credit_card_type.rb

class CreditCardType < ActiveRecord::Base
  acts_as_enumeration
  
  column :display_name
  
# defaults :name => :default_name # Uses the active_record_defaults plugin
  def initialize(attributes = nil)
    super
    self.name = default_name unless attributes && attributes.include?(:name)
  end
  
  private
    def default_name
      display_name.gsub(/[^A-Za-z0-9-]/, '').underscore
    end
  
  create :id => 1, :display_name => 'Visa'
  create :id => 2, :display_name => 'Mastercard'
  create :id => 3, :display_name => 'American Express', :name => 'amex'
  create :id => 4, :display_name => 'Discover'
end