked and immediately you will be redirected to
stackoverflow.com.
Example 2:
<div onclick='executeParent()'>
<a href='https://stackoverflow.com' onclick='executeChild()'>Click here to visit stackoverflow.com</a>
</div>
<script>
function executeChild() {
event.preventDefault();
event.currentTarget.innerHTML = 'Click event prevented'
alert('Link Clicked');
}
function executeParent() {
alert('div Clicked');
}
</script>
Run the above code you will see the hyperlink ‘Click here to visit
stackoverflow.com‘ now if you click on that link first you will get
the javascript alert Link Clicked Next you will get the javascript
alert div Clicked Next you will see the hyperlink ‘Click here to
visit stackoverflow.com‘ replaced by the text ‘Click event prevented‘
and you will not be redirected to stackoverflow.com. This is due > to event.preventDefault() method we used to prevent the default click
action to be triggered.
Example 3:
<div onclick='executeParent()'>
<a href='https://stackoverflow.com' onclick='executeChild()'>Click here to visit stackoverflow.com</a>
</div>
<script>
function executeChild() {
event.stopPropagation();
event.currentTarget.innerHTML = 'Click event prevented'
alert('Link Clicked');
}
function executeParent() {
alert('div Clicked');
}
</script>
This time if you click on Link the function executeParent() will not
be called and you will not get the javascript alert div Clicked
this time. This is due to us having prevented the propagation to the
parent div using event.stopPropagation() method. Next you will see the
hyperlink ‘Click here to visit stackoverflow.com‘ replaced by the text
‘Click event is going to be executed‘ and immediately you will be
redirected to stackoverflow.com. This is because we haven’t prevented
the default click action from triggering this time using
event.preventDefault() method.
Example 4:
<div onclick='executeParent()'>
<a href='https://stackoverflow.com' onclick='executeChild()'>Click here to visit stackoverflow.com</a>
</div>
<script>
function executeChild() {
event.preventDefault();
event.stopPropagation();
event.currentTarget.innerHTML = 'Click event prevented'
alert('Link Clicked');
}
function executeParent() {
alert('Div Clicked');
}
</script>
If you click on the Link, the function executeParent() will not be
called and you will not get the javascript alert. This is due to us
having prevented the propagation to the parent div using
event.stopPropagation() method. Next you will see the hyperlink ‘Click
here to visit stackoverflow.com‘ replaced by the text ‘Click event
prevented‘ and you will not be redirected to stackoverflow.com. This
is because we have prevented the default click action from triggering
this time using event.preventDefault() method.
Example 5:
For return false I have three examples and all appear to be doing the exact same thing (just returning false), but in reality the
results are quite different. Here's what actually happens in each of
the above.
cases:
Returning false from an inline event handler prevents the browser from navigating to the link address, but it doesn't stop the event from propagating through the DOM.
Returning false from a jQuery event handler prevents the browser from navigating to the link address and it stops the event from propagating through the DOM.
Returning false from a regular DOM event handler does absolutely nothing.
Will see all three example.
Inline return false.
<div onclick='executeParent()'>
<a href='https://stackoverflow.com' onclick='return false'>Click here to visit stackoverflow.com</a>
</div>
<script>
var link = document.querySelector('a');
link.addEventListener('click', function() {
event.currentTarget.innerHTML = 'Click event prevented using inline html'
alert('Link Clicked');
});
function executeParent() {
alert('Div Clicked');
}
</script>
Returning false from a jQuery event handler.
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<div>
<a href='https://stackoverflow.com'>Click here to visit stackoverflow.com</a>
</div>
<script>
$('a').click(function(event) {
alert('Link Clicked');
$('a').text('Click event prevented using return FALSE');
$('a').contents().unwrap();
return false;
});
$('div').click(function(event) {
alert('Div clicked');
});
</script>
Returning false from a regular DOM event handler.
<div onclick='executeParent()'>
<a href='https://stackoverflow.com' onclick='executeChild()'>Click here to visit stackoverflow.com</a>
</div>
<script>
function executeChild() {
event.currentTarget.innerHTML = 'Click event prevented'
alert('Link Clicked');
return false
}
function executeParent() {
alert('Div Clicked');
}
</script>
Hope these examples are clear. Try executing all these examples in a html file to see how they work.

This is the quote from here
Event.preventDefault
The preventDefault method prevents an event from carrying out its default functionality. For example, you would use preventDefault on an A element to stop clicking that element from leaving the current page:
//clicking the link will *not* allow the user to leave the page
myChildElement.onclick = function(e) {
e.preventDefault();
console.log('brick me!');
};
//clicking the parent node will run the following console statement because event propagation occurs
logo.parentNode.onclick = function(e) {
console.log('you bricked my child!');
};
While the element's default functionality is bricked, the event continues to bubble up the DOM.
Event.stopPropagation
The second method, stopPropagation, allows the event's default functionality to happen but prevents the event from propagating:
//clicking the element will allow the default action to occur but propagation will be stopped...
myChildElement.onclick = function(e) {
e.stopPropagation();
console.log('prop stop! no bubbles!');
};
//since propagation was stopped by the child element's onClick, this message will never be seen!
myChildElement.parentNode.onclick = function(e) {
console.log('you will never see this message!');
};
stopPropagation effectively stops parent elements from knowing about a given event on its child.
While a simple stop method allows us to quickly handle events, it's
important to think about what exactly you want to happen with
bubbling. I'd bet that all a developer really wants is preventDefault
90% of the time! Incorrectly "stopping" an event could cause you
numerous troubles down the line; your plugins may not work and your
third party plugins could be bricked. Or worse yet -- your code
breaks other functionality on a site.

event.preventDefault()
Prevents the browsers default behaviour (such as opening a link), but does not stop the event from bubbling up the DOM.
event.stopPropagation()Prevents the event from bubbling up the DOM, but does not stop the browsers default behaviour.
return false;Usually seen in jQuery code, it Prevents the browsers default behaviour, Prevents the event from bubbling up the
DOM, and immediately Returns from any callback.
Check out this really nice & easy 4 min read with examples from where the above piece was taken.

event.preventDefault(); Stops the default action of an element from happening.
event.stopPropagation(); Prevents the event from bubbling up the DOM tree, preventing any parent handlers from being notified of the event.
For example, if there is a link with a click method attached inside of a DIV or FORM that also has a click method attached, it will prevent the DIV or FORM click method from firing.

Event.preventDefault- stops browser default behaviour. Now comes what is browser default behaviour. Assume you have a anchor tag and it has got a href attribute and this anchor tag is nested inside a div tag which has got a click event. Default behaviour of anchor tag is when clicked on the anchor tag it should navigate, but what event.preventDefault does is it stops the navigation in this case. But it never stops the bubbling of event or escalation of event i.e
<div class="container">
Click Me!
</div>
$('.container').on('click', function(e) {
console.log('container was clicked');
});
$('.element').on('click', function(e) {
e.preventDefault(); // Now link won't go anywhere
console.log('element was clicked');
});
The result will be
"element was clicked"
"container was clicked"
Now event.StopPropation it stops bubbling of event or escalation of event. Now with above example
$('.container').on('click', function(e) {
console.log('container was clicked');
});
$('.element').on('click', function(e) {
e.preventDefault(); // Now link won't go anywhere
e.stopPropagation(); // Now the event won't bubble up
console.log('element was clicked');
});
Result will be
"element was clicked"
For more info refer this link
https://codeplanet.io/preventdefault-vs-stoppropagation-vs-stopimmediatepropagation/

$("#but").click(function(event){
console.log("hello");
event.preventDefault();
});
$("#foo").click(function(){
alert("parent click event fired !");
});
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<div id="foo">
<button id="but">button</button>
</div>

Related

Activating an element's listener inside a div without activating the div's listener

