I have searched for a good solution everywhere, yet I can't find one which does not use jQuery.
Is there a cross-browser, normal way (without weird hacks or easy to break code), to detect a click outside of an element (which may or may not have children)?
Add an event listener to document and use Node.contains() to find whether the target of the event (which is the inner-most clicked element) is inside your specified element. It works even in IE5
const specifiedElement = document.getElementById('a')
// I'm using "click" but it works with any event
document.addEventListener('click', event => {
const isClickInside = specifiedElement.contains(event.target)
if (!isClickInside) {
// The click was OUTSIDE the specifiedElement, do something
}
})
var specifiedElement = document.getElementById('a');
//I'm using "click" but it works with any event
document.addEventListener('click', function(event) {
var isClickInside = specifiedElement.contains(event.target);
if (isClickInside) {
alert('You clicked inside A')
} else {
alert('You clicked outside A')
}
});
div {
margin: auto;
padding: 1em;
max-width: 6em;
background: rgba(0, 0, 0, .2);
text-align: center;
}
Is the click inside A or outside?
<div id="a">A
<div id="b">B
<div id="c">C</div>
</div>
</div>
You need to handle the click event on document level. In the event object, you have a target property, the inner-most DOM element that was clicked. With this you check itself and walk up its parents until the document element, if one of them is your watched element.
See the example on jsFiddle
document.addEventListener("click", function (e) {
var level = 0;
for (var element = e.target; element; element = element.parentNode) {
if (element.id === 'x') {
document.getElementById("out").innerHTML = (level ? "inner " : "") + "x clicked";
return;
}
level++;
}
document.getElementById("out").innerHTML = "not x clicked";
});
As always, this isn't cross-bad-browser compatible because of addEventListener/attachEvent, but it works like this.
A child is clicked, when not event.target, but one of it's parents is the watched element (i'm simply counting level for this). You may also have a boolean var, if the element is found or not, to not return the handler from inside the for clause. My example is limiting to that the handler only finishes, when nothing matches.
Adding cross-browser compatability, I'm usually doing it like this:
var addEvent = function (element, eventName, fn, useCapture) {
if (element.addEventListener) {
element.addEventListener(eventName, fn, useCapture);
}
else if (element.attachEvent) {
element.attachEvent(eventName, function (e) {
fn.apply(element, arguments);
}, useCapture);
}
};
This is cross-browser compatible code for attaching an event listener/handler, inclusive rewriting this in IE, to be the element, as like jQuery does for its event handlers. There are plenty of arguments to have some bits of jQuery in mind ;)
How about this:
jsBin demo
document.onclick = function(event){
var hasParent = false;
for(var node = event.target; node != document.body; node = node.parentNode)
{
if(node.id == 'div1'){
hasParent = true;
break;
}
}
if(hasParent)
alert('inside');
else
alert('outside');
}
you can use composePath() to check if the click happened outside or inside of a target div that may or may not have children:
const targetDiv = document.querySelector('#targetDiv')
document.addEventListener('click', (e) => {
const isClickedInsideDiv = e.composedPath().includes(targetDiv)
if (isClickedInsideDiv) {
console.log('clicked inside of div')
} else {
console.log('clicked outside of div')
}
})
I did a lot of research on it to find a better method. JavaScript method .contains go recursively in DOM to check whether it contains target or not. I used it in one of react project but when react DOM changes on set state, .contains method does not work. SO i came up with this solution
//Basic Html snippet
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>Document</title>
</head>
<body>
<div id="mydiv">
<h2>
click outside this div to test
</h2>
Check click outside
</div>
</body>
</html>
//Implementation in Vanilla javaScript
const node = document.getElementById('mydiv')
//minor css to make div more obvious
node.style.width = '300px'
node.style.height = '100px'
node.style.background = 'red'
let isCursorInside = false
//Attach mouseover event listener and update in variable
node.addEventListener('mouseover', function() {
isCursorInside = true
console.log('cursor inside')
})
/Attach mouseout event listener and update in variable
node.addEventListener('mouseout', function() {
isCursorInside = false
console.log('cursor outside')
})
document.addEventListener('click', function() {
//And if isCursorInside = false it means cursor is outside
if(!isCursorInside) {
alert('Outside div click detected')
}
})
WORKING DEMO jsfiddle
using the js Element.closest() method:
let popup = document.querySelector('.parent-element')
popup.addEventListener('click', (e) => {
if (!e.target.closest('.child-element')) {
// clicked outside
}
});
To hide element by click outside of it I usually apply such simple code:
var bodyTag = document.getElementsByTagName('body');
var element = document.getElementById('element');
function clickedOrNot(e) {
if (e.target !== element) {
// action in the case of click outside
bodyTag[0].removeEventListener('click', clickedOrNot, true);
}
}
bodyTag[0].addEventListener('click', clickedOrNot, true);
Another very simple and quick approach to this problem is to map the array of path into the event object returned by the listener. If the id or class name of your element matches one of those in the array, the click is inside your element.
