了解类方法的 method_added

Question

我想在实例和类方法添加到某个类中时做一些魔法。因此我尝试了以下方法：

module Magic
  def self.included(base)
    base.extend ClassMethods
  end  
  module ClassMethods
    def method_added(name)
      puts "class method '#{name}' added"
    end  
    def some_class_method
      puts "some class method"
    end  
  end  
end

class Foo
  include Magic
  def self.method_added(name)
    puts "instance method #{name} added"
  end  
end

这种方法对于实例方法效果很好，对于类方法则失败。我该如何解决这个问题？有什么建议吗？

Answer 1

您正在寻找 singleton_method_added：

module Magic
  def self.included(base)
    base.extend ClassMethods
  end  
  module ClassMethods
    def method_added(name)
      puts "instance method '#{name}' added"
    end  

    def singleton_method_added(name)
      puts "class method '#{name}' added"
    end
  end  
end

class Foo
  include Magic

  def bla  
  end

  def blubb
  end

  def self.foobar
  end
end

输出：

instance method 'bla' added
instance method 'blubb' added
class method 'foobar' added

享受吧！