I want to be able to activate an element's listener without activating the listener of the div that contains my element.
$('body').on('click', '.thiscoll', function(){
if (type === "form") {
hidePanels();
$('#navbar-pannel').show();
}
});
$('#main_container').on('click', 'a', function(){
hidePanels();
$('#custom-nav').show();
$('#l-name').html("New link name");
$('#l-destination').html("New link destination");
});
The first listener is on my div, while the second listener is on my links that are contained into my div. When I click on a link, it first triggers the 'a' listener, then the '.thiscoll' listener, while I only want to trigger the 'a' listener.
Is it possible?
Thanks.
Long story short, you want to stop event propagation. Something like
$('a').on('click', function(event) {
event.stopPropagation();
// and possibly do something else you require
});
should do.
Yes, what you want is possible. With events in Javascript we have this nice thing called event capturing and event bubbling. By default, browsers will register events in the bubbling phase.
For you, this means that the target you click will have its event handlers fired first. Then its parent's. Then its parent's parent's and so on. You can read more about it on MDN
To stop this propagation, you can use the stopPropagtion method on the Event-object. The Event object is supplied as the first argument in your event listener:
const main = document.querySelector('.main');
const button = document.querySelector('.button');
const stopPropagation = document.getElementById('stopPropagation');
main.addEventListener('click', () => console.log('Clicked on main'));
button.addEventListener('click', (evt) => {
if (stopPropagation.checked) {
evt.stopPropagation();
}
console.log('clicked button');
});
<input id="stopPropagation" type="checkbox">
<label for="stopPropagation">stopPropagation</label>
<div class="main">
Hello, World
<button class="button">Button</button>
</div>

jQuery 'on()' command

So, i wondered, why this code doesn't work properly, and what can i do, to prevent such a behaviour:
If I would need to prevent event propagation of parent, whilst particular child got clicked, i used method 1, but it seems not to be working, but method 2 is working fine though.
//method 1
$(document).on({
click: function(e) {
console.log('clicked!');
e.preventDefault();
return false;
}
}, '.hax');
//method 2
/*$('.hax').on('click', function(e){
e.preventDefault();
return false;
});*/
//uncommenting will prevent event propagation
.hax {
background-color: whitesmoke;
cursor: pointer;
}
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<div class='wrapper' onclick='alert("hello")'>
<div class='hax'>hax!</div>
</div>
Method 1 Is using event delegation ,so in it event is not directly bind with the element , its bound with the parent ,So in your case the parent is document . in this the case whatever event will be fired for that particular element it will be tracked down from the DOM tree and will execute the parent call before. In your case it will first call the alert from parent .
In method 2 - event is directly bound with the element , The event of parent will still got fired unless you prevent that in the handler but since the handler is bound to the target , you will not face any other action(alert in your case)
Get better Idea of
Event Delegation
You are creating an event delegation by method 1, which can be created the following way too:
$(document).on('click', '.hax', function (e) {
console.log('clicked!');
e.preventDefault();
return false;
});
For clarifying event delegation briefly:
Understanding how events propagate is an important factor in being able to leverage Event Delegation. Any time one of our anchor tags is clicked, a click event is fired for that anchor, and then bubbles up the DOM tree(Up to DOM top), triggering each of its parent click event handlers.
It does not mean you can't achieve your goal here with this method, but in order to make it work, you can create a middle parent for div.hax which is descendant of div.wrapper. I mean:
<div class='wrapper' onclick='alert("hello")'>
<div id="stopHere">
<div class='hax'>hax!</div>
</div>
</div>
Now, we can use method 1, but we only need to stop event propagation / event delegation before it reach div.wrapper. Thus in our newly added div#stopHere:
$("div#stopHere").on('click', '.hax', function (e) {
console.log('clicked!');
e.preventDefault();
return false;
});

