铁轨中的一个错误？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

---

你可以亲自尝试一下;

Answer 1

ActiveRecord正在使用继承方法，你需要调用super，以便ActiveRecord的东西仍在运行：

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