Why alert() executes even though preventDefault() is called before alert()? - javascript

In the following code, why the alert('Alert on btn is triggered') }) fires, even though event.preventDefault() is called before this line in the click handler of the #btn el.
Also, why onclick="alerted() does not fires on #btn or on #wrap div but the callback fires attached to click with addEventListener fires.
var btn = document.getElementById('btn')
var wrap = document.getElementById('wrap')
btn.addEventListener('click', function() {
event.stopPropagation()
if (event.cancelable) {
event.preventDefault()
}
alert('Alert on btn is triggered')
})
function alerted() {
alert('Alerted fired')
}
wrap.addEventListener('click', function() {
alert(this.id)
alert(event.target.tagName + "#" + event.target.id)
})
#wrap {
padding: 20px;
border: 1px solid red;
}
<div id="wrap" onclick="alerted">
<button id="btn" onclick="alerted">Click Me</button>
</div>

Calling event.preventDefault() or event.stopPropagation will not stop the callback currently in progress. No matter the context of a function, if it starts running, the only way to stop it from continuing is to explicitly return.
If you want to make sure the rest of the function stops running when preventDefault() is called, change to:
if (event.cancelable) {
event.preventDefault();
return;
}
It would also probably be a good idea to define event as the argument that the handler takes, rather than relying on the implicitly global window.event (which, although it works in some browsers, is not a great idea to use).
var btn = document.getElementById('btn')
var wrap = document.getElementById('wrap')
btn.addEventListener('click', function(event) {
event.stopPropagation()
if (event.cancelable) {
event.preventDefault();
return;
}
alert('Alert on btn is triggered')
})
function alerted() {
alert('Alerted fired')
}
wrap.addEventListener('click', function() {
alert(this.id)
alert(event.target.tagName + "#" + event.target.id)
})
#wrap {
padding: 20px;
border: 1px solid red;
}
<div id="wrap" onclick="alerted">
<button id="btn" onclick="alerted">Click Me</button>
</div>

Explanation: the alert is not default in your click event, calling event.preventDefault(); or not will will trigger the alert anyway.
preventDefault() depends on the default event. Example: using preventDefault() on click event will prevent clicking trigger or using preventDefault() on keydown will prevent the default keyboard pressing down event.
Just like the current answer, to prevent the alert, use return;
Also, I just noticed, your code onclick="alerted" should be onclick="alerted()"
UPDATE:
Explanation 1: The alert won't fire in the btn because it was prevented. you put alerted() on onclick and the click event was prevented.
In other words, alert is inside click, click was prevented so the alert will not fire.
Explanation 2: Button is an object not an event, objects can have the same events. Example: divs are container but you can use click event on them.

Because when the event fires even if you stop his propagation it will not fire in other event listeners but your function will continue to execute.

Related

.toggle() bug toggling multiple elements [duplicate]

