Rails Admin dropzone config

project.rb

class Project < ActiveRecord::Base
  extend FriendlyId
  friendly_id :title, use: :slugged
	has_and_belongs_to_many :artists
	has_many :gallery_images
	belongs_to :category

	has_attached_file :hero, styles: { large: "1280x1024>", medium: "650x650" }
  validates_attachment_content_type :hero, content_type: /\Aimage\/.*\Z/

  # Method
  def create_associated_image(image)
    gallery_images.create(image: image)
  end

end

rails_admin.rb

RailsAdmin.config do |config|

  config.model 'Project' do
    list do
      exclude_fields_if do
        type == :datetime
      end

      exclude_fields :gallery_images
      exclude_fields :artists
    end
  end


  config.model 'Artist' do
    list do
      exclude_fields_if do
        type == :datetime
      end

    end
  end

  config.model 'Category' do
    list do
      exclude_fields_if do
        type == :datetime
      end

    end
  end


  config.actions do
    dashboard                     # mandatory
    index                         # mandatory
    new

    dropzone do
      only Project
    end

    export
    bulk_delete
    show
    edit
    delete
    show_in_app

  end
end