Question

型号：

class Factory < ActiveRecord::Base
  has_many :factory_workers
  has_many :workers, through: :factory_workers
end

class FactoryWorkers < ActiveRecord::Base
  belongs_to :factory
  belongs_to :worker

  before_destroy :union_approves?

  private

  def union_approves?
    errors.add(:proletariat, "is never destroyed!")

    false
  end
end

class Worker < ActiveRecord::Base
  has_many :factory_workers
  has_many :factorys, through: :factory_workers
end

如果我尝试通过Factory更新Factory的Workers列表，并导致一些FactoryWorker关联的破坏，我希望调用before_destroy挂钩，但似乎不是这种情况。

实施例

Factory.create(name: 'communist paradise', worker_ids: [1, 2])

Factory.find_by(name: 'commnist paradise').update(worker_ids: [1])
# before_destroy hook is not called, proletariat must riot!

如何在更新记录的关联时确保调用before_destory挂钩？

Answer 1

找到我需要的东西：ActiveRecord为关联提供了一个before_remove方法，所以我只需要重新调整如下：

class Factory < ActiveRecord::Base
  has_and_belongs_to_many :workers, before_remove: :union_approves?

  private

  def union_approves?
    ...
  end
end

验证has_many关联的破坏？

1 个答案: