Question

我有一个ActiveRecord课程约会：

class Appointment < ActiveRecord::Base
  after_save :send_notifications
  before_destroy :send_notifications

  protected:

  def send_notifications
    if destroyed?
      logger.info "Destroyed"
    else
      logger.info "Confirmed"
    end
  end
end

现在的问题是我正在试图找到一种方法来确定哪个回调负责触发send_notification？ after_save或before_destroy？无论如何要知道如果被摧毁了怎么样？我用这里示范？

提前致谢

Eki

Answer 1

如果您想在两个回调中使用不同的行为，我建议您通过单独的方法进行调度：

class Appointment < ActiveRecord::Base
  after_save :send_notifications_on_save
  before_destroy :send_notifications_on_destroy

  protected

  def send_notifications_on_save
    send_notifications('Confirmed')
  end

  def send_notifications_on_destroy
    send_notifications('Destroyed')
  end

  def send_notifications(message)
    logger.info message
  end
end

Answer 2

我不确定在这个阶段您是否可以告诉您是要破坏还是保存对象。

您可以略微不同地调用回调以捕获该信息。例如：

after_save do |appointment| 
  appointment.send_notifications(:saving)
end
before_destroy do |appointment| 
  appointment.send_notifications(:destroying)
end

protected

def send_notifications(because)
  if because == :destroying
    log.info("Destroyed")
  else
    log.info("Confirmed")
  end
end

确定哪个回调负责在Rails中触发事件？ after_save或before_destroy触发了回调？

2 个答案: