dm_self_referential_friends.rb

require 'rubygems'
require 'dm-core'
require 'spec'
require 'dm_redis_adapter'
require 'dm-validations'

DataMapper::Logger.new(STDOUT, :debug)
DataMapper.setup(:default, {:adapter  => "redis"})


class User
  include DataMapper::Resource
 validates_is_unique   :name
  property :id,   Serial
  property :name, String, :unique => true

  has n, :friendships
  has n, :friends, :through => :friendships, :model => self  # XXX: model should not be necessary to specify, since it should use whatever the target_model for is Frienship.friends
end

class Friendship
  include DataMapper::Resource

  property :user_id,   Integer, :key => true
  property :friend_id, Integer, :key => true

  belongs_to :user
  belongs_to :friend, :model => User
end





@ted = User.create(:name => 'Ted')

@dan = User.create(:name => 'Dan')
User::Friendship.create(:user => @ted, :friend => @dan)
@ted.friendships
@ted.friends

@dan.friendships
@dan.friends

User.all #works

@ted = User.create(:name => 'Ted') #should not work, but does

User.all #creates error then