Hi @devr51! I was just working on File field myself, so thought I’d chime in.

In Piklist’s Developer Documentation for File (Upload) Field, they state that you need to omit 'basic' => true under options, if you want to use “WordPress media uploader”, otherwise it will use the “basic uploader”.

So if you have something like this:

piklist( 'field', array(
  'type'    => 'file',
  'field'   => 'my_upload_field',
  'label'   => 'Upload Field',
  'options' => array(
    'basic'        => true, // <=== REMOVE THIS, if you want to use WordPress media uploader
    'button'       => 'Add Image',
    'preview_size' => 'medium',
  ),
) );

Change it to this:

piklist( 'field', array(
  'type'    => 'file',
  'field'   => 'my_upload_field',
  'label'   => 'Upload Field',
  'options' => array(
    'button'       => 'Add Image',
    'preview_size' => 'medium',
  ),
) );

And it should switch to using “WordPress media uploader”.