== CheatCodesController.rb ==

class CheatCodesController < ApplicationController
...

  # GET /cheat_codes/new
  # GET /cheat_codes/new.xml
  def new
    @cheat_code = CheatCode.new
    @cheat_code.game = Game.new

    respond_to do |format|
      format.html # new.html.erb
      format.xml  { render :xml => @cheat_code }
    end
  end

  # POST /cheat_codes
  # POST /cheat_codes.xml
  def create
    @cheat_code = CheatCode.new(params[:cheat_code])
    @cheat_code.game =  Game.new(params[:cheat_code][:game_attributes])

    respond_to do |format|
      if  @cheat_code.game.save && @cheat_code.save
        flash[:notice] = "CheatCode with game id #{@cheat_code.game.id}  was successfully created."
        format.html { redirect_to(@cheat_code) }
        format.xml  { render :xml => @cheat_code, :status => :created, :location => @cheat_code }
      else
        format.html { render :action => "new" }
        format.xml  { render :xml => @cheat_code.errors, :status => :unprocessable_entity }
      end
    end
...
end


== CheatCodes controller new.html.erb ===

<h1>New Cheat Code</h1>

<% @cheat_code.game.build %>

<% form_for(@cheat_code) do |form_cheat_code| %>
  <%= form_cheat_code.error_messages %>

   <% form_cheat_code.fields_for :game do |games_form| %>
    <p>
    <%= games_form.label :name, "Game" %><br />
    <%= games_form.text_field :name %>
    </p>
   <% end %>

  <p>
    <%= form_cheat_code.label :title %><br />
    <%= form_cheat_code.text_field :title %>
  </p>

  <p>
    <%= form_cheat_code.label :content %><br />
    <%= form_cheat_code.text_area :content, :rows => 6  %>
  </p>

  <p>
    <%= form_cheat_code.label :submitter %><br />
    <%= form_cheat_code.text_field :submitter %>
  </p>

  <p>
    <%= form_cheat_code.submit 'Create' %>
  </p>
<% end %>

<%= link_to 'Back', cheat_codes_path %>


== Game.rb Model ==

class Game < ActiveRecord::Base
	validates_presence_of :name
	belongs_to :cheat_code
end


== CheatCode.rb Model ==

class CheatCode < ActiveRecord::Base
  validates_presence_of :title, :content, :submitter
  has_one :game
  has_many :systems

   accepts_nested_attributes_for :game, :allow_destroy => :true  ,
    :reject_if => proc { |attrs| attrs.all? { |k, v| v.blank? } }

end

=== Migration ===

class CreateGames < ActiveRecord::Migration
  def self.up
    create_table :games do |t|
      t.string :name
      t.string :wikipedia

      t.timestamps
    end
  end

  def self.down
    drop_table :games
  end
end


class CreateCheatCodes < ActiveRecord::Migration
  def self.up
	create_table :cheat_codes do |t|
    t.string :title
	  t.text :content
	  t.string :submitter
	  t.integer :game_id
	  t.integer :system_id

	  t.timestamps
    end
  end

  def self.down
    drop_table :cheat_codes
  end
end

== Results ===

After creating a new CheatCode, game_id is nil should it should have been 12

#<CheatCode id: 13, title: "blah", content: "blah", submitter: "test submitter", game_id: nil, system_id: nil, created_at: "2009-05-28 23:18:05", updated_at: "2009-05-28 23:18:05">]

#<Game id: 12, name: "newgame", wikipedia: nil, created_at: "2009-05-28 23:18:05", updated_at: "2009-05-28 23:18:05">]