ruby - Rails Tutorial : 6.3.1 An encrypted password -

i going though tutorial (which must excellent resource) , don't quite understand following:

in section 6.3.1 create password_digest column in db via creating , running migration script via :

rails generate migration add_password_digest_to_users password_digest:string bundle exec rake db:migrate bundle exec rake db:test:prepare bundle exec rspec spec/ 

then on rails console able instantiate user model object , set password_digest on :

irb(main):007:0> @user = user.new => #<user id: nil, name: nil, email: nil, created_at: nil, updated_at: nil,     password_digest: nil> irb(main):008:0> @user.password_digest = "zzzz" => "zzzz" irb(main):009:0> @user.password_digest => "zzzz"    

however can not see password_digest property on user model class definition :

class user < activerecord::base   attr_accessible :email, :name    before_save { |user| user.email = email.downcase}    valid_email_regex = /\a[\w+\-.]+@[a-z\d\-.]+\.[a-z]+\z/i    validates :name, presence: true, length: {maximum: 50}   validates :email, presence: true, format: { with: valid_email_regex}, uniqueness: {case_sensitive: false} end 

i imagine rails doing magic under covers, mind explaining it's doing?

thanks!

you right - what's going on here is rails magic behind scenes.

whenever have descendant of activerecord::base activerecord @ database table class , automatically create accessors - won't show in class definition. seems crazy if you're coming language c# had kind of stuff manually before.

what activerecord doing (this very watered down explanation, actual thing more complicated) kind of sticking following code in class:

class user < activerecord::base   def password_digest     @password_digest   end    def password_digest=(val)     @password_digest = val   end  end 

the other thing note doesn't creation of attribute getter , setter - mixes in type casting based on type of column. check out this question more info , possible gotchas.

the net result of kind of bonus, , 1 of reasons rails: define column once in database, , put model class free.

this pattern common rails though, , you'll see often. if still learning ruby or rails framework , aren't 100% sure comes from, don't afraid more closely - so-called rails 'magic' occurs , takes time not surprised. had experience when first moved rails other languages.