File selector
The selector :file selects elements of type file, which are file upload fields. The equivalent of $(':file') is $('[type=file]'). Since :file is not part of the CSS specification, for better performance in modern browsers it is better to use [type='file'] instead.
Syntax
This is how we select elements with type file:
$(':file');
As with other pseudo-class selectors (those starting with ':'), it is better to precede ':' with the name of a tag or another selector, otherwise the selector '*' will be applied, i.e. $(':file') will be treated as $('*:file'), so it is better to use $('input:file') instead.
Example
Let's select all inputs with the type file and give them a green background and a red border using the css method:
<form>
<input type="button" value="button">
<input type="file">
<input type="password">
<button>button</button>
<input type="reset">
<input type="radio" name="test">
<input type="radio" name="test">
<input type="checkbox">
<input type="text">
</form>
<+javascript+>
$('form input:file').css({background: 'green', border: '2px red solid'});
$('form').submit(function(event) {
event.preventDefault(); // prevents form submission
});
<-javascript->