I'm currently using jQuery to make a div clickable and in this div I also have anchors. The problem I'm running into is that when I click on an anchor both click events are firing (for the div and the anchor). How do I prevent the div's onclick event from firing when an anchor is clicked?
Here's the broken code:
JavaScript
var url = $("#clickable a").attr("href");
$("#clickable").click(function() {
window.location = url;
return true;
})
HTML
<div id="clickable">
<!-- Other content. -->
I don't want #clickable to handle this click event.
</div>
Events bubble to the highest point in the DOM at which a click event has been attached. So in your example, even if you didn't have any other explicitly clickable elements in the div, every child element of the div would bubble their click event up the DOM to until the DIV's click event handler catches it.
There are two solutions to this is to check to see who actually originated the event. jQuery passes an eventargs object along with the event:
$("#clickable").click(function(e) {
var senderElement = e.target;
// Check if sender is the <div> element e.g.
// if($(e.target).is("div")) {
window.location = url;
return true;
});
You can also attach a click event handler to your links which tell them to stop event bubbling after their own handler executes:
$("#clickable a").click(function(e) {
// Do something
e.stopPropagation();
});
Use stopPropagation method, see an example:
$("#clickable a").click(function(e) {
e.stopPropagation();
});
As said by jQuery Docs:
stopPropagation method prevents the event from bubbling up the DOM
tree, preventing any parent handlers from being notified of the event.
Keep in mind that it does not prevent others listeners to handle this event(ex. more than one click handler for a button), if it is not the desired effect, you must use stopImmediatePropagation instead.
Here my solution for everyone out there looking for a non-jQuery code (pure javascript)
document.getElementById("clickable").addEventListener("click", function(e) {
e = window.event || e;
if(this === e.target) {
// put your code here
}
});
Your code wont be executed if clicked on parent's children
If you do not intend to interact with the inner element/s in any case, then a CSS solution might be useful for you.
Just set the inner element/s to pointer-events: none
in your case:
.clickable > a {
pointer-events: none;
}
or to target all inner elements generally:
.clickable * {
pointer-events: none;
}
This easy hack saved me a lot of time while developing with ReactJS
Browser support could be found here: http://caniuse.com/#feat=pointer-events
Inline Alternative:
<div>
<!-- Other content. -->
<a onclick='event.stopPropagation();' href="http://foo.example">I don't want #clickable to handle this click event.</a>
</div>
You can also try this
$("#clickable").click(function(event) {
var senderElementName = event.target.tagName.toLowerCase();
if(senderElementName === 'div') {
// Do something here
} else {
// Do something with <a> tag
}
});
Writing if anyone needs (worked for me):
event.stopImmediatePropagation()
From this solution.
Using return false; or e.stopPropogation(); will not allow further code to execute. It will stop flow at this point itself.
If you have multiple elements in the clickable div, you should do this:
$('#clickable *').click(function(e){ e.stopPropagation(); });
I compare to ev.currentTarget when this is not available (React, etc).
$("#clickable").click(function(e) {
if (e.target === e.currentTarget) {
window.location = url;
return true;
}
})
Here's an example using Angular 2+
For example, if you wanted to close a Modal Component if the user clicks outside of it:
// Close the modal if the document is clicked.
#HostListener('document:click', ['$event'])
public onDocumentClick(event: MouseEvent): void {
this.closeModal();
}
// Don't close the modal if the modal itself is clicked.
#HostListener('click', ['$event'])
public onClick(event: MouseEvent): void {
event.stopPropagation();
}
If it is in inline context, in HTML try this:
onclick="functionCall();event.stopPropagation();
e.stopPropagation() is a correct solution, but in case you don't want to attach any event handler to your inner anchor, you can simply attach this handler to your outer div:
e => { e.target === e.currentTarget && window.location = URL; }
var inner = document.querySelector("#inner");
var outer = document.querySelector("#outer");
inner.addEventListener('click',innerFunction);
outer.addEventListener('click',outerFunction);
function innerFunction(event){
event.stopPropagation();
console.log("Inner Functiuon");
}
function outerFunction(event){
console.log("Outer Functiuon");
}
<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<meta name="viewport" content="width=device-width">
<title>Pramod Kharade-Event with Outer and Inner Progration</title>
</head>
<body>
<div id="outer" style="width:100px;height:100px;background-color:green;">
<div id="inner" style="width:35px;height:35px;background-color:yellow;"></div>
</div>
</body>
</html>
You need to stop the event from reaching (bubbling to) the parent (the div).
See the part about bubbling here, and jQuery-specific API info here.
To specify some sub element as unclickable write the css hierarchy as in the example below.
In this example I stop propagation to any elements (*) inside td inside tr inside a table with the class ".subtable"
$(document).ready(function()
{
$(".subtable tr td *").click(function (event)
{
event.stopPropagation();
});
});
You can check whether the target is not your div-element and then issue another click event on the parent after which you will "return" from the handle.
$('clickable').click(function (event) {
let div = $(event.target);
if (! div.is('div')) {
div.parent().click();
return;
}
// Then Implement your logic here
}
Here is a non jQuery solution that worked for me.
<div style="background:cyan; width:100px; height:100px;" onclick="if (event.srcElement==this) {console.log('outer');}">
<a style="background:red" onclick="console.log('inner');">Click me</a>
</div>
for those that are not using jQuery
document.querySelector('.clickable').addEventListener('click', (e) =>{
if(!e.target.classList.contains('clickable')) return
// place code here
})
In case someone had this issue using React, this is how I solved it.
scss:
#loginBackdrop {
position: absolute;
width: 100% !important;
height: 100% !important;
top:0px;
left:0px;
z-index: 9; }
#loginFrame {
width: $iFrameWidth;
height: $iFrameHeight;
background-color: $mainColor;
position: fixed;
z-index: 10;
top: 50%;
left: 50%;
margin-top: calc(-1 * #{$iFrameHeight} / 2);
margin-left: calc(-1 * #{$iFrameWidth} / 2);
border: solid 1px grey;
border-radius: 20px;
box-shadow: 0px 0px 90px #545454; }
Component's render():
render() {
...
return (
<div id='loginBackdrop' onClick={this.props.closeLogin}>
<div id='loginFrame' onClick={(e)=>{e.preventDefault();e.stopPropagation()}}>
... [modal content] ...
</div>
</div>
)
}
By a adding an onClick function for the child modal (content div) mouse click events are prevented to reach the 'closeLogin' function of the parent element.
This did the trick for me and I was able to create a modal effect with 2 simple divs.
If a child element is clicked, then the event bubbles up to the parent and event.target !== event.currentTarget.
So in your function, you can check this and return early, i.e.:
var url = $("#clickable a").attr("href");
$("#clickable").click(function(event) {
if ( event.target !== event.currentTarget ){
// user clicked on a child and we ignore that
return;
}
window.location = url;
return true;
})
This is what you are looking for
mousedown event. this works on every DOM elements to prevent javascript focus handler like this:
$('.no-focus').mousedown(function (e) {
e.prevenDefault()
// do stuff
}
in vue.js framework, you can use modifier like this:
<span #mousedown.prevent> no focus </span>
Note that using on the input will prevent text selection handler
add a as follows:
....
or return false; from click handler for #clickable like:
$("#clickable").click(function() {
var url = $("#clickable a").attr("href");
window.location = url;
return false;
});
All solution are complicated and of jscript. Here is the simplest version:
var IsChildWindow=false;
function ParentClick()
{
if(IsChildWindow==true)
{
IsChildWindow==false;
return;
}
//do ur work here
}
function ChildClick()
{
IsChildWindow=true;
//Do ur work here
}
<a onclick="return false;" href="http://foo.example">I want to ignore my parent's onclick event.</a>