(This solution can be useful if you don't want to get the element directly (e.g: document.getElementById('...'), for example in a reactjs/nextjs app, in ssr..).
Here is an example:
document.addEventListener('click', e => {
let clickedOutside = true;
e.path.forEach(item => {
if (!clickedOutside)
return;
if (item.className === 'your-element-class')
clickedOutside = false;
});
if (clickedOutside)
// Make an action if it's clicked outside..
});
I hope this answer will help you !
(Let me know if my solution is not a good solution or if you see something to improve.)
Related
I have a list of ids, when one of them is clicked I want to give it the attribute .className="open.
So far what I've done is to put all ids in a list and try to loop through them.
const memberB = document.querySelectorAll('#memberA, #memberAA, #memberAAA ');
for (var i = 0; i < memberB.length; i++) {
memberB[i].onclick = function(){
alert(memberB[i])
if(memberB[i].className=="open"){
memberB[i].className="";
}
else{
memberB[i].className="open";
}
}
What did I do wrong, I try to alert to see if I get the element that i clicked, all i get is 'undefined'.
you can use forEach to loop the NodeList which use querySelectorAll method, and use addEventListener to watch click event happen on all the elements you selected. Finally, use Element.classList.toggle method to toggle the class open or close
there is an example of toggle its background color after click
const members = document.querySelectorAll('.member');
members.forEach(member => {
member.addEventListener('click', e => {
e.target.classList.toggle('hight-light');
});
});
.member {
background-color: gray;
}
.hight-light {
background-color: green;
}
<div class="container">
<div class="member">1</div>
<div class="member hight-light">2</div>
<div class="member">3</div>
<div class="member">4</div>
</div>
I have a code snippet I like to keep around to do these kind of things in a single event listener
window.addEvent = (event_type, target, callback) => {
document.addEventListener(event_type, function (event) {
// If the event doesn't have a target
// Or the target doesn't look like a DOM element (no matches method
// Bail from the listener
if (event.target && typeof (event.target.matches) === 'function') {
if (!event.target.matches(target)) {
// If the element triggering the event is contained in the selector
// Copy the event and trigger it on the right target (keep original in case)
if (event.target.closest(target)) {
const new_event = new CustomEvent(event.type, event);
new_event.data = { originalTarget: event.target };
event.target.closest(target).dispatchEvent(new_event);
}
} else {
callback(event);
}
}
});
};
then in your case I'd do this
window.addEvent('click', '#memberA,#memberAA,#memberAAA', (event) => {
event.target.classList.toggle('open');
});
The script runs befor the DOM elements load.
You can put the script as a function inside an $(document).ready such that it runs after all the elements have been loaded.
