code: def validate_length(field, value, setting)
        if value.is_a?(String) || value.nil?
          result = value.nil? || (value.length < setting.first || value.length > setting.last)
          add_message(field, "incorrect value supplied for #{field.to_s} -- should be between #{setting.first} and #{setting.last} characters long.") if result
          return !result
        end
        return false
      end
docs: Validates that the length is in a given range of characters. E.g.,
  
       validate :name,   :length => 5..8