如何在使用Rails的模型中设置虚拟属性？

Question

I have a model User with usual attributes email, email_confirmation, password, password_confirmation. I use "has_secure_password" so the real attributes in the database are email and password_digest. However I would like to limit password length without spaces to 6 characters.

Here is my model :

class User < ActiveRecord::Base
  before_validation :auto_strip_confirmation
  validates :email,       presence: true,
                          length: { maximum: MAX_SIZE_DEFAULT_INPUT_TEXT },
                          format: { with: VALID_EMAIL_REGEX },
                          uniqueness: { case_sensitive: false },
                          confirmation: true
  validates :email_confirmation, presence: true
  has_secure_password
  validates :password,    length: { minimum: MIN_SIZE_USER_PASSWORD,
                                    maximum: MAX_SIZE_USER_PASSWORD }

  private

    def auto_strip_confirmation
      self.password.strip!
      self.password_confirmation.strip!
    end
end

But I get this in console :

 > user.password = user.password_confirmation = "a     "
 => "a     " 
 > user.valid?
  User Exists (0.8ms)  SELECT 1 AS one FROM "users" WHERE LOWER("users"."email") = LOWER('user@example.com') LIMIT 1
 => true 

Thanks for your help.

Answer 1

After reload, my code actually works in console : user.valid? => false (thanks surendran). But my initial problem was in my tests : I thought I could not set virtual attributes because of the error message "undefined method `strip!' for nil:NilClass". But I forgot I test if my user is valid when password is nil, nearly like this :

before { user.password = nil) }
it { should_not be_valid }

before_validation comes before this test so he tries to strip a nil object.