How would you model articles with references and citations in rails & ActiveRecord?

Question

An article has many articles that it refers to and many other articles can refer to it. Sometimes an article can refer to an article that also refers to it.

Answer 1

I'd do it like this:

class Article < ActiveRecord::Base
  # mentions in other articles
  has_many :references, :foreign_key => 'referred_article_id'
  # articles that refer to it
  has_many :referrers, :through => :references, :foreign_key => 'referred_article_id'
  # articles it refers to
  has_many :referred_articles, :through => :references, :foreign_key => 'referrer_id'
end

class Reference < ActiveRecord::Base
  belongs_to :referrer, :class => Article
  belongs_to :referred_article, :class => Article
end