Question

我有一组对象，其中一些具有organization_id属性，另一些对象委托organization_id。

例如：

class Department
  belongs_to :organization
end
class Program
  belongs_to :department
  delegate :organization_id, to: :department
end

class Role
  belongs_to :organization
end
class UsersRole
  belongs_to :role
  delegate :organization_id, to: :role
end

我想用一种方法以编程方式确定将organization_id委派给哪个对象类，以便我可以执行以下操作

def find_organization_id_source(object)
   object.organization_id.method_im_hoping_exists
end
$ find_organization_id_source(@program)
>> Department
$ find_organization_id_source(@users_role)
>> Role

Answer 1

这是不可能的。从active_support/core_ext/module/delegation.rb的源代码中可以看出，Rails创建了一个内部调用委托方法的新方法。

Answer 2

def is_delegated?(object, delegated_attribute)
  object.attributes.include? delegated_attribute
end

它不会告诉你从哪里获得价值，但它应该告诉你你是否通过授权获得了它。

是否有可能以编程方式确定在ruby中委托方法的对象是什么？

2 个答案: