rails魔术字段的实现 ,alias_method_chain用法,for classmethod
阅读更多Encapsulatesthecommonpatternof:alias_method:foo_without_feature,:fooalias_method:foo,:foo_with_featureWiththis,yousimplydo:alias_method_chain:foo,:feature替我们定义了两个方法:foo_with_feature和foo_without_fe