app/models/concerns/galleryable.rb
module Galleryable
extend ActiveSupport::Concern
included do
has_many :images, as: :imageable, dependent: :destroy
accepts_nested_attributes_for :images, allow_destroy: true, update_only: true
def image_url(style)
image.attachment.url(style) if image && image.attachment.exists?
end
end
end