serialize'd array not unserializing properly

I don't have time to make a patch for this, but I wanted to bring it to everyone's attention.

Take this code as an example

class Peg
  # does not inherit from ActiveRecord
  def some_method
     "foo"
  end
end

class Board < ActiveRecord::Base
  serialize :pegs
  def setup_pegs
    self.pegs = [Peg.new, Peg.new, Peg.new]
  end
end

class SomeController < ApplicationController
  def index
    b = find_or_create_board
    b.pegs[0].some_method  # IMPORTANT LINE!
  end
  
  def find_or_create_board
    b = Board.find(:first)
    if b.nil?
      b = Board.new
      b.setup_pegs
      b.save!
      b
    end
  end
end

This code will work fine the first time though because it creates new Peg objects. The second time through, when it has to load the pegs from the database, the "b.pegs[0].some_method" will result in a NoMethodError because the "pegs" array actually looks (something) like this:

"#<YAML::Object:0x52cc220 @ivars={}, @class="Peg">",

"#<YAML::Object:0x52cc220 @ivars={}, @class="Peg">",

"#<YAML::Object:0x52cc220 @ivars={}, @class="Peg">"

It is an array of YAML objects instead of an array of Pegs, therefor, it doesn't have "some_method" like you would expect. I learned form this helpful blog that adding

require 'peg'

to the top of the Board class will solve this problem. The reason it is happening is because the YAML loading method can't find the Peg class and defaults to making it a YAML object.