私は次のモデルを持っています:
class User < ActiveRecord::Base
has_one :image_assignment, as: :imageable
has_one :image, through: :image_assignment
end
class ImageAssignment < ActiveRecord::Base
belongs_to :image
belongs_to :imageable, polymorphic: true
end
class Image < ActiveRecord::Base
mount_uploader :image, ImageUploader
end
u = User.new
u.create_image #=> undefined method `create_image'