在相关模型更新销毁之前，错误不会传播

Question

我有一个父模型，通过诸如'@ client.update_attributes（params [：client]'之类的参数进行更新。在我的参数中是一个销毁'client_card'的调用。我在client_card上有一个before_destroy方法来防止它我的before_destroy方法正在运行，但是，更新时，before_destroy上的错误不会传播到相关模型。有关如何在更新时将此模型错误传播到关联模型的任何建议吗？

class Client < ActiveRecord::Base
  has_many :client_cards, :dependent => :destroy
  validates_associated :client_cards

class ClientCard < ActiveRecord::Base
  belongs_to :client, :foreign_key => 'client_id'

  attr_accessible :id, :client_id, :card_hash, :last_four, :exp_date

  before_destroy :check_relationships

  def check_finished_appointments
    appointments = Appointment.select { |a| a.client_card == self && !a.has_started }
    if(appointments && appointments.length > 0 )
      errors.add(:base, "This card is tied to an appointment that hasn't occurred yet.")
      return false
    else
      return true
    end
  end

end

Answer 1

我怀疑validates_associated只运行ClientCard的显式声明验证，并且不会触发你在before_destroy回调中添加的错误。你最好的选择可能是before_update上的Client回调：

class Client < ActiveRecord::Base
  has_many :client_cards, :dependent => :destroy

  before_update :check_client_cards

  # stuff

  def check_client_cards
    if client_cards.any_future_appointments?
      errors.add(:base, "One or more client cards has a future appointment.")
    end
  end
end

然后在ClientCard：

class ClientCard < ActiveRecord::Base
  belongs_to :client, :foreign_key => 'client_id'

  # stuff

  def self.any_future_appointments?
    all.detect {|card| !card.check_finished_appointments }
  end
end

Answer 2

它可能有效吗？如果您的控制器的删除操作正常重定向到索引，则您将永远不会看到错误，因为重定向会重新加载模型。