$(document).ready(
function () {
const memberB = document.querySelectorAll('#memberA, #memberAA, #memberAAA ');
for (let i = 0; i < memberB.length; i++) {
memberB[i].onclick = function () {
//alert(memberB[i])
if (memberB[i].className === "open") {
memberB[i].className = "";
} else {
memberB[i].className = "open";
}
alert(memberB[i].className)
}
}
})
<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script>
<button id="memberA">A</button>
<button id="memberAA">AA</button>
<button id="memberAAA">AAA</button>
Let me know if this works!
I'm building a decision tree in JavaScript. I do not have jQuery available to me for this project.
I would like to be able to have buttons, placed anywhere in the decision tree (Hidden or displayed anywhere on the page), with the same class name. The listener on the JS side would then run a function.
Here is what I am using for and ID based listener. It works well but I need to be able to have multiple buttons with the same class or name available. Although I have seen examples of this, I cannot get it to function properly.
function q1a1() {
var q1a1button = document.getElementById("q1answer1");
if(q1a1button.addEventListener){
q1a1button.addEventListener("click", function() { q1answer1();}, false);
} else if(q1a1button.attachEvent){
q1a1button.attachEvent("onclick", function() { q1answer1();});
}
};
if(window.addEventListener){
window.addEventListener("load", q1a1, false);
} else if(window.attachEvent){
window.attachEvent("onload", q1a1);
} else{
document.addEventListener("load", q1a1, false);
}
function q1answer1() {
//DO SOME STUFF
}
This also needs to work in as many versions of IE as possible. For single class handling I'm using querySelectorAll.
What you are really looking for is JavaScript Event Delegation. In your case, you have BUTTON elements, which I'm going to assume are <button> tags. Now you want to know when one of those buttons was clicked and then run a function:
if (document.addEventListener) {
document.addEventListener("click", handleClick, false);
}
else if (document.attachEvent) {
document.attachEvent("onclick", handleClick);
}
function handleClick(event) {
event = event || window.event;
event.target = event.target || event.srcElement;
var element = event.target;
// Climb up the document tree from the target of the event
while (element) {
if (element.nodeName === "BUTTON" && /foo/.test(element.className)) {
// The user clicked on a <button> or clicked on an element inside a <button>
// with a class name called "foo"
doSomething(element);
break;
}
element = element.parentNode;
}
}
function doSomething(button) {
// do something with button
}
Anywhere on the page that a <button class="foo">...</button> element appears, clicking it, or any HTML tag inside of it, will run the doSomething function.
Update: Since Event Delegation is used, only a single click handler is registered on the document object. If more <button>s are created as a result of an AJAX call, you don't have to register click handlers on those new <button>s since we take advantage of the click event bubbling up from the element the user clicked on to the document object itself.
If you don't have jquery:
if (document.body.addEventListener){
document.body.addEventListener('click',yourHandler,false);
}
else{
document.body.attachEvent('onclick',yourHandler);//for IE
}
function yourHandler(e){
e = e || window.event;
var target = e.target || e.srcElement;
if (target.className.match(/keyword/))
{
//an element with the keyword Class was clicked
}
}
If you use a cross browser library like jquery:
HTML:
<div class="myClass">sample</div>
<div class="myClass">sample 2</div>
JS:
function theFuncToCall(event){
//func code
}
$(document).on('click', '.myClass', theFuncToCall);
var buttons = document.querySelectorAll(".MyClassName");
var i = 0, length = buttons.length;
for (i; i < length; i++) {
if (document.addEventListener) {
buttons[i].addEventListener("click", function() {
// use keyword this to target clicked button
});
} else {
buttons[i].attachEvent("onclick", function() {
// use buttons[i] to target clicked button
});
};
};
