Ruby 在模块方法内访问类变量

鉴于以下情况：

module RESTable
  BASE_URL  = "http://url.domain/api/rest"
  LOGIN_URL = "#{BASE_URL}/login"
  LOGOUT_URL = "#{BASE_URL}/logout"

  def request_url
    "#{BASE_URL}/mbo/#{@@object_resource}/_format=json"
  rescue NameError
    p "@@object_resource was not defined"
  end
end

class ServiceRequests
  include RESTable
  @@object_resource = "sr"

  def initialize
    binding.pry
  end
end

在pry会话中，调用request_url会产生：

"@@object_resource was not defined"

但是@@object\u资源被设置为“sr”

其思想是，对于每个类，我只需包含可重启模块，调用request\u url将根据我所包含的类的@object\u资源为我提供正确的url

---

更一般地说，如何从模块内调用类变量？

我通过在模块上声明@@object\u资源解决了这个问题，然后如果@@object\u资源未更改（即为空），则会引发一个错误

以下是更新的模块：

module RESTable
  BASE_URL  = "http://url.domain/api/rest"
  LOGIN_URL = "#{BASE_URL}/login"
  LOGOUT_URL = "#{BASE_URL}/logout"
  @@object_resource = ""

  def request_url
    raise StandardError, "@@object_resource can't be blank" if @@object_resource == ""
    "#{BASE_URL}/mbo/#{@@object_resource}/_format=json"
  rescue NameError
    p "@@object_resource was not defined"
  end
end