Javascript: Fire onChange by setting a value programatically - javascript

I know that an onChange event will fire if the value of a field is changed, so is it possible to fire the onChange via Chrome console by setting the property of a field programatically?
The field in question is an input field, with an onChange attached to update a div with its new value.
The problem is the onChange callback method is firing when it shouldn't be, and i need to test whether one of the set up methods is causing the callback to fire when it assigns the fields default value

Try something like this please:
<input id="numberBox" data-dojo-type="dijit.form.NumberTextBox" />
<script>
dojo.connect( dijit.byId('numberBox'), "onChange", function ( event ) {
dijit.byId('numberBox').set('value', 12345 );
});
dijit.byId('numberBox').onChange();
</script>

Related

HTML datetime-local change event?

Is there a way to handle "datetime-selection" event with <input type='datetime-local'> control?
onchange, onselect and oninput does not work for me.
(In chrome) the onchange event triggers when the field is completely filled
Also have a read of Why is HTML5 input type datetime removed from browsers already supporting it?
Since onchange does not occur until after the field is fully filled in I ended up doing an onselect that sends new Date() to the onchange handler if the field does not yet have a value. This eliminates the false sense of a value being set (perhaps on a backing object) on the field before the time part of dateime-local is set.

What event to know when user has entered data into form?

I have a HTML form. I want to enable/disable a button until user eneters text in one of the fields. I am adding an event attribute to the which triggers some javascript. This javascript will enable/disable the button.
Problem is I can't figure out what event attribute to use. What event attribute please will trigger as soon as user enters data? I tried onchange but that only gets called when i clicked back outside the text area. So it may aswell be onblur.
You can use the input
function activateForm (event) {
if(!this.value == ""){
}
}
var input = document.querySelector(".myInput");
input.addEventListener("input", activateForm , false)
There are 2 possible events that can be used: either onChange or onKeyPress. onChange will trigger when the value of an input has changed while onKeyPress will trigger every time the user types something in a text box. The onChange triggers once the user has CHANGED something in the value, and got out of the input focus. That means the user has to hit TAB or click somewhere else for the event to trigger, hence why onKeyPress might be better suited.
Read more:
http://www.w3schools.com/jsref/event_onchange.asp
http://www.w3schools.com/jsref/event_onkeypress.asp
Younger browsers also support onInput which should certainly be prefered for now, if you do not need to support older browsers.

onChange event not firing when input changed dynamically

On my form, I have a DropDown, when a value is selected, I fire some JavaScript that populates some visible <input type="text" /> fields (under neath the drop down).
The problem is, I also want to run some JavaScript function whenever the value of one of these inputs changes, I want this function to run even if the text input is changed by the drop down selection.
Here is my current code:
jQuery(document).ready(function() {
$('#mainPane').on('change', '#formElementFromEmail', function(event){
var collectFromDropDown = $('#formElementFromEmail');
persistHiddenInputForCollectFromValue();
});
});
I suspect the change event is not being fired because no one has manually changed the value of the field in question. How can I overcome this?
Since you're using jQuery, you can trigger the event:
$('#mainPane').trigger('change');
you can simulate change event by
var element = document.getElementById('formElementFromEmail');
element.onchange();

Javascript : onchange event does not fire when value is changed in onkeyup event [duplicate]

This question already has an answer here:
The "onchange" event does not work with "value" change in "text input" object
(1 answer)
Closed 10 years ago.
I have this simply code :
<body>
<input type="text" onkeyup="this.value = (new Date()).getSeconds()" onchange="alert(1)" />
</body>
I dont't know why the textbox value has changed when i press the key but the onchange event does not fire.
How can i fire onchange event ?
The onchange will fire when you leave the focus from it (if you performed any changes). This behavior occurs only with text and textarea input types because javascript doesn't know when you're done typing.
I don't know why there is a checkbox in the code, but whatever. Sincerely, I'm not being able to tell you why, but the problem is the dynamic value change on the input (a guess would be that the change isn't performed by the user, but I really don't know), if you remove the code inside the onkeyup it will work. Whatever, if what you want is to execute some code when the input loses focus, you can use onblur instead, is more accurate in that case.

Event binding for keyboard input or change through javascript

I have an input field with id myinput , and have change event bind to this field through,
$("input#myinput").change(function(){
alert("the value is changed");
}
But the handler is not getting called, if I change the value through javascript
$("input#myinput").val(text);
But, it works if I enter the input through keyboard.
so, it seems like I am binding to wrong event. What should I do to bind to both keyboard input and JS value update (jQuery val() here).
thanks.
change is triggered only by user events. With jQuery you can use trigger('change') to trigger the change event programatically.
JS Fiddle demo.

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