在rails上进行双重belong_to验证

Question

我有以下型号的

class School
has_many :classrooms
has_many :communications
end
class Classroom
belongs_to :school
end
class Communication
belongs_to :school
end

目前，我可以在通信中使用school_id，但由于业务逻辑的原因，我意识到我可能还必须对教室的通信进行索引，使模型如下所示：

class School
has_many :classrooms
has_many :communications
end
class Classroom
belongs_to :school
has_many :communications
end
class Communication
belongs_to :school
belongs_to :classroom, optional: true
end

我想要的是，沟通应该始终属于一所学校，但如果它属于一个教室，我想确保这个教室也属于同一所学校

我如何为这个案例编写验证？

Answer 1

对于这个案例，我最终创建了一个自定义验证器：

class ClassroomValidator < ActiveModel::Validator
def validate(record)
if record.classroom.school.id != record.school.id
record.errors.add :classroom, message: "Invalid relation between classroom and school"
end
end
end
class Communication < ApplicationRecord
belongs_to :school
belongs_to :classroom, optional: true

validates_with ClassroomValidator, if: -> { self.classroom != nil }

end