Rails models with Single Table Inheritance and HABTM

Question

I have a project with 2 models, Game and Team. A Game has two Teams, an away team and a home team. There is a set number of Teams(no more get created) and each will belong to many Games.

I want to be able to do @game.home_team.name instead of @game.teams.find_by_id(@game.home_team_id).first.name. I'm not sure if I can do that without creating two additional models, AwayTeam and HomeTeam, which will have the same columns as Team except for an additional :game_id and maybe :type.

Currently the HABTM relationship between Games and Teams works but I have no way of turning a Team into a HomeTeam or AwayTeam once it belongs to a Game.

game.rb

class Game < ActiveRecord::Base
  has_and_belongs_to_many :teams
  has_one :away_team, -> {where(type:'away')}, class_name: 'Team' 
  has_one :home_team, -> {where(type:'home')}, class_name: 'Team'
end

team.rb

class Team < ActiveRecord::Base

  has_and_belongs_to_many :games
  # has_many :away_teams
  # has_many :home_teams
end

###

# class AwayTeam < Team
#   belongs_to :game
#   belongs_to :team
# end
# class HomeTeam < Team
#   belongs_to :game
#   belongs_to :team
# end

games_controller.rb

def create
  @game = Game.create(game_params)
  @game.teams << Team.find_all_by_id([ @game.away_team_id, @game.home_team_id ])
  @game.away_team = @game.teams.find_by_id(@game.away_team_id)
  @game.home_team = @game.teams.find_by_id(@game.home_team_id)
  @game.save
end

Any help would be really appreciated, thanks.

score 1 · Accepted Answer · answered Feb 03 '15 at 16:26

Try to add one additional model GameTeam and make has_many :through relation

  class GameTeam
    belongs_to :game
    belongs_to :team
    validates :team_type, presence: true
  end

  class Game
    has_many :game_teams
    has_may :teams, through: :game_teams
  end

Then you can make game.teams to fetch all teams. You can additionally implement scopes of methods to get home or away team by GameTeam type

Rails models with Single Table Inheritance and HABTM

1 Answers1