Is it possible to bind javascript (jQuery is best) event to "change" form input value somehow?
I know about .change() method, but it does not trigger until you (the cursor) leave(s) the input field. I have also considered using .keyup() method but it reacts also on arrow keys and so on.
I need just trigger an action every time the text in the input changes, even if it's only one letter change.
There is a simple solution, which is the HTML5 input event. It's supported in current versions of all major browsers for <input type="text"> elements and there's a simple workaround for IE < 9. See the following answers for more details:
jQuery keyboard events
Catch only keypresses that change input?
Example (except IE < 9: see links above for workaround):
$("#your_id").on("input", function() {
alert("Change to " + this.value);
});
Yes, compare it to the value it was before it changed.
var previousValue = $("#elm").val();
$("#elm").keyup(function(e) {
var currentValue = $(this).val();
if(currentValue != previousValue) {
previousValue = currentValue;
alert("Value changed!");
}
});
Another option is to only trigger your changed function on certain keys. Use e.KeyCode to figure out what key was pressed.
You can also store the initial value in a data attribute and check it against the current value.
<input type="text" name="somename" id="id_someid" value="" data-initial="your initial value" />
$("#id_someid").keyup(function() {
return $(this).val() == $(this).data().initial;
});
Would return true if the initial value has not changed.
function checkChange($this){
var value = $this.val();
var sv=$this.data("stored");
if(value!=sv)
$this.trigger("simpleChange");
}
$(document).ready(function(){
$(this).data("stored",$(this).val());
$("input").bind("keyup",function(e){
checkChange($(this));
});
$("input").bind("simpleChange",function(e){
alert("the value is chaneged");
});
});
here is the fiddle http://jsfiddle.net/Q9PqT/1/
You can employ the use of data in jQuery and catch all of the events which then tests it against it's last value (untested):
$(document).ready(function() {
$("#fieldId").bind("keyup keydown keypress change blur", function() {
if ($(this).val() != jQuery.data(this, "lastvalue") {
alert("changed");
}
jQuery.data(this, "lastvalue", $(this).val());
});
});
This would work pretty good against a long list of items too. Using jQuery.data means you don't have to create a javascript variable to track the value. You could do $("#fieldId1, #fieldId2, #fieldId3, #fieldId14, etc") to track many fields.
UPDATE: Added blur to the bind list.
I had to use this kind of code for a scanner that pasted stuff into the field
$(document).ready(function() {
var tId,oldVal;
$("#fieldId").focus(function() {
oldVal = $("#fieldId").val();
tId=setInterval(function() {
var newVal = $("#fieldId").val();
if (oldVal!=newVal) oldVal=newVal;
someaction() },100);
});
$("#fieldId").blur(function(){ clearInterval(tId)});
});
Not tested...
I don't think there's a 'simple' solution. You'll probably need to use both the events onKeyUp and onChange so that you also catch when changes are made with the mouse. Every time your code is called you can store the value you've 'seen' on this.seenValue attached right to the field. This should make a little easier.
You can set events on a combination of key and mouse events, and onblur as well, to be sure. In that event, store the value of the input. In the next call, compare the current value with the lastly stored value. Only do your magic if it has actually changed.
To do this in a more or less clean way:
You can associate data with a DOM element (lookup api.jquery.com/jQuery.data ) So you can write a generic set of event handlers that are assigned to all elements in the form. Each event can pass the element it was triggered by to one generic function. That one function can add the old value to the data of the element. That way, you should be able to implement this as a generic piece of code that works on your whole form and every form you'll write from now on. :) And it will probably take no more than about 20 lines of code, I guess.
An example is in this fiddle: http://jsfiddle.net/zeEwX/
Since the user can go into the OS menu and select paste using their mouse, there is no safe event that will trigger this for you. The only way I found that always works is to have a setInterval that checks if the input value has changed:
var inp = $('#input'),
val = saved = inp.val(),
tid = setInterval(function() {
val = inp.val();
if ( saved != val ) {
console.log('#input has changed');
saved = val;
},50);
You can also set this up using a jQuery special event.
Related
I have a webpage with a small survey. I want to pre populate some of the answers based on user inputs to previous question.
In the below code, if value of id QR~QID3 depends upon value of QID1_Total. However after the page loaded and even if the condition is met the textbox is not populated with correct value.
.addOnload(function()
{
if(document.getElementById("QID1_Total").value>15) {
document.getElementById("QR~QID3").value = "Good";
}
else{
document.getElementById("QR~QID3").value = "Average";
}
});
$("#QID1_Total").on("input", function() {
//statements goes here
});
use of on("input" will track every inputting event, include drop and paste.
know more about onInput : https://mathiasbynens.be/notes/oninput
Here is an Fiddle Example to know how trigger works :
https://jsfiddle.net/5sotpa63/
An Assumption
Let Us Say you are using a function, which holds this statement show Good and Average according to users Input.
var targetElem = document.getElementById("QID1_Total");
var showComment = (targetElem,value>15) ? "Good" : "Average";
document.getElementById("QR~QID3").value = showComment;
Above code is the shorter method of your own statement mentioned in your question.
Now on Change of the target QR~QID3 you need to load some content. you utilize the below code as follows.
$("#QR~QID3").on("input", function() {
//your next question loading statements goes here,
//statements to proceed when you show some comment Good or Average
}).trigger("input");
Hope! this could be helpful.
$('#QID1_Total').keydown(function () {
//ur code
});
as the mouse key is pressed in the input field the function is called
You need to add an event listener to the "QID1_Total" element.
If you want to run the check while the user changes the input, i.e. after each keypress use the oninput event.
If you want to run the check after the user has completed the input, use the onchange event. The onchange event will only fire after the input loses focus.
You can bind the event listeners by using the addEventListener() function like this:
document.getElementById("QID1_Total").addEventListener("input", function(){
//Code goes here
});
Here is a JSFiddle showing both methods.
You also have to use the parseInt() function on the textbox values before you can perform mathematical functions with them.
I have a pretty simple form. When the user types in an input field, I want to update what they've typed somewhere else on the page. This all works fine. I've bound the update to the keyup, change and click events.
The only problem is if you select an input from the browser's autocomplete box, it does not update. Is there any event that triggers when you select from autocomplete (it's apparently neither change nor click). Note that if you select from the autocomplete box and the blur the input field, the update will be triggered. I would like for it to be triggered as soon as the autocomplete .
See: http://jsfiddle.net/pYKKp/ (hopefully you have filled out a lot of forms in the past with an input named "email").
HTML:
<input name="email" />
<div id="whatever"><whatever></div>
CSS:
div {
float: right;
}
Script:
$("input").on('keyup change click', function () {
var v = $(this).val();
if (v) {
$("#whatever").text(v);
}
else {
$("#whatever").text('<whatever>');
}
});
I recommending using monitorEvents. It's a function provide by the javascript console in both web inspector and firebug that prints out all events that are generated by an element. Here's an example of how you'd use it:
monitorEvents($("input")[0]);
In your case, both Firefox and Opera generate an input event when the user selects an item from the autocomplete drop down. In IE7-8 a change event is produced after the user changes focus. The latest Chrome does generate a similar event.
A detailed browser compatibility chart can be found here:
https://developer.mozilla.org/en-US/docs/Web/Events/input
Here is an awesome solution.
$('html').bind('input', function() {
alert('test');
});
I tested with Chrome and Firefox and it will also work for other browsers.
I have tried a lot of events with many elements but only this is triggered when you select from autocomplete.
Hope it will save some one's time.
Add "blur". works in all browsers!
$("input").on('blur keyup change click', function () {
As Xavi explained, there's no a solution 100% cross-browser for that, so I created a trick on my own for that (5 steps to go on):
1. I need a couple of new arrays:
window.timeouts = new Array();
window.memo_values = new Array();
2. on focus on the input text I want to trigger (in your case "email", in my example "name") I set an Interval, for example using jQuery (not needed thought):
jQuery('#name').focus(function ()
{
var id = jQuery(this).attr('id');
window.timeouts[id] = setInterval('onChangeValue.call(document.getElementById("'+ id +'"), doSomething)', 500);
});
3. on blur I remove the interval: (always using jQuery not needed thought), and I verify if the value changed
jQuery('#name').blur(function ()
{
var id = jQuery(this).attr('id');
onChangeValue.call(document.getElementById(id), doSomething);
clearInterval(window.timeouts[id]);
delete window.timeouts[id];
});
4. Now, the main function which check changes is the following
function onChangeValue(callback)
{
if (window.memo_values[this.id] != this.value)
{
window.memo_values[this.id] = this.value;
if (callback instanceof Function)
{
callback.call(this);
}
else
{
eval( callback );
}
}
}
Important note: you can use "this" inside the above function, referring to your triggered input HTML element. An id must be specified in order to that function to work, and you can pass a function, or a function name or a string of command as a callback.
5. Finally you can do something when the input value is changed, even when a value is selected from a autocomplete dropdown list
function doSomething()
{
alert('got you! '+this.value);
}
Important note: again you use "this" inside the above function referring to the your triggered input HTML element.
WORKING FIDDLE!!!
I know it sounds complicated, but it isn't.
I prepared a working fiddle for you, the input to change is named "name" so if you ever entered your name in an online form you might have an autocomplete dropdown list of your browser to test.
Detecting autocomplete on form input with jQuery OR JAVASCRIPT
Using: Event input. To select (input or textarea) value suggestions
FOR EXAMPLE FOR JQUERY:
$(input).on('input', function() {
alert("Number selected ");
});
FOR EXAMPLE FOR JAVASCRIPT:
<input type="text" onInput="affiche(document.getElementById('something').text)" name="Somthing" />
This start ajax query ...
The only sure way is to use an interval.
Luca's answer is too complicated for me, so I created my own short version which hopefully will help someone (maybe even me from the future):
$input.on( 'focus', function(){
var intervalDuration = 1000, // ms
interval = setInterval( function(){
// do your tests here
// ..................
// when element loses focus, we stop checking:
if( ! $input.is( ':focus' ) ) clearInterval( interval );
}, intervalDuration );
} );
Tested on Chrome, Mozilla and even IE.
