Валидация в Ruby On Rails

https://wincent.com/wiki/Validating_passwords_with_Ruby_on_Rails


например

  MINIMUM_PASSPHRASE_LENGTH     = 8
 MAXIMUM_PASSPHRASE_LENGTH     = 64

 validates_presence_of         :passphrase,
                               :on         => :create
 validates_length_of           :passphrase,
                               :in         => MINIMUM_PASSPHRASE_LENGTH..MAXIMUM_PASSPHRASE_LENGTH,
                               :if         => Proc.new { |u| !u.passphrase.blank? }
 validates_confirmation_of     :passphrase,
                               :if         => Proc.new { |u| !u.passphrase.blank? }