jQuery - Create hidden form element on the fly

Question

What is the simplest way to dynamically create a hidden input form field using jQuery?

Komi

Answer 1

$('<input>').attr('type','hidden').appendTo('form');

To answer your second question:

$('<input>').attr({
    type: 'hidden',
    id: 'foo',
    name: 'bar'
}).appendTo('form');

Fluvial

Note that IE will choke if you attempt to change the input type after it's created. Use $('<input type="hidden">').foo(...) as a workaround. – Piston

Also, jQuery documentation suggests that since DOM manipulation is expensive, if you have multiple inputs to be added, add all of them once using something like $(this).append(hidden_element_array.join('')); – Delldella

I just tried this method with jQuery 1.6.2 and recieved this error with Firefox 7.0.1: "uncaught exception: type property can't be changed" It seems that you cant use the attr method to change the type property under these conditions. I'm now trying the method below... – Difference

Will this same approach work with the newer .prop function in the newer API release? – Grader

@Grader .prop is not "the new .attr" as a lot of people seems to think. You should still use .attr to set attributes. – Fluvial

I had trouble with this approach when I tried to add valid HTML for the input field, as I was unable to add either a </input> or <input /> type of field. If anyone knows a solution, that would be very helpful – Convolvulus

Answer 2

$('#myformelement').append('<input type="hidden" name="myfieldname" value="myvalue" />');

Mcrae

Did someone test this answer on old IE? – Aircrew

Personally, I believe this is a much better approach than the accepted answer as it involves less DOM manipulation/function calls. – Fontanez

@Fontanez For the given case, yes you are correct, but it isn't always so. Take a look here https://mcmap.net/q/93748/-which-is-better-string-html-generation-or-jquery-dom-element-creation – Accompanyist

Answer 3

The same as David's, but without attr()

$('<input>', {
    type: 'hidden',
    id: 'foo',
    name: 'foo',
    value: 'bar'
}).appendTo('form');

Murraymurre

Is there a name for this way of populating a tag? – Arianna

how to append the input only 1 time? if its exist it keep entering new value with same attribute – Upholstery

Very streamlined, I love it. – Perrin

Answer 4

if you want to add more attributes just do like:

$('<input>').attr('type','hidden').attr('name','foo[]').attr('value','bar').appendTo('form');

Or

$('<input>').attr({
    type: 'hidden',
    id: 'foo',
    name: 'foo[]',
    value: 'bar'
}).appendTo('form');

Babin

this is giving console error Unexpected identifier . – Brownedoff

Second code, seems the "id" need to be generated dynamically something like foo1, foo2 etc – Mediocre

Answer 5

function addHidden(theForm, key, value) {
    // Create a hidden input element, and append it to the form:
    var input = document.createElement('input');
    input.type = 'hidden';
    input.name = key; //name-as-seen-at-the-server
    input.value = value;
    theForm.appendChild(input);
}

// Form reference:
var theForm = document.forms['detParameterForm'];

// Add data:
addHidden(theForm, 'key-one', 'value');

Caryopsis

What is the 'name-as-seen-at-the-server'? – Prate

Answer 6

Working JSFIDDLE

If your form is like

<form action="" method="get" id="hidden-element-test">
      First name: <input type="text" name="fname"><br>
      Last name: <input type="text" name="lname"><br>
      <input type="submit" value="Submit">
</form> 
    <br><br>   
    <button id="add-input">Add hidden input</button>
    <button id="add-textarea">Add hidden textarea</button>

You can add hidden input and textarea to form like this

$(document).ready(function(){

    $("#add-input").on('click', function(){
        $('#hidden-element-test').prepend('<input type="hidden" name="ipaddress" value="192.168.1.201" />');
        alert('Hideen Input Added.');
    });

    $("#add-textarea").on('click', function(){
        $('#hidden-element-test').prepend('<textarea name="instructions" style="display:none;">this is a test textarea</textarea>');
        alert('Hideen Textarea Added.');
    });

});

Check working jsfiddle here

Psychopathy