ruby-on-rails – ActiveSupport ::类方法的回调

2023年5月20日 158次阅读

是否可以在类方法上使用ActiveSupport :: Callbacks？更具体地说,在下面的模块中,您将在哪里放置包括ActiveSupport :: Callbacks以使define_callbacks和run_callbacks共享相同的状态？

module Handler
  extend ActiveSupport::Concern

  # If you put it here, define_callbacks is defined but run_callbacks is not
  # include ActiveSupport::Callbacks 

  included do
    class_eval do
      define_callbacks :handle
    end
  end

  module ClassMethods
    # If you put it here, run_callbacks is defined but define_callbacks is not
    # include ActiveSupport::Callbacks 

    def handle(task)
      run_callbacks :handle do
        p task
      end
    end
  end
end

class HandlerExample
  include Handler
end

更新

如果有可能,我无法确定,那肯定不是ActiveSupport :: Callbacks的设计目的.最好在#handle中创建无状态实例对象.

最佳答案 虽然整个想法有点尴尬恕我直言,你已经把define_callbacks放在错误的地方..你应该把它放在本征类中,例如

eval<< -EOF
     class<    EOF

然后你可以做“send：extend,ActiveSupport :: Callbacks”.这甚至可能有用.

但我建议您重新考虑它,并采用标准实现,在实例上调用回调.

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