Rails many-to-many same class bi-directional relationship.. how?

So heres the deal.. i'm writing a rails application to manage contact data..

I have a contact model and that contact needs to have many family members (still the contact class).. that relationship needs associated relationship data.. ie

ContactA | ContactB | Relationship
1          2          Contact A is Contact B's Father

How can i relate 2 objects of the same class and attach some data and be able to traverse te relationship bidirectionally like so:

@guy1 = Contact.find(1) #Guy A
@guy1.family_relationships
>开发者_开发问答>> [[guyb, "f"], [guyc, "s"]]
@guy2 = @guy1.family_members.first
@guy1.family_members
>>> [[guya]]

Thats probably not 100% correct but its late and ive been battling with a server all day so please forgive me!!

I've heard you have to do all kinds of hacky SQL to do it..

Thanks!

Daniel

---

I had a similar situation in one of my projects earlier. I went with the following design:

class Patient < AR::Base
  has_many :relatives, :dependent => :destroy do
    def husband
      select { |r| r.relation.eql?('Husband').first
    end

    def father
      select { |r| r.relation.eql?('Father').first
    end

    ... 

    def sons
      select { |r| r.relation.eql?('Son')
    end
    ...
  end
end

class Relative < AR::Base
  belongs_to :patient

  validates :relation, 
    :inclusion => { 
      :in => %w( Husband Daughter Son Father Mother Brother Sister )
    }
end

This works for me. Hope this helps you or at least point you in the right direction!

---

Thanks for the great answers but found the answer here:

http://railscasts.com/episodes/163-self-referential-association

Railscasts is awesome!