ruby-on-rails - 导轨中的错误？关于继承的模型

Question

My env: ruby-1.9.2-preview3; rails-3.0.0.beta3

---

class PostFather < ActiveRecord::Base
  def self.inherited(subclass)
  end
end

class Post < PostFather
end

---

在控制台中：

---

> Post.new # => TypeError: can't dup NilClass
> Post.all # => TypeError: can't dup NilClass
> Post.scoped # => TypeError: can't dup NilClass

---

你可以自己试试；

Answer 1

ActiveRecord 正在使用继承的方法，你需要调用 super 以便 ActiveRecord 的东西仍然运行：

class PostFather < ActiveRecord::Base
  def self.inherited(subclass)
    super(subclass)
  end
end