Rails belongs_to association并销毁没有看到原始记录的回调

Question

我有以下3个型号：

class ExitSurveyResponse < ActiveRecord::Base
  belongs_to :survey_response, dependent: :destroy
  belongs_to :attendance
end

class SurveyResponse < ActiveRecord::Base
  has_many :question_responses, class_name: 'SurveyQuestionResponse', dependent: :destroy
  has_one :exit_survey_response, dependent: :destroy
end

class SurveyQuestionResponse < ActiveRecord::Base
  attr_accessible :response
  validates :response, length: { maximum: 255 }
  belongs_to :survey_question
  belongs_to :survey_response

  before_destroy :destroy_attendance_cache

  private
  def destroy_attendance_cache
    logger.debug('The following is nil because it was already deleted')
    logger.debug("exit_survey_response: #{survey_response.exit_survey_response}")
  end
end

问题是，当我删除ExitSurveyResponse时，我需要修改与其关联的attendance记录。但是当我删除它时，我需要在SurveyQuestionResponse对象中这样做。问题是，如果我这样做，ExitSurveyResponse已被删除。有没有办法延迟删除ExitSurveyResponse s，直到家属被销毁为止？

要明确，我总是需要在attendance被销毁时更新SurveyQuestionResponse。但是SurveyQuestionResponse可以直接销毁（易于处理），销毁SurveyResponse或销毁ExitSurveyResponse时。