Capture the size of textarea dynamically through javascript - javascript

how to trigger a event in jquery when the value of a textarea is changing without losing focus form textarea.

You can use the keyup event to get the value as it's entered, like this:
$("textarea").keyup(function() {
var newVal = $(this).val();
});
Or, to be a bit safer:
$("textarea").bind("keyup paste change", function() {
var newVal = $(this).val();
});
Unlike only using change this will get the value as it updates, instead of when the <textarea> loses focus.

You could use keypress(), although that's not strictly tied to the change of a value, just the events of a key being pressed.
$("textarea").keypress(
function() {
var newValue = $(this).val();
}
);

You can use the Autoresize with this jquery:
JQUERY PLUGIN: ‘AUTORESIZE’

Related

JS prevent firing focusout event if input didn't changed

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();
});

getting new value of input field on keypressed

i have an input field where i allow users to insert an integer.
Now when ever they insert a value into the input field i check with ajax if it is higher than a specefic amount for this purpose i need to get the "new" value of the input field
i have tried the following:
$('.wanted_amount').keydown(function () {
var value = $(this).val();
}
however this returns ""
Meaning that it doesnt register the value untill after keydown
So how i can i get the new value of the input field with javascript?
can you please try this,
$(function(){
$('.wanted_amount').keyup(function () {
var value = $(this).val(); // alert(value);
});
});
keydown is event, which helps to trigger event when detects a finger on a key
keyup is event, which helps to trigger event when the key is released
You have not closed function properly.
keydown() will be triggered when key is pressed and keyup() will be triggered after pressing the key. In your case, keyup() is more suitable.
Try this:
$('.wanted_amount').keyup(function () {
var value = $(this).val();
console.log(value);
});
Fiddle here.

How can I detect when the value in input text is changed by a script?

I have an input text that I need detect when the text (value) change.
The value can be changed in two ways:
Allow to the user write in it.
The user click a button, runs a jQuery event and fill it with the
result.
For the item 1 I solved using keyup but for the item 2 I have no idea how can I detect when the text is changed.
I try change() but does not work.
You can use .trigger() inside your function where you fill the input.
$("#idOfButton").click(function() {
//do some stuff
//fill input
$("#edit").val("new stuff!").triggerHandler("keyup"); //<--Trigger keyup event
});
Demo: http://jsfiddle.net/Q8fCa/1
Add event handler on change() for item2 and in item1 keyup handler, trigger item2 change() event. Simple like that...
"runs a jQuery event and fill it with the result."
you can call another function from your jquery event.
$('sel').click(function(){
textedited(); // call your new function.
});
You can create an interval that checks whether the value of the input field has changed in every occasion (user input or button click) :
var oldValue = $('#field').val();
var newValue = oldValue;
var checkInputFieldInterval = window.setInterval(function() {
newValue = $('#field').val();
if (newValue !== oldValue) {
// VALUE CHANGED, DO STUFF
oldValue = newValue;
}
}, 100);
Note the the "100" is the interval period in ms. You can find more information about the setInterval() method on this page http://www.w3schools.com/jsref/met_win_setinterval.asp
You can do...
$('.name').on('keyup', function(){
/* I'll run when the button is clicked or there's a keyup event. */
})
$('button').on('click', function(){
$('.name').val('Bill').trigger('keyup');
})
Here's a quick demo: http://jsbin.com/uteceb/1/edit

How do I get curent value of text element via jQuery

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;
}
});
});

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.

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