Question

我有一个名为Message的模型。我有一个名为time_received_or_sent的字段存储在数据库中。传入的消息将具有time_recieved，并且传出的消息将发送时间。没有任何信息可以同时拥有。我可以在模型中组合这些，以便time_received和time_sent在编辑时只指向该字段吗？我的模型中有四种方法看起来很无用。

  Model Message < ActiveRecord::Base
  ...
    def time_received=(time_received)
      time_received_or_sent = time_received
    end

    def time_received
      return time_received_or_sent
    end

    def time_sent=(time_sent)
      time_received_or_sent = time_sent
    end

    def time_sent
      return time_received_or_sent
    end
  end

我希望更短的东西。

我正在寻找除了以外的东西：

def time_sent; time_received_or_sent; end
def time_received; time_received_or_sent; end
def time_sent=(time_sent); time_received_or_sent=(time_sent); end
def time_received=(time_received); time_received_or_sent=(time_received); end

虽然，如果这是最好的，那我就没事了。

Answer 1

Model Message < ActiveRecord::Base
...
  alias_attribute :time_sent, :time_received_or_sent
  alias_attribute :time_received: time_received_or_sent
end

Answer 2

您始终可以使用alias_method将其折叠：

class Message < ActiveRecord::Base
  def time_received=(time_received)
    time_received_or_sent = time_received
  end
  alias_method :time_sent=, :time_received=

  def time_received
    time_received_or_sent
  end
  alias_method :time_sent, :time_received
end

这对于避免重复实现相同方法非常方便。

如何简化折叠到rails中相同字段的模型中的属性？

2 个答案: