constants to class methods

const_to_class.rb

  constants(false).reject{|symbol| symbol.to_s =~ /[a-z]/}.each do |constant|
    name = constant.to_s.downcase.gsub(/_name/, '')
    var_name = "@#{name}"
    define_singleton_method(name) do
      unless instance_variable_defined?(var_name)
        instance_variable_set(var_name, find_by(:name => const_get(constant)))
      end
      instance_variable_get(var_name)
    end
  end