ruby-on-rails - Ruby on Rails - 如何委托(delegate)给多态关联？

Question

是否可以在多态模型中使用 delegate 与 has_many 或 has_one 关联？它是如何工作的？

class Generic < ActiveRecord::Base
    ...

  belongs_to :generable, polymorphic: true

  delegate :file_url, to: :image, allow_nil: true
  delegate :type_cat, to: :cat, allow_nil: true
end

class Image < ActiveRecord::Base
   ...
  has_one :generic, as: generable, dependent: :destroy
end


class Cat < ActiveRecord::Base
   ...
  has_one :generic, as: generable, dependent: :destroy
end

Answer 1

不确定这是否与您想要做的完全匹配，因为很难从您的示例中看出，但是...

class Generic < ActiveRecord::Base
  ...
  belongs_to :generable, polymorphic: true
  ...
  delegate :common_method, to: :generable, prefix: true
end

class Cat
  def common_method
    ...
  end
end

class Image
  def common_method
    ...
  end
end

允许您说以下内容:

generic.generable_common_method