active_enum.rb

class ActiveEnumValue < Object 
 
  attr_reader :to_s 

  def initialize(option)
    @to_s = option.to_s.downcase 
  end

end

module ActiveEnum
    
  module ClassMethods
      
    def new(option)
      self::OPTION_HASH[option] || TypeError.new("Valid options are #{self.valid_options}")
    end
    
    def all
      self::OPTIONS.map {|e| self.new(e) }
    end
    
    def valid_options
      self::OPTIONS.map(&:to_s).join(', ')
    end
  
  end
  
  def self.included(other)
    other.extend ClassMethods
    
    other.const_set("OPTION_HASH", Hash.new)

    other::OPTIONS.each do |option|
      klass = Class.new(ActiveEnumValue)

      Object.const_set("#{other}#{option.to_s.camelize}", klass)
    
      instance = klass.new(option)
      
      other::OPTION_HASH[option] = instance
      other::OPTION_HASH[option.to_s.downcase] = instance
      
      ActiveEnum.const_set(option.to_s.upcase, instance)
    end

  end
  
end

active_enum_attributes.rb

# Use in active record classes where you want to create a method that returns an ActiveEnum object

# Example 1 - method and class are the same:
# active_enum_attr :priority
# 
# Example 2 - method and class are different
# active_enum_attr :class_name, :method_name

module ActiveEnumAttributes
  module ClassMethods
    def active_enum_attr(klass, method=nil)
      
      method ||= klass
      
      self.instance_eval do
        
        # Define getter method
        define_method method do
          klass.to_s.camelize.constantize.new super
        end
        
        # Define setter method
        define_method "#{method}=" do |value|
          super value.to_s
        end
        
      end
      
    end
  end
  
  def self.included(other)
    other.extend ClassMethods
  end
  
end