On css change event

JavaScript change Event

Summary: in this tutorial, you’ll learn about the JavaScript change event of the input text, radio button, checkbox, and select elements.

The change event occurs when the element has completed changing.

To attach an event handler to the change event of an element, you can either call the addEventListener() method:

element.addEventListener('change', function( )< // handle change >);Code language: JavaScript (javascript)

or use the onchange attribute of the element. For example:

input type="text" onchange="changeHandler()">Code language: HTML, XML (xml)

However, it is a good practice to use the addEventListener() method.

Using JavaScript change event for input elements

The change event of an element fires when the element loses focus. The change event does not fire when you’re tying.

The following example shows the value of the input text when it loses focus.

html> html lang="en"> head> meta charset="UTF-8"> meta name="viewport" content="width=device-width, initial-scale=1.0"> title>JavaScript change Event for Input Element title> head> body> label for="message">Message: label> input type="text" class="input" id="message" name="message"> button>Submit button> p id="result"> p> script> let input = document.querySelector('.input'); let result = document.querySelector('#result'); input.addEventListener('change', function ( ) < result.textContent = this.value; >); script> body> html>Code language: HTML, XML (xml)

In this example, if you type some text on the element and move focus to the button, the change event fires to show the entered text.

Note that if you want to handle every change of the value, you use the input event instead.

Using JavaScript change event for radio buttons

A radio button fires the change event after you select it.

The following example shows how to handle the change event of the radio buttons:

html> html lang="en"> head> meta charset="UTF-8"> meta name="viewport" content="width=device-width, initial-scale=1.0"> title>JavaScript change Event for Radio Buttons title> head> body> span>Status: span> input type="radio" id="pending" name="status"> label for="pending">Pending label> input type="radio" id="resolved" name="status"> label for="resolved">Resolved label> input type="radio" id="rejected" name="status"> label for="rejected">Rejected label> p id="result"> p> script> let result = document.querySelector('#result'); document.body.addEventListener('change', function (e) < let target = e.target; let message; switch (target.id) < case 'pending': message = 'The Pending radio button changed'; break; case 'resolved': message = 'The Resolved radio button changed'; break; case 'rejected': message = 'The Rejected radio button changed'; break; > result.textContent = message; >); script> body> html>Code language: HTML, XML (xml)

• First, register an event handler to the change event of the body . When a radio button is clicked, its change event is bubbled to the body. This technique is called event delegation.
• Then, show a corresponding message based on which radio button is selected.

Using JavaScript change event for checkboxes

Similar to radio buttons, checkboxes fire the change event after selection, whether checked or unchecked. For example:

html> html lang="en"> head> meta charset="UTF-8"> meta name="viewport" content="width=device-width, initial-scale=1.0"> title>JavaScript change Event for Checkboxes title> head> body> label for="status">Web Technology: label> input type="checkbox" id="html"> HTML input type="checkbox" id="css"> CSS input type="checkbox" id="js"> JavaScript p id="result"> p> script> let result = document.querySelector('#result'); document.body.addEventListener('change', function (e) < let target = e.target; let message; switch (target.id) < case 'html': message = 'The HTML checkbox changed'; break; case 'css': message = 'The CSS checkbox changed'; break; case 'js': message = 'The JavaScript checkbox changed'; break; > result.textContent = message; >); script> body> html>Code language: HTML, XML (xml)

Using JavaScript change event for the select element

The element fires the change event once the selection has completed.

The following example shows how to handle the change event of the element. The

element with the id result will display the selected item:

html> html lang="en"> head> meta charset="UTF-8"> meta name="viewport" content="width=device-width, initial-scale=1.0"> title>JavaScript change Event for Select element title> head> body> select id="lang"> option value="">Select a language option> option value="JavaScript">JavaScript option> option value="TypeScript">TypeScript option> option value="PHP">PHP option> option value="Python">Python option> option value="Java">Java option> select> p id="result"> p> script> let select = document.querySelector('#lang'); let result = document.querySelector('#result'); select.addEventListener('change', function ( ) < result.textContent = this.value; >); script> body> html>Code language: HTML, XML (xml)

• First, select the element by its id ( lang );
• Then, show the selected value in the

  element.

Summary

• The element fires the change event once it loses focus.
• The radio button, checkbox, and select elements fire the change event after they have been selected.

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HTMLElement: change event

The change event is fired for , , and elements when the user modifies the element’s value. Unlike the input event, the change event is not necessarily fired for each alteration to an element’s value .

Depending on the kind of element being changed and the way the user interacts with the element, the change event fires at a different moment:

Syntax

Use the event name in methods like addEventListener() , or set an event handler property.

addEventListener("change", (event) => >); onchange = (event) => >; 

Event type

Examples

element

HTML

label> Choose an ice cream flavor: select class="ice-cream" name="ice-cream"> option value="">Select One …option> option value="chocolate">Chocolateoption> option value="sardine">Sardineoption> option value="vanilla">Vanillaoption> select> label> div class="result">div> 

body  display: grid; grid-template-areas: "select result"; > select  grid-area: select; > .result  grid-area: result; > 

JavaScript

const selectElement = document.querySelector(".ice-cream"); const result = document.querySelector(".result"); selectElement.addEventListener("change", (event) =>  result.textContent = `You like $event.target.value>`; >); 

Result

Text input element

For some elements, including , the change event doesn’t fire until the control loses focus. Try entering something into the field below, and then click somewhere else to trigger the event.

