使用Ruby中的类方法在模块中定义的方法

I have a small problem that I can't quite get my head around. Since I want to reuse a lot of the methods defined in my Class i decided to put them into an Helper, which I can easily include whenever needed. The basic Class looks like this:

我有一个小问题，我无法理解。由于我想重用我的类中定义的许多方法，我决定将它们放入Helper中，我可以随时轻松地将其包含在内。基本类看起来像这样：

class MyClass
  include Helper::MyHelper
  def self.do_something input
    helper_method(input)
  end
end

And here is the Helper:

这是助手：

  module Helper
    module MyHelper
      def helper_method input
        input.titleize
      end
    end
  end

Right now I can't call "helper_method" from my Class because of what I think is a scope issue? What am I doing wrong?

现在我不能从我的班级调用“helper_method”因为我认为是范围问题？我究竟做错了什么？

1 个解决方案

#1

I guess that is because self pointer inside of do_something input is InternshipInputFormatter, and not the instance of InternshipInputFormatter. so proper alias to call helper_method(input) will be self.helper_method(input), however you have included the Helper::MyHelper into the InternshipInputFormatter class as an instance methods, not a singleton, so try to extend the class with the instance methods of the module as the signelton methods for the class:

我想这是因为do_something输入中的自指针是InternshipInputFormatter，而不是InternshipInputFormatter的实例。所以调用helper_method（输入）的正确别名将是self.helper_method（输入），但是你已经将Helper :: MyHelper作为实例方法包含在InternshipInputFormatter类中，而不是单例，所以尝试使用实例方法扩展类该模块作为该类的signelton方法：

class InternshipInputFormatter
   extend Helper::MyHelper
   def self.do_something input
      helper_method(input)
   end
end 

InternshipInputFormatter.do_something 1
# NoMethodError: undefined method `titleize' for 1:Fixnum

As you can see, the call has stopped the execution inside the helper_method. Please refer to the document to see the detailed difference between include, and extend.

如您所见，调用已停止helper_method内的执行。请参阅文档以查看include和extend之间的详细区别。