Simple symbolized accessor for Active Record

core_extensions.rb

class String
  def articleize
    %w(a e i o u).include?(self[0].downcase) ? "an #{self}" : "a #{self}"
  end
end

symbolized_accessor.rb

# Usage
# symbolize :status, in: [ :complete, :on_track, :working, :on_hold ]
# symbolize :benchmark_type, in: [ :none, :national, :custom ], allow_nil: true

module SymbolizedAccessor
  extend ActiveSupport::Concern

  class_methods do

    def symbolize(attr_name, config = {})
      # define attribute reader
      define_method(attr_name.to_s) { read_attribute(attr_name).try(:to_sym) }
      # define validator
      validates attr_name, inclusion: { in: config[:in] }, allow_nil: true
      validates(attr_name, presence: { message: "select #{attr_name.to_s.humanize.downcase.articleize}" }) unless config[:allow_nil]
    end
  end
end

ActiveRecord::Base.send(:include, SymbolizedAccessor)