This answer is a bit overkill, but it should show you ways you could structure your code in a "modern" way even if you're still targeting old browsers
Write code to add event listeners so there is minimal difference between new and old browsers
var listen = (function () { // will return the handler for use in unlisten
if (window.addEventHandler) {
return function (node, type, handler) {
node.addEventListener(type, handler);
return handler;
};
} else if (window.attachEvent) {
return function (node, type, handler) {
var fn = function (e) {
if (!e) {
e = window.event;
}
if (!e.target && e.srcElement) {
e.target = e.srcElement;
}
return handler.call(this, e);
};
node.attachEvent('on' + type, fn);
return fn;
};
} else {
throw new Error('Events not supported in this environment');
// or
// return function ... node['on' + type] = function () { ... };
}
}());
and if you'd like the reverse, too
var unlisten = (function () { // use handler given by listen
if (window.removeEventListener) {
return function (node, type, handler) {
node.removeEventListener(type, handler);
};
} else if (window.detachEvent) {
return function (node, type, handler) {
node.detachEvent('on' + type, handler);
};
} else {
throw new Error('Events not supported in this environment');
// or
// return function ... node['on' + type] = null;
}
}());
Write your click handler
function clickHandler(e) {
// do stuff
}
Wrap your click handler in a function to choose only clicks on buttons with the right class
function wrappedClickHandler(e) {
var tokens, i;
if (e.target.tagName !== 'INPUT' && e.target.tagName !== 'BUTTON') {
return;
}
tokens = (e.target.className || '').split(' ');
for (i = 0; i < tokens.length; ++i) {
if (tokens[i] === 'theClassTokenWeWant') {
return clickHandler.call(this, e);
// or
// return clickHandler.call(e.target, e);
}
}
}
Add this as a listener to a common ancestor node
var h = listen(document, 'click', wrappedClickHandler);
// .. later, if desired
unlisten(document, 'click', h);
Would the simpler way of writing the event delegation function be to add it to the container of the buttons? For example,
// Select Container Element
const questionContainer = document.querySelector(".container");
// Listen For Clicks Within Container
questionContainer.onclick = function (event) {
// Prevent default behavior of button
event.preventDefault();
// Store Target Element In Variable
const element = event.target;
// If Target Element Is a Button
if (element.nodeName === 'BUTTON') {
// Event Code
}
}
I'm trying to create web-page, and to improve performance, I decide to use event delegation, instead of direct binding, but I came across with strange behavior of event delegation or I missed something...
Here is structure of my HTML
<div>
<section class="myClass" data-link="section 1">
<h1>Heading 1</h1>
<p>Some text....</p>
</section>
</div>
I want to entire section was clickable, but while clicking h1 or p element in section event.target on that moment is h1 or p and not section, so expression in if statement fails...
function delegate(ele) {
ele.parentNode.addEventListener("click", function (e) {
if (e.target.nodeName.toLowerCase() === "section" && e.target.classList.contains("myClass")) {
console.log("delegate " + e.target.getAttribute("data-link"));
}
}, false);
}
I already have solution with direct binding, but it would be good is achieved in the same result with event delegation.
Here is jsFiddle
function direct(ele) {
[].forEach.call(ele, function (value, index, array) {
value.addEventListener("click", function(e) {
console.log("direct " + value.getAttribute("data-link"));
}, false);
});
}
Thanks in advance!
Once you handled the click, you can walk the visual tree, starting from the target, to find the information you need.
You might seek by type (node name), by tag, ... for the sake of the example, i just seek on element up to get a 'data-link' attribute if i don't find one on the target, but you have many choices here.
Edit : another idea is to use event.currentTarget, to get the element on which you hooked the event.
The updated fiddle will print :
delegate call on h1 or p of section 1
when you click on h1 or p1
and it will print :
delegate section 1
when you click on the whole section.