2 elements in same position with different functions and both are executed [duplicate]

I'm currently using jQuery to make a div clickable and in this div I also have anchors. The problem I'm running into is that when I click on an anchor both click events are firing (for the div and the anchor). How do I prevent the div's onclick event from firing when an anchor is clicked?
Here's the broken code:
JavaScript
var url = $("#clickable a").attr("href");
$("#clickable").click(function() {
window.location = url;
return true;
})
HTML
<div id="clickable">
<!-- Other content. -->
I don't want #clickable to handle this click event.
</div>
Events bubble to the highest point in the DOM at which a click event has been attached. So in your example, even if you didn't have any other explicitly clickable elements in the div, every child element of the div would bubble their click event up the DOM to until the DIV's click event handler catches it.
There are two solutions to this is to check to see who actually originated the event. jQuery passes an eventargs object along with the event:
$("#clickable").click(function(e) {
var senderElement = e.target;
// Check if sender is the <div> element e.g.
// if($(e.target).is("div")) {
window.location = url;
return true;
});
You can also attach a click event handler to your links which tell them to stop event bubbling after their own handler executes:
$("#clickable a").click(function(e) {
// Do something
e.stopPropagation();
});
Use stopPropagation method, see an example:
$("#clickable a").click(function(e) {
e.stopPropagation();
});
As said by jQuery Docs:
stopPropagation method prevents the event from bubbling up the DOM
tree, preventing any parent handlers from being notified of the event.
Keep in mind that it does not prevent others listeners to handle this event(ex. more than one click handler for a button), if it is not the desired effect, you must use stopImmediatePropagation instead.
Here my solution for everyone out there looking for a non-jQuery code (pure javascript)
document.getElementById("clickable").addEventListener("click", function(e) {
e = window.event || e;
if(this === e.target) {
// put your code here
}
});
Your code wont be executed if clicked on parent's children
If you do not intend to interact with the inner element/s in any case, then a CSS solution might be useful for you.
Just set the inner element/s to pointer-events: none
in your case:
.clickable > a {
pointer-events: none;
}
or to target all inner elements generally:
.clickable * {
pointer-events: none;
}
This easy hack saved me a lot of time while developing with ReactJS
Browser support could be found here: http://caniuse.com/#feat=pointer-events
Inline Alternative:
<div>
<!-- Other content. -->
<a onclick='event.stopPropagation();' href="http://foo.example">I don't want #clickable to handle this click event.</a>
</div>
You can also try this
$("#clickable").click(function(event) {
var senderElementName = event.target.tagName.toLowerCase();
if(senderElementName === 'div') {
// Do something here
} else {
// Do something with <a> tag
}
});
Writing if anyone needs (worked for me):
event.stopImmediatePropagation()
From this solution.
Using return false; or e.stopPropogation(); will not allow further code to execute. It will stop flow at this point itself.
If you have multiple elements in the clickable div, you should do this:
$('#clickable *').click(function(e){ e.stopPropagation(); });
I compare to ev.currentTarget when this is not available (React, etc).
$("#clickable").click(function(e) {
if (e.target === e.currentTarget) {
window.location = url;
return true;
}
})
Here's an example using Angular 2+
For example, if you wanted to close a Modal Component if the user clicks outside of it:
// Close the modal if the document is clicked.
#HostListener('document:click', ['$event'])
public onDocumentClick(event: MouseEvent): void {
this.closeModal();
}
// Don't close the modal if the modal itself is clicked.
#HostListener('click', ['$event'])
public onClick(event: MouseEvent): void {
event.stopPropagation();
}
If it is in inline context, in HTML try this:
onclick="functionCall();event.stopPropagation();
e.stopPropagation() is a correct solution, but in case you don't want to attach any event handler to your inner anchor, you can simply attach this handler to your outer div:
