Virtual attributes #3

virtual_attributes.rb

module VirtualAttributes
  extend ActiveSupport::Concern

  class VirtualAttribute
    attr_reader :name, :type
  
    def initilaize(name, type = :string)
      @name = name
      @type = type
    end
  
    def klass
      case type
      when :integer                     then Fixnum
      when :float                       then Float
      when :decimal                     then BigDecimal
      when :datetime, :timestamp, :time then Time
      when :date                        then Date
      when :text, :string, :binary      then String
      when :boolean                     then Object
      end
    end
  end

  module ClassMethods
    def attr_virtual(*attrs)
      options = attrs.extract_options!

      attrs.each do |attr|
        virtual_attributes[attr] = VirtualAttribute.new(attr, options[:type])

        class_eval do
          send("attr_accessor", attr)
        end
      end
    end
  
    def virtual_attributes
      @virtual_attributes ||= {}
    end
  end
end