http://jsfiddle.net/KMJnA/4/
function delegate(ele) {
ele.parentNode.addEventListener("click", delegateHandler, false);
}
function delegateHandler (e) {
var target = e.target;
var attribute = target.getAttribute("data-link");
// if target has no attribute
// seek it on its parent
if (!attribute) {
attribute = target.parentNode.getAttribute("data-link");
}
if ( target.classList.contains("myClass") ) {
console.log("delegate " + attribute);
}
else console.log('delegate call on h1 or p of ' + attribute);
}
Rq : i didn't get why you hook the event on the parent of the element, might be simpler not to do it. :-)
I found the solution with CSS pointer-events
jsFiddle with CSS
.myClass * {
pointer-events: none;
}
or with JavaScript
jsFiddle with JavaScript
(function () {
"use strict";
var ele = document.querySelector(".myClass").parentNode;
delegate(ele);
function delegate(ele) {
ele.addEventListener("click", function (e) {
var target = e.target;
while (!(target.nodeName.toLowerCase() === "section" && target.classList.contains("myClass"))) {
target = target.parentNode;
if (target === ele) {
break;
}
}
if (target.nodeName.toLowerCase() === "section" && target.classList.contains("myClass")) {
console.log("delegate " + target.getAttribute("data-link"));
}
});
}
}());
Add the event listener to ele instead of ele.parentNode, and use this instead of e.target.
Demo
function delegate(ele) {
ele.addEventListener("click", function (e) {
if (this.nodeName.toLowerCase() === "section" && this.classList.contains("myClass")) {
console.log("delegate " + this.getAttribute("data-link"));
}
}, false);
}
Be aware that e.target is the element the event was dispatched on. But in your case you don't want that, you want the element which has the event handler, so use this (or ele).
Is there a js listener for when a user scrolls in a certain textbox that can be used? Kinda like onclick except for scrolling. I saw HTML5 event listener for number input scroll - Chrome only but that seems to be for chrome only. I'm looking for something cross-browser.
For those who found this question hoping to find an answer that doesn't involve jQuery, you hook into the window "scroll" event using normal event listening. Say we want to add scroll listening to a number of CSS-selector-able elements:
// what should we do when scrolling occurs
function runOnScroll(element) {
// not the most exciting thing, but a thing nonetheless
console.log(element);
};
// grab elements as array, rather than as NodeList
const elements = document.querySelectorAll(`...`);
// and then make each element do something on scroll
elements.forEach(element => {
window.addEventListener(
"scroll",
() => runOnScroll(element),
{ passive: true }
);
});
Or alternatively, bind a single scroll listener, with evt => runOnScroll(evt) as handler and then figure out what to do with everything in elements inside the runOnScroll function instead.
Note that we're using the passive attribute to tell the browser that this event won't interfere with scrolling itself. This is important if we want smooth scrolling behaviour (and also means we shouldn't do perform reflow-triggering DOM updates during scroll).
For bonus points, you can give the scroll handler a lock mechanism so that it doesn't run if we're already scrolling:
// global lock, so put this code in a closure of some sort so you're not polluting.
let locked = false;
let lastCall = false;
function runOnScroll(element) {
if(locked) return;
if (lastCall) clearTimeout(lastCall);
lastCall = setTimeout(() => {
runOnScroll(element);
// you do this because you want to handle the last
// scroll event, even if it occurred while another
// event was being processed.
}, 200);
// ...your code goes here...
locked = false;
};
I was looking a lot to find a solution for sticy menue with old school JS (without JQuery). So I build small test to play with it. I think it can be helpfull to those looking for solution in js.
It needs improvments of unsticking the menue back, and making it more smooth.
Also I find a nice solution with JQuery that clones the original div instead of position fixed, its better since the rest of page element dont need to be replaced after fixing. Anyone know how to that with JS ?
Please remark, correct and improve.