e => { e.target === e.currentTarget && window.location = URL; }
var inner = document.querySelector("#inner");
var outer = document.querySelector("#outer");
inner.addEventListener('click',innerFunction);
outer.addEventListener('click',outerFunction);
function innerFunction(event){
event.stopPropagation();
console.log("Inner Functiuon");
}
function outerFunction(event){
console.log("Outer Functiuon");
}
<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<meta name="viewport" content="width=device-width">
<title>Pramod Kharade-Event with Outer and Inner Progration</title>
</head>
<body>
<div id="outer" style="width:100px;height:100px;background-color:green;">
<div id="inner" style="width:35px;height:35px;background-color:yellow;"></div>
</div>
</body>
</html>
You need to stop the event from reaching (bubbling to) the parent (the div).
See the part about bubbling here, and jQuery-specific API info here.
To specify some sub element as unclickable write the css hierarchy as in the example below.
In this example I stop propagation to any elements (*) inside td inside tr inside a table with the class ".subtable"
$(document).ready(function()
{
$(".subtable tr td *").click(function (event)
{
event.stopPropagation();
});
});
You can check whether the target is not your div-element and then issue another click event on the parent after which you will "return" from the handle.
$('clickable').click(function (event) {
let div = $(event.target);
if (! div.is('div')) {
div.parent().click();
return;
}
// Then Implement your logic here
}
Here is a non jQuery solution that worked for me.
<div style="background:cyan; width:100px; height:100px;" onclick="if (event.srcElement==this) {console.log('outer');}">
<a style="background:red" onclick="console.log('inner');">Click me</a>
</div>
for those that are not using jQuery
document.querySelector('.clickable').addEventListener('click', (e) =>{
if(!e.target.classList.contains('clickable')) return
// place code here
})
In case someone had this issue using React, this is how I solved it.
scss:
#loginBackdrop {
position: absolute;
width: 100% !important;
height: 100% !important;
top:0px;
left:0px;
z-index: 9; }
#loginFrame {
width: $iFrameWidth;
height: $iFrameHeight;
background-color: $mainColor;
position: fixed;
z-index: 10;
top: 50%;
left: 50%;
margin-top: calc(-1 * #{$iFrameHeight} / 2);
margin-left: calc(-1 * #{$iFrameWidth} / 2);
border: solid 1px grey;
border-radius: 20px;
box-shadow: 0px 0px 90px #545454; }
Component's render():
render() {
...
return (
<div id='loginBackdrop' onClick={this.props.closeLogin}>
<div id='loginFrame' onClick={(e)=>{e.preventDefault();e.stopPropagation()}}>
... [modal content] ...
</div>
</div>
)
}
By a adding an onClick function for the child modal (content div) mouse click events are prevented to reach the 'closeLogin' function of the parent element.
This did the trick for me and I was able to create a modal effect with 2 simple divs.
If a child element is clicked, then the event bubbles up to the parent and event.target !== event.currentTarget.
So in your function, you can check this and return early, i.e.:
var url = $("#clickable a").attr("href");
$("#clickable").click(function(event) {
if ( event.target !== event.currentTarget ){
// user clicked on a child and we ignore that
return;
}
window.location = url;
return true;
})
This is what you are looking for
mousedown event. this works on every DOM elements to prevent javascript focus handler like this:
$('.no-focus').mousedown(function (e) {
e.prevenDefault()
// do stuff
}
in vue.js framework, you can use modifier like this:
<span #mousedown.prevent> no focus </span>
Note that using on the input will prevent text selection handler
add a as follows:
....
or return false; from click handler for #clickable like:
$("#clickable").click(function() {
var url = $("#clickable a").attr("href");
window.location = url;
return false;
});
All solution are complicated and of jscript. Here is the simplest version:
var IsChildWindow=false;
function ParentClick()
{
if(IsChildWindow==true)
{
IsChildWindow==false;
return;
}
//do ur work here
}
function ChildClick()
{
IsChildWindow=true;
//Do ur work here
}
<a onclick="return false;" href="http://foo.example">I want to ignore my parent's onclick event.</a>

