红宝石混入与类方法，实例方法和类变量

Question

你知道如何定义@@method_names类变量，这样既my_macro和invoke_methods可以使用它作为故意的吗？谢谢！

module MyModule 

    module ClassMethods  
     def my_macro method_name, options = { } 
      define_method method_name do 
       puts "defining #{method_name} with #{options}" 
      end 
      @@method_names << method_name 
     end  
    end 

    def invoke_methods 
     @@method_names.each { |method_name| send method_name } 
    end 

    def self.included includer 
     includer.extend ClassMethods 
    end 

end 

class MyClass 
    include MyModule 
    my_macro :method_foo, :bar => 5 
    my_macro :method_baz, :wee => [3,4] 
end 

MyClass.new.invoke_methods 

Answer 1

这里有一个工作版本。变化被注释：

module MyModule 
    module ClassMethods 
     @@method_names ||= [] #move this up here 
     def my_macro method_name, options = { } 
      define_method method_name do 
       puts "defining #{method_name} with #{options}" 
      end 
      @@method_names << method_name 
     end 

     #added this (rename as required) 
     def the_methods 
      @@method_names 
     end 
    end 

    def invoke_methods 
     #changed this call 
     self.class.the_methods.each { |method_name| send method_name } 
    end 

    def self.included includer 
     includer.extend ClassMethods 
    end 
end 

class MyClass 
    include MyModule 
    my_macro :method_foo, :bar => 5 
    my_macro :method_baz, :wee => [3,4] 
end 

MyClass.new.invoke_methods 

Answer 2

module MyModule 

    module ClassMethods  
     def my_macro method_name, options = { } 
      define_method method_name do 
       puts "defining #{method_name} with #{options}" 
      end 
      @method_names ||= [] 
      @method_names << method_name 
     end 

     def method_names 
      @method_names 
     end 
    end 

    def invoke_methods 
     self.class.method_names.each { |method_name| send method_name } 
    end 

    def self.included includer 
     includer.extend ClassMethods 
    end 

end 

class MyClass 
    include MyModule 
    my_macro :method_foo, :bar => 5 
    my_macro :method_baz, :wee => [3,4] 
end 

MyClass.new.invoke_methods