- Detecting value change of input[type=text] in jQuery
- 11 Answers 11
- Update — 2021
- Original Answer
- Description
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- change event
- .on( «change» [, eventData ], handler ) Returns: jQuery
- version added: 1.7 .on( «change» [, eventData ], handler )
- Examples:
- Demo:
- .trigger( "change" ) Returns: jQuery
- version added: 1.0 .trigger( "change" )
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- How do I implement onchange of with jQuery?
- Jquery: bind load + change simultaneously
- 4 Answers 4
Detecting value change of input[type=text] in jQuery
I want to execute a function every time the value of a specific input box changes. It almost works with $(‘input’).keyup(function) , but nothing happens when pasting text into the box, for example. $input.change(function) only triggers when the input is blurred, so how would I immediately know whenever a text box has changed value?
@liho1eye paste is just one that I thought of, I’d rather listen for a definitive change than have to think of all the different incoming paths.
11 Answers 11
Update — 2021
As of 2021 you can use input event for all the events catering input value changes.
$("#myTextBox").on("input", function() < alert($(this).val()); >); Original Answer
just remember that ‘on’ is recommended over the ‘bind’ function, so always try to use a event listener like this:
$("#myTextBox").on("change paste keyup", function() < alert($(this).val()); >); Would be even better if using console.log() instead of alert . Would be very annoying for keyup to alert .
@cytsunny yea sure, alert is annoying, but in this case is an example of the code to be executed on the value change, it really can be any payload you want.
Just noticed the function is performed many times, just «input» is required without adding anything else
Description
You can do this using jQuery’s .bind() method. Check out the jsFiddle.
Sample
$("#myTextBox").bind("change paste keyup", function() < alert($(this).val()); >); More Information
This solution helped me to progress on my project.
$("#your_textbox").on("input propertychange",function()< // Do your thing here. >); Note: propertychange for lower versions of IE.
you can also use textbox events —
Basically, just account for each event:
$("#textbox").keyup(function() < alert($(this).val()); >); $("#textbox").change(function() < alert($(this).val()); >); $("#myTextBox").on("change paste keyup select", function() < alert($(this).val()); >); select for browser suggestion
DON’T FORGET THE cut or select EVENTS!
The accepted answer is almost perfect, but it forgets about the cut and select events.
cut is fired when the user cuts text (CTRL + X or via right click)
select is fired when the user selects a browser-suggested option
You should add them too, as such:
$("#myTextBox").on("change paste keyup cut select", function() < //Do your function >); change event
.on( «change» [, eventData ], handler ) Returns: jQuery
Description: Bind an event handler to the «change» event.
version added: 1.7 .on( «change» [, eventData ], handler )
This page describes the change event. For the deprecated .change() method, see .change() .
The change event is sent to an element when its value changes. This event is limited to elements, boxes and elements. For select boxes, checkboxes, and radio buttons, the event is fired immediately when the user makes a selection with the mouse, but for the other element types the event is deferred until the element loses focus.
For example, consider the HTML:
form>input class="target" type="text" value="Field 1">select class="target">option value="option1" selected="selected">Option 1 option>option value="option2">Option 2 option>select>form>div id="other">Trigger the handlerdiv>
The event handler can be bound to the text input and the select box:
$( ".target" ).on( "change", function( )alert( "Handler for `change` called." );> );
Now when the second option is selected from the dropdown, the alert is displayed. It is also displayed if you change the text in the field and then click away. If the field loses focus without the contents having changed, though, the event is not triggered. To trigger the event manually, use .trigger( "change" ) :
$( "#other" ).on( "click", function( )$( ".target" ).trigger( "change" );> );
After this code executes, clicks on Trigger the handler will also alert the message. The message will display twice, because the handler has been bound to the change event on both of the form elements.
As of jQuery 1.4, the change event bubbles in Internet Explorer, behaving consistently with the event in other modern browsers.
Note: Changing the value of an input element using JavaScript, using .val() for example, won't fire the event.
Examples:
Attaches a change event to the select that gets the text for each selected option and writes them in the div. It then triggers the event for the initial text draw.
html>html lang="en">head>meta charset="utf-8">title>on demo title>style>divcolor: red;>style>script src="https://code.jquery.com/jquery-3.7.0.js"> script>head>body>select name="sweets" multiple="multiple">option>Chocolate option>option selected="selected">Candy option>option>Taffy option>option selected="selected">Caramel option>option>Fudge option>option>Cookie option>select>div> div>script>$( "select" ).on( "change", function( )var str = "";$( "select option:selected" ).each( function( )str += $( this ).text() + " ";> );$( "div" ).text( str );> ).trigger( "change" );script>body>html>
Demo:
To add a validity test to all text input elements:
$( "input[type='text']" ).on( "change", function( )// Check input( $( this ).val() ) for validity here> );
.trigger( "change" ) Returns: jQuery
Description: Trigger the "change" event on an element.
version added: 1.0 .trigger( "change" )
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How do I implement onchange of with jQuery?