How can I add a button with onclick event to a list item that already has an onclick event? [duplicate]

I'm currently using jQuery to make a div clickable and in this div I also have anchors. The problem I'm running into is that when I click on an anchor both click events are firing (for the div and the anchor). How do I prevent the div's onclick event from firing when an anchor is clicked?
Here's the broken code:
JavaScript
var url = $("#clickable a").attr("href");
$("#clickable").click(function() {
window.location = url;
return true;
})
HTML
<div id="clickable">
<!-- Other content. -->
I don't want #clickable to handle this click event.
</div>
Events bubble to the highest point in the DOM at which a click event has been attached. So in your example, even if you didn't have any other explicitly clickable elements in the div, every child element of the div would bubble their click event up the DOM to until the DIV's click event handler catches it.
There are two solutions to this is to check to see who actually originated the event. jQuery passes an eventargs object along with the event:
$("#clickable").click(function(e) {
var senderElement = e.target;
// Check if sender is the <div> element e.g.
// if($(e.target).is("div")) {
window.location = url;
return true;
});
You can also attach a click event handler to your links which tell them to stop event bubbling after their own handler executes:
$("#clickable a").click(function(e) {
// Do something
e.stopPropagation();
});
Use stopPropagation method, see an example:
$("#clickable a").click(function(e) {
e.stopPropagation();
});
As said by jQuery Docs:
stopPropagation method prevents the event from bubbling up the DOM
tree, preventing any parent handlers from being notified of the event.
Keep in mind that it does not prevent others listeners to handle this event(ex. more than one click handler for a button), if it is not the desired effect, you must use stopImmediatePropagation instead.
Here my solution for everyone out there looking for a non-jQuery code (pure javascript)
document.getElementById("clickable").addEventListener("click", function(e) {
e = window.event || e;
if(this === e.target) {
// put your code here
}
});
Your code wont be executed if clicked on parent's children
If you do not intend to interact with the inner element/s in any case, then a CSS solution might be useful for you.
Just set the inner element/s to pointer-events: none
in your case:
.clickable > a {
pointer-events: none;
}
or to target all inner elements generally:
.clickable * {
pointer-events: none;
}
This easy hack saved me a lot of time while developing with ReactJS
Browser support could be found here: http://caniuse.com/#feat=pointer-events
Inline Alternative:
<div>
<!-- Other content. -->
<a onclick='event.stopPropagation();' href="http://foo.example">I don't want #clickable to handle this click event.</a>
</div>
You can also try this
$("#clickable").click(function(event) {
var senderElementName = event.target.tagName.toLowerCase();
if(senderElementName === 'div') {
// Do something here
} else {
// Do something with <a> tag
}
});
Writing if anyone needs (worked for me):
event.stopImmediatePropagation()
From this solution.
Using return false; or e.stopPropogation(); will not allow further code to execute. It will stop flow at this point itself.
If you have multiple elements in the clickable div, you should do this:
$('#clickable *').click(function(e){ e.stopPropagation(); });
I compare to ev.currentTarget when this is not available (React, etc).
$("#clickable").click(function(e) {
if (e.target === e.currentTarget) {
window.location = url;
return true;
}
})
Here's an example using Angular 2+
For example, if you wanted to close a Modal Component if the user clicks outside of it:
// Close the modal if the document is clicked.
#HostListener('document:click', ['$event'])
public onDocumentClick(event: MouseEvent): void {
this.closeModal();
}
// Don't close the modal if the modal itself is clicked.
#HostListener('click', ['$event'])
public onClick(event: MouseEvent): void {
event.stopPropagation();
}
If it is in inline context, in HTML try this:
onclick="functionCall();event.stopPropagation();
e.stopPropagation() is a correct solution, but in case you don't want to attach any event handler to your inner anchor, you can simply attach this handler to your outer div:
