has_attached_file :file, ComfyPress.config.upload_file_options.merge(
    # dimensions accessor needs to be set before file assignment for this to work
    :styles => lambda { |f|
      if f.respond_to?(:instance) && f.instance.respond_to?(:dimensions)
        (f.instance.dimensions.blank?? { } : { :original => f.instance.dimensions }).merge(