How to Capture changing value of textbox - javascript

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.

Related

How to call a function when default browser autocomplete list item selected [duplicate]

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.

event.PreventDefault doesnt work until end of function

I have a checkbox on which i am trying to send an ajax request based on its position. It is true by default. I want to be able to click it, and get a dialog that asks me if I want to discard my changes,and this dialog depends on the fact that the checkbox is not yet false.
$("input[type='checkbox']").click(function(evt) {
evt.preventDefault();
alert(this.checked);
if(checkEdited()){
var result = confirm("Do you want to continue?");
}
});
function checkEdited(){
var checkbox = $("div.managerContent input[type='checkbox']");
if(!checkbox.checked){
return false;
}
else{
//check other stuff
}
}
And everytime, I am getting false in the alert. In the browser, when I click the checkbox the check goes away, i get the alert, and then the check comes back.. checkEdited() is also used in other places
Everywhere I look to find how to stop a checkbox change event and assign it a value later just tells me to use .click and e.prenventDeafult()
Any ideas? Thanks so much!
You should attempt to capture the event before the click is complete, you can do this with mousedown like so:
$("input[type='checkbox']").on('mousedown',function(evt) {
evt.preventDefault();
alert(this.checked);
});
Here is a demo with a working example of capturing it before it changes
JSFIDDLE DEMO

JQuery - What method can I use to get this code to run without clicking

Ok this example code contains a button. Forget about the button, it does not exist, cannot be referenced and cannot be edited.
The buttons dont exist in this example - they merely represent another process. However the fields still need to be updated from values. Sorry I couldn't explain it better.
Answer:
http://jsfiddle.net/piezack/X8D4M/56/
If you want the event to fire whenever the text inside the box changes, then I think you're best off using jquery's keyup event instead of blur:
$('#FormCustomObject6Name').keyup(
function()
{
var x = $('#FormCustomObject6Id').val();
$("a[href*='http://www.msn.com']").attr('href',('http://www.google.com/search?q='+ x));
$('a#link').text('Link has been updated');
}
);
The only problem with this is that it won't catch instances where users enter data without using their keyboard (paste via right click, etc.).
You could use a mouseover event, say over the button or the link.
I changed this
$('.butter').mouseover(function(){
to have a mouseover the button.
Example: http://jsfiddle.net/X8D4M/39/
You can trigger events on objects yourself manually by using trigger(event).
So this might work for you:
$('button.butter').trigger('click');
Did you try just triggering a click?
$('button.butter').click();
Here's what you're looking for.
$('#FormCustomObject6Name').trigger('blur');
Okay, this is probably not the most efficient solution, but if you use setInterval to check for the changed value you're guaranteed to cover all sources of the change.
setInterval(function(){
var id = $('#FormCustomObject6Id').val();
var name = x + $('#FormCustomObject6Name').val();
if (id.length > 0 && name.length > 0){
$("a[href*='http://www.msn.com']").attr('href',('http://www.google.com/search?q='+ id));
$('a#link').text('Link has been updated');
}
},500);

Can jQuery check whether input content has changed?

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.

Jquery : how to trigger an event when the user clear a textbox

i have a function that currently working on .keypress event when the user right something in the textbox it do some code, but i want the same event to be triggered also when the user clear the textbox .change doesn't help since it fires after the user change the focus to something else
Thanks
The keyup event will detect if the user has cleared the box as well (i.e. backspace raises the event but backspace does not raise the keypress event in IE)
$("#inputname").keyup(function() {
if (!this.value) {
alert('The box is empty');
}
});
jsFiddle
As Josh says, this gets fired for every character code that is pressed in the input. This is mostly just showing that you need to use the keyup event to trigger backspace, rather than the keypress event you are currently using.
The solution by Jonathon Bolster does not cover all cases. I adapted it to also cover modifications by cutting and pasting:
$("#inputname").on('change keyup copy paste cut', function() {
//!this.value ...
});
see http://jsfiddle.net/gonfidentschal/XxLq2/
Unfortunately it's not possible to catch the cases where the field's value is set using javascript. If you set the value yourself it's not an issue because you know when you do it... but when you're using a library such as AngularJS that updates the view when the state changes then it can be a bit more work. Or you have to use a timer to check the value.
Also see the answer for Detecting input change in jQuery? which suggests the 'input' event understood by modern browsers. So just:
$("#inputname").on('input', function() {
//!this.value ...
});
Another way that does this in a concise manner is listening for "input" event on textarea/input-type:text fields
/**
* Listens on textarea input.
* Considers: undo, cut, paste, backspc, keyboard input, etc
*/
$("#myContainer").on("input", "textarea", function() {
if (!this.value) {
}
});
You can check the value of the input field inside the on input' function() and combine it with an if/else statement and it will work very well as in the code below :
$( "#myinputid" ).on('input', function() {
if($(this).val() != "") {
//Do action here like in this example am hiding the previous table row
$(this).closest("tr").prev("tr").hide(); //hides previous row
}else{
$(this).closest("tr").prev("tr").show(); //shows previous row
}
});
Inside your .keypress or .keyup function, check to see if the value of the input is empty. For example:
$("#some-input").keyup(function(){
if($(this).val() == "") {
// input is cleared
}
});
<input type="text" id="some-input" />

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