Javascript – Clearing using jQuery

file-ioformshtmljavascriptjquery

Is it possible to clear an <input type='file' /> control value with jQuery? I've tried the following:

$('#control').attr({ value: '' });

But it's not working.

Best Answer

Easy: you wrap a <form> around the element, call reset on the form, then remove the form using .unwrap(). Unlike the .clone() solutions otherwise in this thread, you end up with the same element at the end (including custom properties that were set on it).

Tested and working in Opera, Firefox, Safari, Chrome and IE6+. Also works on other types of form elements, with the exception of type="hidden".

window.reset = function(e) {
  e.wrap('<form>').closest('form').get(0).reset();
  e.unwrap();
}

<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script>

<form>
  <input id="file" type="file">
  <br>
  <input id="text" type="text" value="Original">
</form>

<button onclick="reset($('#file'))">Reset file</button>
<button onclick="reset($('#text'))">Reset text</button>

JSFiddle

As Timo notes below, if you have the buttons to trigger the reset of the field inside of the <form>, you must call .preventDefault() on the event to prevent the <button> from triggering a submit.

EDIT

Does not work in IE 11 due to an unfixed bug. The text (file name) is cleared on the input, but its File list remains populated.

Related Solutions

Javascript – How to check if an element is hidden in jQuery

Since the question refers to a single element, this code might be more suitable:

// Checks CSS content for display:[none|block], ignores visibility:[true|false]
$(element).is(":visible");

// The same works with hidden
$(element).is(":hidden");

It is the same as twernt's suggestion, but applied to a single element; and it matches the algorithm recommended in the jQuery FAQ.

We use jQuery's is() to check the selected element with another element, selector or any jQuery object. This method traverses along the DOM elements to find a match, which satisfies the passed parameter. It will return true if there is a match, otherwise return false.

Javascript – How to convert a string to boolean in JavaScript

Do:

var isTrueSet = (myValue === 'true');

using the identity operator (===), which doesn't make any implicit type conversions when the compared variables have different types.

Don't:

You should probably be cautious about using these two methods for your specific needs:

var myBool = Boolean("false");  // == true

var myBool = !!"false";  // == true

Any string which isn't the empty string will evaluate to true by using them. Although they're the cleanest methods I can think of concerning to boolean conversion, I think they're not what you're looking for.