jquery: event.stopImmediatePropagation() vs return false

Is there any difference between calling event.stopImmediatePropagation() and return false inside an event handler ?
Yes they are different.
return false is basically the same as calling both, event.stopPropagation() and event.preventDefault().
Whereas event.stopImmediatePropagation() is the same as event.stopPropagation() plus preventing other registered event handlers on the same element to be executed. So it does not prevent the default action for an event, such as following a clicked link.
In short:
stop | prevent | prevent "same element"
bubbling | default action | event handlers
return false Yes Yes No
preventDefault No Yes No
stopPropagation Yes No No
stopImmediatePropagation Yes No Yes
return false also works in "normal" JavaScript event handlers
event.stopPropagation() and event.preventDefault() also work in "normal" JavaScript event handlers (in a W3C compatible browser), whereas event.stopImmediatePropagation() is an extension from jQuery (update: apparently it is part of the DOM Level 3 Events specification).
Note: return false does not prevent the event from bubbling up in "normal" (non-jQuery) event handlers (see this answer)(but still prevents the default action).
Maybe worth reading:
jQuery Events: Stop (Mis)Using Return False
quirksmode.org - Event order
Returning false will stop event bubbling, but other bound events will fire. However stopImmediatePropagation prevents other bound events from firing and stops bubbling.
Code Example of this on jsfiddle.
Here is the complete demo for return false, preventDefault, stopPropagation and stopImmediatePropagation:
var kid = document.getElementsByTagName('button')[0];
var dad = document.getElementsByTagName('div')[0];
kid.addEventListener('click', function(e) {
console.log('kid here');
e.stopImmediatePropagation();
});
kid.addEventListener('click', function(e) {
console.log('neighbour kid here');
});
dad.addEventListener('click', function(e) {
console.log('dad here');
});
dad.addEventListener('click', function(e) {
console.log('neighbour dad here');
});
<div>
<button>press</button>
</div>
(Also available on JSFiddle.)
The table in manwal’s answer is not fully correct.
stop | prevent | prevent
bubbling | default action | event handlers
| | Same Element | Parent Element
return false Yes Yes No No
preventDefault No Yes No No
stopPropagation Yes No No Yes
stopImmediatePropagation Yes No Yes **Yes**
Yes. event.stopImmediatePropagation() won't let any other handlers for that event be called, regardless of where they are bound. Return false only stops handlers bound to other elements (ie not the same element as the event handler dealing with the stopImmediatePropagation() call) from receiving the event.
#FelixKling answer's table having great concept:
I am posting more explained table:
stop | prevent | prevent |
bubbling | default action | event handlers |
Same Element | Parent Element
return false Yes Yes No No
preventDefault No Yes No No
stopPropagation Yes No No Yes
stopImmediatePropagation Yes No Yes No
Reference: https://stackoverflow.com/a/5302939/2236219

How to stop event bubbling with jquery live?

