UUIDPrimaryKey
==============

Copyright 2006-2007, Chris Hapgood
MIT License
Derived from the works of several others, including Demetrio Nunes, Paul Dix and Lee Jensen.

Requirements: UUIDTools GEM (gem install uuidtools)

In any model class requiring a UUID PK, invoke UUIDPrimaryKey, optionally with 
the name of the PK column in your database.  Example: 

  class Person < ActiveRecord::Base
  	UUIDPrimaryKey
  end
  
  class Place < ActiveRecord::Base
    UUIDPrimaryKey :column => 'uuid'
  end
 
Hints:
  1. To override the value of the PK from the application, define an 
  initialize method in your model like this:
   class Person < ActiveRecord::Base
     UUIDPrimaryKey :column => 'uuid'
    
     def initialize(params = nil)
       super
       self.id = params[:uuid] unless params[:uuid].nil?
     end
   end
  
  2. To define a reasonable colum using migrations, try this:
   class AddPeople < ActiveRecord::Migration
     def self.up
       create_table :people, :id => false do |t|
         t.column :uuid, :string, :limit => 36
         t.column :firstnames, :string, :limit => 55
         t.column :lastname, :string, :limit => 35
         t.column :created_at, :timestamp
         t.column :updated_at, :timestamp
       end
         execute("ALTER TABLE people ADD PRIMARY KEY(uuid)")
     end
   
     def self.down
       drop_table :people
     end
   end