Multiple file upload?

[ErnaOudman]

It would be nice to also have a widget that can be used for uploading multiple files, using the "multiple" attribute of the file input form.

I might have missed it, but I believe this widget isn't available in deform. Is there a specific reason not to support this?

[stevepiercy]

This is possible now that arbitrary attributes can be added to any widget. However the UI is suboptimal. It would need some fixing up to be practical.

After a brief search, I found a jQuery plugin that supports both Bootstrap 4 and 3, and doesn't suck: https://github.com/kartik-v/bootstrap-fileinput.

Alternatively it can be handled through a sequence of file uploads.

I would accept a PR with a proposed enhancement and functional tests in both Deform and deformdemo.