Clone a file input element in Javascript
Solution 1:
Guessing that you need this functionality so you can clone the input element and put it into a hidden form which then gets POSTed to a hidden iframe...
IE's element.clone() implementation doesn't carry over the value for input type="file", so you have to go the other way around:
// Clone the "real" input element
var real = $("#categoryImageFileInput_" + id);
var cloned = real.clone(true);
// Put the cloned element directly after the real element
// (the cloned element will take the real input element's place in your UI
// after you move the real element in the next step)
real.hide();
cloned.insertAfter(real);
// Move the real element to the hidden form - you can then submit it
real.appendTo("#some-hidden-form");
Solution 2:
Editing the file form field is a security risk and thus is disabled on most browsers and should be disabled on firefox. It is not a good idea to rely on this feature. Imagine if somebody was able, using javascript, to change a hidden file upload field to, lets say,
c:\Users\Person\Documents\Finances
Or
C:\Users\Person\AppData\Microsoft\Outlook.pst
:)
Solution 3:
In jQuery fileupload widget there is a file input replace method to get around the change event listener only firing once.
https://github.com/blueimp/jQuery-File-Upload/blob/master/js/jquery.fileupload.js#L769
(_replaceFileInput method in jquery.fileupload.js)