[whatwg] Make files attribute of the input element writable

[Jonas Sicking]

On Tue, May 22, 2012 at 10:41 AM, Nico Weber <thakis at chromium.org> wrote:
> Hi,
>
> The files attribute of the input element is currently marked readonly
> [1], to protect from `myInput.files = "/etc/passwd"; myForm.submit()`.
> Since its type is now FileList and not string, that's no longer
> necessary.
>
> Making the attribute writable would allow setting the files property
> of an input element to dataTransfer.files from a drop handler. For
> example, I would like to use this to create a larger drop-target for a
> file input. Here's one request for this functionality:
> http://stackoverflow.com/questions/8006715/drag-drop-files-into-standard-html-file-input
>
> Can the readonly restriction be removed from the spec?

I don't think simply marking the attribute as writable is the correct
solution here. At the very least we should make it possible to assign
a sequence<File> to the attribute such that you can do:

myInput.files = [file1];

But even a sequence<Blob> should be allowed IMO.

One concern I have though is that this is pretty problematic UI-wise.
Simply displaying the .name (if it's a file) property in the UI seems
like a good way to scare people into thinking that they have attached
something that they didn't.

/ Jonas