ruby-on-rails – 在模型类方法上运行辅助方法

LIB / model_helper

module ModelHelper
  def method_i_want_to_use
    puts "I want to use this method"
  end
end

模型/富

class Foo < ActiveRecord::Base
    include ModelHelper
    def self.bar
      method_i_want_to_use
    end
end

此设置为我提供了无方法错误.

extend ModelHelper

include使方法可用作Foo的实例方法.这意味着,您可以在Foo的实例上调用方法method_i_want_to_use,而不是在Foo本身上调用.如果你想调用Foo本身,那么使用extend.

module ModelHelper
  def method_i_want_to_use
    puts "I want to use this method"
  end
end

class Foo
  extend ModelHelper

  def self.bar
    method_i_want_to_use
  end
end

Foo.bar
# >> I want to use this method