I am trying to stop some events but stopPropagation does not work with "live" so I am not sure what to do. I found this on their site.
Live events do not bubble in the
traditional manner and cannot be
stopped using stopPropagation or
stopImmediatePropagation. For example,
take the case of two click events -
one bound to "li" and another "li a".
Should a click occur on the inner
anchor BOTH events will be triggered.
This is because when a
$("li").bind("click", fn); is bound
you're actually saying "Whenever a
click event occurs on an LI element -
or inside an LI element - trigger this
click event." To stop further
processing for a live event, fn must
return false
It says that fn must return false so what I tried to do
$('.MoreAppointments').live('click', function(e) {
alert("Hi");
return false;
});
but that did not work so I am not sure how to make it return false.
Update
Here is some more information.
I have a table cell and I bind a click event to it.
$('#CalendarBody .DateBox').click(function(e)
{
AddApointment(this);
});
So the AddApointment just makes some ui dialog box.
Now the live code(MoreAppointments) sits in this table cell and is basically an anchor tag. So when I click on the anchor tag it first goes to the above code(addApointment - so runs that event first) runs that but does not launch my dialog box instead it goes straight to the (MoreAppointment) event and runs that code. Once that code has run it launches the dialog box from "addApointment".
Update 2
Here is some of the html. I did not copy the whole table since it is kinda big and all the cells repeat itself with the same data. If needed I will post it.
<td id="c_12012009" class="DateBox">
<div class="DateLabel">
1</div>
<div class="appointmentContainer">
<a class="appointments">Fkafkafk fakfka kf414<br />
</a><a class="appointments">Fkafkafk fakfka kf414<br />
</a><a class="appointments">Fkafkafk fakfka kf414<br />
</a><a class="appointments">Fkafkafk fakfka kf414<br />
</a><a class="appointments">Fkafkafk fakfka kf414<br />
</a>
</div>
<div class="appointmentOverflowContainer">
<div>
<a class="MoreAppointments">+1 More</a></div>
</div>
</td>
The short answer is simply, you can't.
The problem
Normally, you can stop an event from "bubbling up" to event handlers on outer elements because the handlers for inner elements are called first. However, jQuery's "live events" work by attaching a proxy handler for the desired event to the document element, and then calling the appropriate user-defined handler(s) after the event bubbles up the document.
(source: shog9.com)
This generally makes "live" binding a rather efficient means of binding events, but it has two big side-effects: first, any event handler attached to an inner element can prevent "live" events from firing for itself or any of its children; second, a "live" event handler cannot prevent any event handlers attached directly to children of the document from firing. You can stop further processing, but you can't do anything about processing that has already occurred... And by the time your live event fires, the handler attached directly to the child has already been called.
Solution
Your best option here (so far as I can tell from what you've posted) is to use live binding for both click handlers. Once that's done, you should be able to return false from the .MoreAppointments handler to prevent the .DateBox handler from being called.
Example:
$('.MoreAppointments').live('click', function(e)
{
alert("Hi");
return false; // prevent additional live handlers from firing
});
// use live binding to allow the above handler to preempt
$('#CalendarBody .DateBox').live('click', function(e)
{
AddApointment(this);
});
I've used such kind if code and it worked for me:
$('#some-link').live('click', function(e) {
alert("Link clicked 1");
e.stopImmediatePropagation();
});
$('#some-link').live('click', function(e) {
alert("Link clicked 2");
});
so, it seems to me, that now JQuery support stopImmediatePropagation with live events
Maybe you could check that the click event didn't occur on an a element:
$('#CalendarBody .DateBox').click(function(e) {
// if the event target is an <a> don't process:
if ($(e.target).is('a')) return;
AddApointment(this);
});
Might Work?
I'm using this:
if(event.target != this)return; // stop event bubbling for "live" event
I use
e.stopPropagation(); // to prevent event from bubbling up
e.preventDefault(); // then cancel the event (if it's cancelable)
I've used this in certain situations. Note: not always applicable, so assess for your needs as always:
html:
Click me
js (in your live event handler):
if(e.target.className == 'my-class-name') {
e.preventDefault();
// do something you want to do...
}
This way, my live event only 'runs' when a particular element type/classname attr is clicked.
The e.preventDefault() here is to stop the link I'm clicking moving the scroll-position to the top of the page.
Simply use **"on"** function to bind click event of child as well as parent element.
Example : $("#content-container").on("click","a.childElement",function(e){
alert("child clicked");
e.stopPropagation() ;
});
$("#content-container").on("click","div.parentElement",function(e){
alert("parent clicked");
});
( where content-container is the outer div containing both parent as well as child elements. )
Here only "child clicked" alert will occur.
Thanks.

disable all click events on page (javascript)

