Rails模型验证更新

Question

I cannot figure out why my model is not behaving as I want.

 class User < ActiveRecord::Base
    has_secure_password
    validates :first_name, :last_name, 
               presence:true, 
               length: { maximum: 30 }
    validates :username, 
              presence:true, 
              uniqueness:true, 
              length: { maximum: 30 }
    validates :password, 
               presence:true, 
               confirmation: true, 
               length: { :minimum => 6}, 
               unless: lambda{ persisted? and password.nil? }
    validates :password_confirmation, 
               presence: true, 
               unless: lambda{ persisted? and password.nil? }
    validates :email, 
               format: { with: /\A([^@\s]+)@((?:[-a-z0-9]+\.)+[a-z]{2,})\z/i, on: :create }, 
               uniqueness: true, 
               allow_blank: true
 end

As you can see the code is quite easy.

To have a password_digest field I neeed both 'password' and 'password_confirmation'.

In create mode everything is fine. In update mode is not working as I need.

I want to check validate the password and check if they match always, except when the user already exist and the 'password' field is null.

Any suggestion?

Answer 1

I would try a simpler logic:

validates :password, 
          presence:true, 
          confirmation: true, 
          length: { :minimum => 6}, 
          unless: :persisted?

validates :password_confirmation, 
          presence: true, 
          if: lambda{ password.present? }

For a new User :

• if password is blank, you get an error on password
• if password is present and password_confirmation is blank, you get an error on password_confirmation

For an existing User :

• if password is blank, nothing happens
• if password is present and password_confirmation is blank, you get an error on password_confirmation