e => { e.target === e.currentTarget && window.location = URL; }
var inner = document.querySelector("#inner");
var outer = document.querySelector("#outer");
inner.addEventListener('click',innerFunction);
outer.addEventListener('click',outerFunction);
function innerFunction(event){
event.stopPropagation();
console.log("Inner Functiuon");
}
function outerFunction(event){
console.log("Outer Functiuon");
}
<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<meta name="viewport" content="width=device-width">
<title>Pramod Kharade-Event with Outer and Inner Progration</title>
</head>
<body>
<div id="outer" style="width:100px;height:100px;background-color:green;">
<div id="inner" style="width:35px;height:35px;background-color:yellow;"></div>
</div>
</body>
</html>
You need to stop the event from reaching (bubbling to) the parent (the div).
See the part about bubbling here, and jQuery-specific API info here.
To specify some sub element as unclickable write the css hierarchy as in the example below.
In this example I stop propagation to any elements (*) inside td inside tr inside a table with the class ".subtable"
$(document).ready(function()
{
$(".subtable tr td *").click(function (event)
{
event.stopPropagation();
});
});
You can check whether the target is not your div-element and then issue another click event on the parent after which you will "return" from the handle.
$('clickable').click(function (event) {
let div = $(event.target);
if (! div.is('div')) {
div.parent().click();
return;
}
// Then Implement your logic here
}
Here is a non jQuery solution that worked for me.
<div style="background:cyan; width:100px; height:100px;" onclick="if (event.srcElement==this) {console.log('outer');}">
<a style="background:red" onclick="console.log('inner');">Click me</a>
</div>
for those that are not using jQuery
document.querySelector('.clickable').addEventListener('click', (e) =>{
if(!e.target.classList.contains('clickable')) return
// place code here
})
In case someone had this issue using React, this is how I solved it.
scss:
#loginBackdrop {
position: absolute;
width: 100% !important;
height: 100% !important;
top:0px;
left:0px;
z-index: 9; }
#loginFrame {
width: $iFrameWidth;
height: $iFrameHeight;
background-color: $mainColor;
position: fixed;
z-index: 10;
top: 50%;
left: 50%;
margin-top: calc(-1 * #{$iFrameHeight} / 2);
margin-left: calc(-1 * #{$iFrameWidth} / 2);
border: solid 1px grey;
border-radius: 20px;
box-shadow: 0px 0px 90px #545454; }
Component's render():
render() {
...
return (
<div id='loginBackdrop' onClick={this.props.closeLogin}>
<div id='loginFrame' onClick={(e)=>{e.preventDefault();e.stopPropagation()}}>
... [modal content] ...
</div>
</div>
)
}
By a adding an onClick function for the child modal (content div) mouse click events are prevented to reach the 'closeLogin' function of the parent element.
This did the trick for me and I was able to create a modal effect with 2 simple divs.
If a child element is clicked, then the event bubbles up to the parent and event.target !== event.currentTarget.
So in your function, you can check this and return early, i.e.:
var url = $("#clickable a").attr("href");
$("#clickable").click(function(event) {
if ( event.target !== event.currentTarget ){
// user clicked on a child and we ignore that
return;
}
window.location = url;
return true;
})
This is what you are looking for
mousedown event. this works on every DOM elements to prevent javascript focus handler like this:
$('.no-focus').mousedown(function (e) {
e.prevenDefault()
// do stuff
}
in vue.js framework, you can use modifier like this:
<span #mousedown.prevent> no focus </span>
Note that using on the input will prevent text selection handler
add a as follows:
....
or return false; from click handler for #clickable like:
$("#clickable").click(function() {
var url = $("#clickable a").attr("href");
window.location = url;
return false;
});
All solution are complicated and of jscript. Here is the simplest version:
var IsChildWindow=false;
function ParentClick()
{
if(IsChildWindow==true)
{
IsChildWindow==false;
return;
}
//do ur work here
}
function ChildClick()
{
IsChildWindow=true;
//Do ur work here
}
<a onclick="return false;" href="http://foo.example">I want to ignore my parent's onclick event.</a>

