ruby-on-rails - 将 Ohm 模型树转换为 JSON 结构

Question

我有一棵欧姆模型树。游戏有玩家，玩家有棋子。完整的细节如下。基本上，当我将结构呈现为 json 时，我看到一个编码错误:

NoMethodError (undefined method `encode_json' for #Piece:0x00000102b8dbb8):

但是，我可以毫无错误地输出 Player 和他们的 Pieces。

Player = Player.create(:name => "Toby")
game.player << player 

player.pieces << Piece.create(:name => "Rook")

# works fine 
logger.debug(player.to_hash.to_json)

# FAILS with the above error
logger.debug(game.to_hash.to_json)    

我最好的猜测是集合的嵌套中有什么东西导致了这里的问题。

有什么想法吗？

class Game < Ohm::Model
  collection :player, Player  

  def to_hash
    super.merge(:players => players)
  end
end


class Player < Ohm::Model
  reference :game, Game
  collection :pieces, Piece

  attribute :name  

  def to_hash
    super.merge(:name => name, :pieces => pieces)
  end
end


class Piece < Ohm::Model
  reference :player, Player

  def to_hash
    super.merge(:name => name)
  end    
end

Answer 1

我发现这可以解决问题:

class Player < Ohm::Model
  def to_hash
    super.merge(:name => name, :pieces => pieces.all)
  end
end