Whats the easiest way to temporarily disable all mouse click/drag etc events through javascript?
I thought I could do document.onclick = function() { return false; }; ...etc, but that's not working.
If the objective is to disable click on the whole page then you can do something like this
document.addEventListener("click", handler, true);
function handler(e) {
e.stopPropagation();
e.preventDefault();
}
true argument in addEventListener would ensure that the handler is executed on the event capturing phase i.e a click on any element would first be captured on the document and the listener for document's click event would be executed first before listener for any other element. The trick here is to stop the event from further propagation to the elements below thus ending the dispatch process to make sure that the event doesn't reach the target.
Also you need to stop default behavior associated with event target elements explicitly as they would be executed by default after the dispatch process has finished even if the event was stopped propagating further from above
It can be further modified to use selectively.
function handler(e) {
if(e.target.className=="class_name"){
e.stopPropagation();
e.preventDefault();
}
}
handler modified this way would disable clicks only on elements with class "class_name".
function handler(e) {
if(e.target.className!=="class_name") {
e.stopPropagation()
}
}
this would enable clicks only on elements with class "class_name".
Hope this helped :)
Dynamically disable all clicks on page
let freezeClic = false; // just modify that variable to disable all clics events
document.addEventListener("click", e => {
if (freezeClic) {
e.stopPropagation();
e.preventDefault();
}
}, true);
I often use it while loading or to avoid user to accidentally clic twice on an action button. Simple and performance friendly :)
Please check this working example
Alternative CSS way
Another one that I really like because of the visual feedback the user have:
/* style.css */
.loading {
cursor: wait; /* busy cursor feedback */
}
.loading * {
/* disable all mouse events on children elements */
pointer-events: none;
}
A simple example to dynamically add the .loading class:
const elm = document.getElementById('myElm')
elm.classList.add('loading')
myAsyncFunction().then(() => elm.classList.remove('loading'))
If you want absolutely nothing draggable/clickable, disabling typing in input fields etc, I'd consider showing a absolutely positioned transparent div over the entire page, so that every click will be on the div, which will do nothing. That will grant you swift and neat switching on and off of this click-disabler, without having to register heaps of listeners
The winning answer works well, but if you had pass the capture true boolean value, at the moment you want to remove the listener, you have to pass the exact same value. Otherwise, the listener removal will not work.
Example:
listener addition
document.addEventListener('click', DisableClickOnPage.handler, true);
listener removal
document.removeEventListener('click', DisableClickOnPage.handler, true);
Doc: https://developer.mozilla.org/en-US/docs/Web/API/EventTarget/removeEventListener
window.addEventListener("click", (e) => {
e.stopPropagation();
e.stopImmediatePropagation();
e.preventDefault();
}, true)
If we added a listener to document instead of window anyone can add a listener to window and it works. Because of document child of window and its events trigger always after window events.
We use 3 method of Event object.
stopPropagation for prevent all capturing and bubbling
stopImmediatePropagation for prevent same listeners (e.g. another window click listeners)
preventDefault for prevent all user agent event (e.g anchor href or form submit)
If onclick = null has been executed how to revoke the onclick event to normal functioning.. or
Link text
<script type="text/javascript">
function yourFunction(anchor)
{ if(anchor.disabled) return;
/* Your function here */
}
</script>
This article would probably be useful:
http://www.computerhowtoguy.com/how-to-use-the-jquery-unbind-method-on-all-child-elements/
One part in particular is a recursive function that removes all click events. Remember that jQuery will remove click events IF the click event was created using jQuery. the function given in the article will remove both those created with jQuery and those that were not. The function given is this:
function RecursiveUnbind($jElement) {
// remove this element's and all of its children's click events
$jElement.unbind();
$jElement.removeAttr('onclick');
$jElement.children().each(function () {
RecursiveUnbind($(this));
});
}
You would call the function like this:
RecursiveUnbind($('#container'));
That function takes a jQuery object parameter, but you could easily change it up to pass a string as the name of the ID for the element, or however you think is best.
To prevent the default behavior of an event, use event.stopPropagation() and event.preventDefault() in your event handler. And don't forget, return false; is another method for indicating that you want to cancel the default action...
The Event property returnValue indicates whether the default action for this event has been prevented or not. It is set to true by default, allowing the default action to occur. Setting this property to false prevents the default action. (Source: MDN Web Docs: Event.returnValue.)
Typically, we return a value from any function when it has any meaningful or useful purpose -- return false to cancel an event is meaningful because it indicates a failed event, and it's useful because the event-handler uses it.
For greatest cross-browser compatibility, remember to return false;...
document.addEventListener("click",handler,true);
function handler(e){
e.stopPropagation();
e.preventDefault();
return false;
}

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