Click body but not two divs

Here's my function:
document.querySelector('body').addEventListener('click',e=>{getRandomImagePair()});
When I click anywhere on the body something happens. I have two divs .more and .wd and if I click on them the function getRandomImagePair() executes. How can I make so that if I click the links the function doesn't fire?
I tried this below, it works but then the .more div won't trigger another needed different function.
$('.more, .wd').on('click', function(event) {
event.stopPropagation();
});
Using event delegation, just check the className of the event.target element. Use an if statement in your event handler callback to prevent getRandomImagePair from being called a link was clicked on:
function getRandomImagePair() {
console.log('getRandomImagePair called');
}
//using event delegation
document.querySelector('body').addEventListener('click', e => {
if (e.target.className !== 'wd' && e.target.className !== 'more') {
getRandomImagePair();
}
});
.wd,
.more {
color: blue;
text-decoration: underline;
}
<body>
<div class="more">.more</div>
<div class="wd">.wd</div>
<p>Here is some other stuff</p>
<p>that when clicked on should still fire event handler</p>
</body>
Try excluding the items you don't want to be affected by the click :
const getRandomImagePair = () => {
alert("clicked")
}
$('body :not(".more, .wd")').on('click', getRandomImagePair);
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<button>Yep</button>
<button class="more">Nope</button>
<button class="wd">Nope</button>
<button>Yep</button>

