覆盖 ActiveRecord 属性方法 [英] Override ActiveRecord attribute methods

问题描述

我正在谈论的一个例子:

An example of what I'm talking about:

class Person < ActiveRecord::Base
  def name=(name)
    super(name.capitalize)
  end
  def name
    super().downcase  # not sure why you'd do this; this is just an example
  end
end

这似乎有效，但我刚刚阅读了 中关于覆盖属性方法的部分ActiveRecord::Base docs，它建议使用 read_attribute 和 write_attribute 方法.我认为我在上面的例子中所做的一定有问题；否则，为什么他们会祝福这些方法是覆盖属性方法的正确方法"?他们还强迫使用更丑陋的习语，所以一定有充分的理由......

This seems to work, but I was just read the section on overriding attribute methods in the ActiveRecord::Base docs, and it suggests using the read_attribute and write_attribute methods. I thought there must be something wrong with what I'm doing in the example above; otherwise, why would they bless these methods as the "right way" to override attribute methods? They're also forcing a much uglier idiom, so there must be a good reason...

我真正的问题是:这个例子有什么问题吗?

My real question: Is there something wrong with this example?

推荐答案

回应 Gareth 的评论...您的代码将无法正常工作.应该这样改写:

Echoing Gareth's comments... your code will not work as written. It should be rewritten this way:

def name=(name)
  write_attribute(:name, name.capitalize)
end

def name
  read_attribute(:name).downcase  # No test for nil?
end

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