CODEWITHSUNDEEP
javascripthtmljquerytextfieldhidden
Raghu
Raghu

Reputation: 1161

How to set the value of an input hidden field to a value entered in another input text field using JavaScript?

I have an input textfield with the name qtyText, to which a user enters a value. I would like to set this value as the value for another hidden field named qtyTextHidden using JavaScript. How can I go about it?

HTML:

<input name = "qtyText" type = "textbox" size = "2" value = "" />
<input type="hidden"  value = "" name="qtyTextHidden"/>

My efforts to set the field value using JS works, but I am unable to send the value to the servlet. So, I am attempting to directly set the value using a function, and then trying to send it to the servlet. I would like to have a value = someJSFunction(), some kind. The function needs to trigger upon onChange event in the qtyText input field.

Upvotes: 3

Views: 36533

Answers (3)

Roman C
Roman C

Reputation: 1

To set the value of the hidden field the easiest way is to use the javascript function that to pass three parameters from, to, and form names: 

<script type="text/javascript">
    function someJSFunction(form, from, to){
      var el_from=form[from], el_to=form[to];
      el_to.value=el_from.value;
      return el_to.value;
    }
</script>
<form name="myform">
<input name = "qtyText" type = "textbox" size = "2" value = "" onchange="someJSFunction(myform, 'qtyText', 'qtyTextHidden')"/>
<input type="hidden"  value = "" name="qtyTextHidden"/>

Upvotes: 1

David Thomas
David Thomas

Reputation: 253308

I'd suggest:

function updateHidden(valueFrom, valueTo) {
    valueTo.value = valueFrom.value;
}

var inputs = document.getElementsByTagName('input'),
    textInputs = [],
    hiddenInputs = [],
    refersTo;

for (var i = 0, len = inputs.length; i < len; i++) {
    switch (inputs[i].type) {
        case 'hidden':
            hiddenInputs.push(inputs[i]);
            break;
        case 'text':
        default:
            textInputs.push(inputs[i]);
            break;
    }
}

for (var i = 0, len = textInputs.length; i < len; i++) {
    refersTo = document.getElementsByName(textInputs[i].name + 'Hidden')[0];
    if (refersTo !== null) {
        textInputs[i].onchange = function () {
            updateHidden(this, document.getElementsByName(this.name + 'Hidden')[0]);
        };
    }
}

JS Fiddle demo.

Incidentally: there is no type="textbox". At all. Ever. Anywhere in HTML, not even in HTML 5: it's type="text". The only reason it works with type="textbox" is because browsers are ridiculously forgiving and, if the type isn't understood, it defaults to type="text".

Upvotes: 1

user1386320
user1386320

Reputation:

Using jQuery:

$(document).ready(function() {
    $('input:text[name="qtyText"]').keyup(function() {
        $('input:hidden[name="qtyTextHidden"]').val( $(this).val() );
    });
});

Using JavaScript:

window.onload = function() {
    if(document.readyState == 'complete') {
        document.getElementsByTagName('input')[0].onkeyup = function() {
            document.getElementsByTagName('input')[1].value = this.value;
        };
    }
}:

Upvotes: 7

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