HTML

input placeholder="Enter some text" name="name" /> p id="log">p> 

JavaScript

const input = document.querySelector("input"); const log = document.getElementById("log"); input.addEventListener("change", updateValue); function updateValue(e)  log.textContent = e.target.value; > 

Result

Specifications

Browser compatibility

BCD tables only load in the browser

Different browsers do not always agree whether a change event should be fired for certain types of interaction. For example, keyboard navigation in elements used to never fire a change event in Gecko until the user hit Enter or switched the focus away from the (see Firefox bug 126379). Since Firefox 63 (Quantum), this behavior is consistent between all major browsers, however.

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Event Detect When CSS Property Changed Using Jquery

Event detect when css property changed using Jquery

Note

Mutation events have been deprecated since this post was written, and may not be supported by all browsers. Instead, use a mutation observer.

Yes you can. DOM L2 Events module defines mutation events; one of them — DOMAttrModified is the one you need. Granted, these are not widely implemented, but are supported in at least Gecko and Opera browsers.

Try something along these lines:

document.documentElement.addEventListener('DOMAttrModified', function(e) if (e.attrName === 'style') console.log('prevValue: ' + e.prevValue, 'newValue: ' + e.newValue); 
>
>, false);

document.documentElement.style.display = 'block';

You can also try utilizing IE’s «propertychange» event as a replacement to DOMAttrModified . It should allow to detect style changes reliably.

Trigger event using Jquery on CSS change?

Binding to the window.resize is your best option (I believe). There isn’t any event fired when you change an element’s CSS. You can however optimize a bit by caching the selector used:

var $searcButton = $('#search-button');
$(window).resize(function() if($searcButton.css("display") == "none") //do something 
> else //do something else 
>
>);

Or you can use $(window).width() to check the width of the viewport:

var $window = $(window);
$window.resize(function() if($window.width() <= 480) //do something 
> else //do something else 
>
>);

You can always throttle your own event handler:

var $window = $(window), 
resize_ok = true, 
timer;

timer = setInterval(function () resize_ok = true;
>, 250);

$window.resize(function() if (resize_ok === true) resize_ok = false; 
if($window.width() <= 480) //do something 
> else //do something else 
> 
>
>);

This will prevent the code in your resize event handler from running more than once every quarter second.

JQuery: detecting css state change

It is expected of the checkbox value to remain 1 regardless of the checked state. In a classic form the checked state determins wether the value is sent or not, and not if the submission contains 1 or 0. What you’re looking for is probabily the «checked» attribute.

setting checked attribute:

$('#check').attr('checked'); // returns true / false

from what I’m aware of there is no easy way of checking for a property change other than checking at intervals in an infinite loop but I’m prety certain you don’t need to do that.
Clicking the label should change the checkbox «checked» attribute. If you need 1 or 0 value and not a «1 or nothing» you could listen to the checkbox «change» event and prevent de-checking, but instead change value to 0 if it is 1, or vice-versa.

$('#check').change(function(event) event.PreventDefault(); 
$(this).val( ( $(this).val( ) + 1 ) % 2 );
>);

However preventing the change also cancels any styling based on the checked property so you must refer to the checked state in another way: either in css using

or you could add a small piece of code to toggle a custom class

$('#check').change(function(event) event.PreventDefault(); 
$(this).val( ( $(this).val( ) + 1 ) % 2 ); 
$(this).toggleClass('checked');
>);

and refer to it from css like this:

CSS Property Change Listener

I think you’re looking for this:

document.documentElement.addEventListener('DOMAttrModified', function(e) if (e.attrName === 'style') console.log('prevValue: ' + e.prevValue, 'newValue: ' + e.newValue); 
>
>, false);

If you google for it, a bunch of stuff comes up. This looks promising though:

Is it possible to listen to a style change event?

Since jQuery is open-source, I would guess that you could tweak the css function to call a function of your choice every time it is invoked (passing the jQuery object). Of course, you’ll want to scour the jQuery code to make sure there is nothing else it uses internally to set CSS properties. Ideally, you’d want to write a separate plugin for jQuery so that it does not interfere with the jQuery library itself, but you’ll have to decide whether or not that is feasible for your project.

HTML detect change on style of element

You may use MutationObserver:

document.querySelector('button').addEventListener('click', function(e) < var ele = document.getElementById('corps'); if (ele.style.display == 'block') ele.style.display = 'none'; else ele.style.display = 'block';>);

var observer = new MutationObserver(function(mutationsList, observer) < for (var mutation of mutationsList)< console.log('The ' + mutation.attributeName + ' attribute was modified.'); >>);observer.observe(document.getElementById('corps'), < attributes: true>);

1111111111111111
Change div style

How to detect when CSS value has changed?

I might be mistaken but I am sure that there is no such thing than a «change event» for CSS styles. In some modern browsers there is a DOMSubtreeModified event, but I don’t think that this will even be triggered merely by changing an attribute like this.

So the only way to determine changes here would be to set an interval (window.setInterval) and check for changes every x milliseconds (choose a suitable x here).

JQuery Detect class changes

There is no event of class-added , you will need to track it yourself.

It can be done with an infinite loop with setTimeout to check if the class has changed.

function checkForChanges()
 if ($('.slide-out-div').hasClass('open')) 
$('.otherDiv').css('top','0px'); 
else 
setTimeout(checkForChanges, 500);
>

You can call the function when you want, or onDOM ready:

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