rails 3 mongoid和国家/地区宝石

Question

I'd like to use the countries gem I found here instead creating a separate model.

It works fine to inherit from but I'd also like to be able to have other classes belong_to it.

Is this possible? IE something like below. Is there some method I could use to provide a key to child classes?

https://github.com/hexorx/countries

class Country < ISO3166::Country
  #include Mongoid::Document    

  #RELATIONS
  has_many :cities
  has_many :reviews, as: :reviewable
end

At the moment I get NoMethodError: undefined method `has_many' for Country:Class

Or some way to include/inherit the attributes from the gem after the object is initialized?

class Country# < ISO3166::Country
  include Mongoid::Document

  #field :name, :type => String
  field :country_id, :type => String

  ##RELATIONS
  has_many :cities
  has_many :reviews, as: :reviewable


  def after_initialize
    ISO3166::Country.find_country_by_alpha3(self.country_id)
  end


end

Answer 1

对我来说，最好的行为不是在您的情况下使用has_many而是在内部使用Mongoid查询创建所需的方法。