Prevent function execution twice within two triggered events

I have the following code:
myInput.change(function (e) { // this triggers first
triggerProcess();
});
myButton.click(function (e) { // this triggers second
triggerProcess();
});
The problem with the above is when I click myButton both events are triggered and triggerProcess() is fired twice which is not desired.
I only need triggerProcess() to fire once. How can I do that?
Small demo
You can have a static flag that disables any more triggers once the first trigger has occurred. Might look something like this:
var hasTriggered = false;
myInput.change(function (e) { // this triggers first
triggerProcess();
});
myButton.click(function (e) { // this triggers second
triggerProcess();
});
function triggerProcess () {
// If this process has already been triggered,
// don't execute the function
if (hasTriggered) return;
// Set the flag to signal that we've already triggered
hasTriggered = true;
// ...
}
For resetting the hasTriggered flag, that's entirely up to you and how this program works. Maybe after a certain event occurring in the program you'd want to reenable the ability to trigger this event again — all you'd need to do it set the hasTriggered flag back to true.
You can use the mousedown event, which will fire before the input is blurred, and then check if the input has focus by checking if it's the activeElement, and if it does have focus, don't fire the mousedown event, as the change event will fire instead.
Additionally, if you want a mousedown event to occur when the value hasn't changed, and the change event doesn't fire, you'll need a check for that as well
var myInput = $('#test1'),
myButton = $('#test2'),
i = 0;
myInput.change(function(e) { // this triggers first
$(this).data('prev', this.value);
triggerProcess();
});
myButton.mousedown(function(e) { // this triggers second
var inp = myInput.get(0);
if (document.activeElement !== inp || inp.value === myInput.data('prev'))
triggerProcess();
});
function triggerProcess() {
console.log('triggered : ' + (++i))
}
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<input id="test1">
<br />
<br />
<button id="test2">
Click
</button>
In a fairly typical scenario where you have an input with a button next to ie, eg quick search.
You want to fire when the input changes (ie onblur) but also if the user clicks the button.
In the case where the user changes the input then clicks the button without changing input focus (ie no blur), the change event fires because the text has changed and the click event fires because the button has been clicked.
One option is to debounce the desired event handler.
You can use a plugin or a simple setTimeout/clearTimeout, eg:
$('#inp').change(debounceProcess)
$('#btn').click(debounceProcess);
function debounceProcess() {
if (debounceProcess.timeout != null)
clearTimeout(debounceProcess.timeout);
debounceProcess.timeout = setTimeout(triggerProcess, 100)
}
function triggerProcess() {
console.log('process')
}
<script src="https://ajax.googleapis.com/ajax/libs/jquery/1.9.1/jquery.min.js"></script>
<input id="inp">
<button id="btn">Click</button>
Use a real <button>BUTTON</button>. If you click on input text, alert is triggered, then once you leave the input text to click anywhere else, that unfocuses the input text which triggers the change event, so now 2 events have been triggered from the text input.
This is an assumption since the code provided is far from sufficient to give a complete and accurate answer. The HTML is needed as well as more jQuery/JavaScript. What is myInput and myButton actually referring to, etc.?
So I bet if you change...
var myButton = $('{whatever this is}'); and <input type='button'>
...TO:
var myButton = $("button"); and <button></button>
...you should no longer have an event trigger twice for an element.
This is assuming that triggerProcess() is a function that does something that doesn't manipulate the event chain or anything else involving events. This is an entirely different ballgame if instead of click() and change() methods you are using .trigger() or triggerHandler(), but it isn't. I'm not certain why such complex answers are derived from a question with very little info...?
BTW, if myInput is a search box and myButton is the button for myInput, as freedomn-m has mentioned, simply remove:
myButton.click(...
Leave myButton as a dummy. The change event is sufficient in that circumstance.
SNIPPET
var xInput = $('input');
var xButton = $('button'); //«———Add
xInput.on('change', alarm);
xInput.on('click', alarm);
xButton.on('click', alarm);
function alarm() {
return alert('Activated')
}
/* For demo it's not required */
[type='text'] {
width: 5ex;
}
b {
font-size: 20px;
}
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<form id='f1' name='f1'>
<input type='text'>
<input type='button' value='BUTTON TYPE'>
<label><b>⇦</b>Remove this button</label>
<button>BUTTON TAG</button>
<label><b>⇦</b>Replace it with this button</label>
</form>

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