gistfile1.txt

class GameMode
  include DataMapper::Resource

  property :id, Serial
  property :title, String
  property :description, Text
  property :max_players, Integer
  
  has n, :game_mode_types
  has n, :game_mode_matches
  has n, :parents, :through => :game_mode_matches, :class_name => 'GameMode',
                       :remote_name => :parent, :child_key => [:parent_id]
  has n, :children, :through => :game_mode_matches, :class_name => 'GameMode',
                         :remote_name => :child, :child_key => [:child_id]
  
  belongs_to :game
end

class GameModeMatch
  include DataMapper::Resource
  
  property :parent_id, Integer, :key => true
  property :child_id, Integer, :key => true
  
  belongs_to :parent, :class_name => 'GameMode', :child_key => [:parent_id]
  belongs_to :child, :class_name => 'GameMode', :child_key => [:child_id] 
  
end