I've realised via monitorEvents that at least in Chrome the keyup event is fired before the autocomplete input event. On a normal keyboard input the sequence is keydown input keyup, so after the input.
What i did is then:
let myFun = ()=>{ ..do Something };
input.addEventListener('change', myFun );
//fallback in case change is not fired on autocomplete
let _k = null;
input.addEventListener( 'keydown', (e)=>_k=e.type );
input.addEventListener( 'keyup', (e)=>_k=e.type );
input.addEventListener( 'input', (e)=>{ if(_k === 'keyup') myFun();})
Needs to be checked with other browser, but that might be a way without intervals.
I don't think you need an event for this: this happens only once, and there is no good browser-wide support for this, as shown by #xavi 's answer.
Just add a function after loading the body that checks the fields once for any changes in the default value, or if it's just a matter of copying a certain value to another place, just copy it to make sure it is initialized properly.
I have the following input:
<input name="video" value="" type="text">
And attached js event:
input.focusout(function(){
loadThumbnail();
});
The problem is it triggers always when focus leaves field. Actually it's goods behavior, but didn't fit my needs, because if user didn't changed the field the event will be triggered and the request will be made on server.
I've tried to replace it with change event, but it doesn't triggers when user clean's field.
So what I need is event that will be triggered after user finished editing the field and detect cases when user cleans field or moves focus to/from it, but don't change anything.
Would you suggest a solution?
Try something like this to save the old value and compare it with new value:
var oldVal = ''
input.focusout(function () {
var newVal = input.val();
if (oldVal != newVal) {
oldVal = newVal;
loadThumbnail();
}
});
Try the below part. You will have to tweak this. I just wrote a raw code for U.
var temp='';
input.focusin(function(){
temp = input.val();
});
input.focusout(function(){
if temp != input.val() then
loadThumbnail();
});
I have text input element and an event is fired on blur event and when user presses enter.
My problem is that if user inputs "foo" and presses enter val() function nevertheless returns null, after the blur event val() returns foo. As far as I understand it is due to the fact that value property of HTML input element is updated only when it looses focus. Could you please give me a work around.
Here is the exact code I use:
var meetmove_address_field_listener = function(e){
var type = $(this).attr('data-marker-type');;
var value = $(this).val();
meetmove_map.geocodeAddress(type, value);
};
$(document).ready(function(){
$('input[data-type="name"]').blur(meetmove_address_field_listener);
$('input[data-type="name"]').keypress(function(event){
if (event.which == 13){
event.preventDefault();
meetmove_address_field_listener(event);
return false;
}
});
});
The value can be accessed straight away, you just need to use the correct handler. .keypress() will fire before the character is displayed in the input. Try .keyup() instead of .keypress() and it should work.
Well really Sudahir answer solved my issue --- i was misusing $(this) reference that changes meaning depending on context. Bu he deleted his answer so here is the working code:
$(document).ready(function(){
$('input[data-type="name"]').blur(meetmove_address_field_listener);
$('input[data-type="name"]').keyup(function(event){
if (event.which == 13){
event.preventDefault();
var type = $(this).attr('data-marker-type');
var value = $(this).val();
meetmove_map.geocodeAddress(type, value);
return false;
}
});
});
How do I grab the value from an input box as its being entered?
onkeyup will be triggered every time a key is released. While it looks to be the solution it has some problems.
If the user move the cursor with the arrows, it is triggered and you have to check yourself if the field value didn't change.
If the user copy/paste a value in the input field with the mouse, or click undo/redo in the browser, onkeyup is not triggered.
Like in a mac or in google docs, I didn't want a save button to submit forms in our app, here is how I do it.
Any comment, or shortcut is welcome as it is a bit heavy.
onfocus, store the current value of the field, and start an interval to check for changes
when the user moves something in the input, there is a comparison with the old value, if different a save is triggered
onblur, when the user moves away from the field, clear the interval and event handlers
Here is the function I use, elm is the input field reference and after is a callback function called when the value is changed:
<html>
<head>
<title>so</title>
</head>
<body>
<input type="text" onfocus="changeField(this, fldChanged);">
<script>
function changeField(elm, after){
var old, to, val,
chk = function(){
val = elm.value;
if(!old && val === elm.defaultValue){
old = val;
}else if(old !== val){
old = val;
after(elm);
}
};
chk();
to = setInterval(chk, 400);
elm.onblur = function(){
to && clearInterval(to);
elm.onblur = null;
};
};
function fldChanged(elm){
console.log('changed to:' + elm.value);
}
</script>
</body>
</html>
use an onchange event handler for the input box.
http://www.htmlcodetutorial.com/forms/_INPUT_onChange.html
I noticed you used the "jquery" tag. For jQuery, you can use the .keypress() method.
From the API documentation:
Description: Bind an event handler to the "keypress" JavaScript
event, or trigger that event on an
element.
The event will fire every time keyboard input is registered by the browser.
.keydown() and .keyup() are also available. Their behavior is slightly different from .keypress() and is outlined by the API documentation as well.
The nice thing about jQuery is that you can use the same code across Firefox, IE, Safari, Opera and Chrome.