<!DOCTYPE html>
<html>
<head>
<script>
// addEvent function by John Resig:
// http://ejohn.org/projects/flexible-javascript-events/
function addEvent( obj, type, fn ) {
if ( obj.attachEvent ) {
obj['e'+type+fn] = fn;
obj[type+fn] = function(){obj['e'+type+fn]( window.event );};
obj.attachEvent( 'on'+type, obj[type+fn] );
} else {
obj.addEventListener( type, fn, false );
}
}
function getScrollY() {
var scrOfY = 0;
if( typeof( window.pageYOffset ) == 'number' ) {
//Netscape compliant
scrOfY = window.pageYOffset;
} else if( document.body && document.body.scrollTop ) {
//DOM compliant
scrOfY = document.body.scrollTop;
}
return scrOfY;
}
</script>
<style>
#mydiv {
height:100px;
width:100%;
}
#fdiv {
height:100px;
width:100%;
}
</style>
</head>
<body>
<!-- HTML for example event goes here -->
<div id="fdiv" style="background-color:red;position:fix">
</div>
<div id="mydiv" style="background-color:yellow">
</div>
<div id="fdiv" style="background-color:green">
</div>
<script>
// Script for example event goes here
addEvent(window, 'scroll', function(event) {
var x = document.getElementById("mydiv");
var y = getScrollY();
if (y >= 100) {
x.style.position = "fixed";
x.style.top= "0";
}
});
</script>
</body>
</html>
Wont the below basic approach doesn't suffice your requirements?
HTML Code having a div
<div id="mydiv" onscroll='myMethod();'>
JS will have below code
function myMethod(){ alert(1); }
If scroll event is not working for some reason then try wheel event instead:
document.addEventListener('wheel', (event) => {console.log('scrolled')});
Is there a js listener for when a user scrolls in a certain textbox that can be used?
DOM L3 UI Events spec gave the initial definition but is considered obsolete.
To add a single handler you can do:
let isTicking;
const debounce = (callback, evt) => {
if (isTicking) return;
requestAnimationFrame(() => {
callback(evt);
isTicking = false;
});
isTicking = true;
};
const handleScroll = evt => console.log(evt, window.scrollX, window.scrollY);
document.defaultView.onscroll = evt => debounce(handleScroll, evt);
For multiple handlers or, if preferable for style reasons, you may use addEventListener as opposed to assigning your handler to onscroll as shown above.
If using something like _.debounce from lodash you could probably get away with:
const handleScroll = evt => console.log(evt, window.scrollX, window.scrollY);
document.defaultView.onscroll = evt => _.debounce(() => handleScroll(evt));
Review browser compatibility and be sure to test on some actual devices before calling it done.
let lastKnownScrollPosition = 0;
let ticking = false;
function doSomething(scrollPos) {
// Do something with the scroll position
}
document.addEventListener('scroll', function(e) {
lastKnownScrollPosition = window.scrollY;
if (!ticking) {
window.requestAnimationFrame(function() {
doSomething(lastKnownScrollPosition);
ticking = false;
});
ticking = true;
}
});
I want to listen for events on <p> elements at window or document level as there are too many such elements to attach an onclick event hander for each.
This is what I've got:
window.onload=function()
{
window.addEventListener('click',onClick,false);
}
function onClick(event)
{
alert(event.target.nodeName.toString());
}
I need advice on the code above, is it good?
And also, how can I check if the clicked element is a <p> element other than checking nodeName?
For example, if the <p> element contains a <b> element and that is clicked, the nodeType will be b not p.
Thank you.
I think it is good, and you can perform checking this way
var e = event.target
while (e.tagName != 'P')
if (!(e = e.parentNode))
return
alert(e)
If I was you I'd register for the "load" event in the same way that you are for "click". It's a more modern way of event handling, but might not be supported by some older browsers.
Checking the nodeName is the best way to interrogate the node:
function onClick(event) {
var el = event.target;
while (el && "P" != el.nodeName) {
el = el.parentNode;
}
if (el) {
console.log("found a P!");
}
}
Consider this:
(function () {
// returns true if the given node or any of its ancestor nodes
// is of the given type
function isAncestor( node, type ) {
while ( node ) {
if ( node.nodeName.toLowerCase() === type ) {
return true;
}
node = node.parentNode;
}
return false;
}
// page initialization; runs on page load
function init() {
// global click handler
window.addEventListener( 'click', function (e) {
if ( isAncestor( e.target, 'p' ) ) {
// a P element was clicked; do your thing
}
}, false );
}
window.onload = init;
})();
Live demo: http://jsfiddle.net/xWybT/