ruby-on-rails - 禁用 ActiveModel 回调

Question

我发布了 an article on disabling ActiveModel callbacks ，但我不完全确定这是执行此类操作的最漂亮方法。

Mongoid::Timestamps 添加了一个更新 updated_at 字段的保存前回调。假设在某些情况下我不希望这样，并且我禁用了这样的回调:

class User
  # I'm using Mongoid, but this should work for anything based on 
  # ActiveModel.
  include Mongoid::Document
  include Mongoid::Timestamps

  def sneaky_update(attributes)
    User.skip_callback(:save, :before, :set_updated_at)
    User.update_attributes(attributes)
    User.set_callback(:save, :before, :set_updated_at)
  end

end

调用 skip_callback 然后调用 set_callback 再次设置已删除的回调是不是一个坏主意？你会怎么做？ :)

Answer 1

这个怎么样？

module Mongoid
  module Timestamps
    attr_accessor :skip_updated_at

    def set_updated_at_new
      unless self.skip_updated_at
        set_updated_at_org
      end
    end

    alias set_updated_at_org set_updated_at
    alias set_updated_at set_updated_at_new
  end
end

class User
  # I'm using Mongoid, but this should work for anything based on 
  # ActiveModel.
  include Mongoid::Document
  include Mongoid::Timestamps

  def sneaky_update(attributes)
    self.skip_updated_at = true
    User.update_attributes(attributes)
    self.skip_updated_at = false
  end

end