Conditional trigger support for presence of file in file upload field

Hi there,

Wondering if it'd be feasible to extend a conditional trigger to the file upload component. Currently you can't trigger things based on the value of an upload field, but you can for most other component types (file components are not available in the 'if' drop down).

My use case is that if a user does not select a file, they don't get to answer additional text-based questions.

I realize file inputs are bit tricky compared to testing other types of input components, but I think it would be nice to complete the conditionals with access to this logic.

I've come up with my own Javascript for testing this to change the way the upload widget looks (classes and CSS), but I think someone could extend it to work for Webform Conditional checks:

var f = $('.file-upload-wrapper');
var l = $('.file-upload-wrapper label');
var t = l.text(); // Original label text

if (f.find('.form-item input.form-file').val() !== '') {
    f.addClass('loaded removable');
  }
  
  f.on("change", ".form-item input.form-file", function(){
    if (jQuery(this).val() !== '') {
      f.addClass('loaded');
      l.text('File Ready!');
    }
    else {
      f.removeClass('loaded');
      l.text(t);
    }
  });