:inclusion validator

inclusion.rb

class Resource < ActiveRecord::Base
  module Types
    ACTIVE    = 'active'
    CANCELLED = 'cancelled'
    CEASED    = 'ceased'
    DITCHED   = 'ditched'
    MEDIA     = 'media'
    ONE_TIME  = 'one time'
    ARCHIVED  = 'archived'
  end

  RESOURCE_TYPES = [Types::ACTIVE, Types::CANCELLED, Types::CEASED, Types::DITCHED, 
                    Types::MEDIA, Types::ONE_TIME, Types::ARCHIVED]

  validates :resource_type, :inclusion => { :in => RESOURCE_TYPES, 
                                            :message => "%{value} is not a valid resource type value" }
  ...
  ...
end