Note that change will only fire when the input element has lost focus. There is also the input event which fires whenever the textbox updates without it needing to lose focus. Unlike key events it also works for pasting/dragging text.
This is so useful, it is worth putting it in an answer. Currently (v1.8*?) there is no .input() convenience fn in jquery, so the way to do it is
$('input.myTextInput').on('input',function(e)< alert('Changed!') >);Since you can bind to multiple events $('form').on('change input', function); did the trick for me. Thanks.
@Norris. That will probably fire twice when an element is changed (1st), and loses focus (2nd). That is not a problem for many purposes, but is worth noting nevertheless.
Note, this will fire for every input change made (which might be what you're looking for). But, if you're looking for an event like "When done changing", here's a great example.
$('input[name=myInput]').change(function() < . >);However, this event will only fire when the selector has lost focus, so you will need to click somewhere else to have this work.
If that's not quite right for you, you could use some of the other jQuery events like keyup, keydown or keypress - depending on the exact effect you want.
Unfortunately, this doesn't work for a hidden input. A possible solution when required a onchange on a hidden input is: (with css)..
Note that change will only fire when the input element has lost focus. There is also the input event which fires whenever the textbox updates without it needing to lose focus. Unlike key events it also works for pasting/dragging text.
As I am trying this, and have just learned that the event only fires when two conditions are met: 1) value change; and 2) blur, I wonder if what many people expect of change() is better handled by keyup() ?
I would suggest using the keyup event something like below:
There are a few ways of achieving the same result so I guess it's down to preference and depends on how you want it to work exactly.
Update: This only works for manual input not copy and paste.
For copy and paste I would recommend the following:
$('elementName').on('input',function(e)< // Code here >);Contents of input element can be changed without keyup being fired. For example you can paste text using mouse.
I never knew about the 'input' function. That's the one to use, IMO, since it supports manual text entry as well as cut/pasted text.
$("#tbSearch").on('change keyup paste', function () < ApplyFilter(); >); function ApplyFilter() < var searchString = $("#tbSearch").val(); // . etc. >This works quite nicely, particularly when paired up with a jqGrid control. You can just type into a textbox and immediately view the results in your jqGrid .
There is one and only one reliable way to do this, and it is by pulling the value in an interval and comparing it to a cached value.
The reason why this is the only way is because there are multiple ways to change an input field using various inputs (keyboard, mouse, paste, browser history, voiceinput etc.) and you can never detect all of them using standard events in a cross-browser environment.
Luckily, thanks to the event infrastructure in jQuery, it’s quite easy to add your own inputchange event. I did so here:
$.event.special.inputchange = < setup: function() < var self = this, val; $.data(this, 'timer', window.setInterval(function() < val = self.value; if ( $.data( self, 'cache') != val ) < $.data( self, 'cache', val ); $( self ).trigger( 'inputchange' ); >>, 20)); >, teardown: function() < window.clearInterval( $.data(this, 'timer') ); >, add: function() < $.data(this, 'cache', this.value); >>;There is a demo here: http://jsfiddle.net/LGAWY/
If you’re scared of multiple intervals, you can bind/unbind this event on focus / blur .
Jquery: bind load + change simultaneously
In many cases, I need to bind a behaviour to an element after loading, and then after an event triggering (like "change"). I think the best way would be to make it in the same line:
$('#element_id').bind('load, change', function () < . >);4 Answers 4
I stumbled across the same problem. Removing comma is not enough, at least not in this case:
I guess load events get triggered before $(document).ready() .
This is a simple solution:
$(document).ready(function()< $('#element_id').bind('change', function () < . >); $('#element_id').trigger('change'); >);Even this will loop the change event a billion times. No idea why. I tried this method and others and it just keeps wanting to loop.
Are you triggering the event inside the function? It shouldn't loop, there must be an error somewhere. You can try making a minimal error case and posting code in a separate question; most likely you will figure it out before hitting "Post" button. 🙂
Not triggering it inside the function. $('#employeeDropDown').on('change', function (event) < var form = $(event.target).parents("form"); form.submit(); >).trigger('change'); or even as you put it above, will cause it to loop.
I think you are - form.submit() probably triggers change event too. Use console.log() (or JavaScript debugger if you like) to see which part is looping. But really, this has nothing to do with this question, you should post your own. I can assure you there is nothing in the answer above which would make it loop - I use it frequently and it works.
Bind is deprecated since jQuery 3.0, but this still works perfectly (just replace bind with on then call trigger . Also, this is the "correct" way to call this according to the documentation now, not sure what it read back in 2011. Calling load on a ready event is considered unsafe and will not run when scripts are loaded dynamically. See: api.jquery.com/ready