On 6 sep, 08:00, pipplo <[email protected]> wrote: > Hi Guys, > > I'm experimenting with my first rails app currently. One thing I'm > trying to implement is a login system. > > I created a model for user.rb I've added a couple of functions to the > class for example: > > def self.authenticate(user_info) > find_by_username_and_password(...., > self.hashed_password(user_info[:password])) > end > > def self.hashed_password(password) > Digest::SHA2.hexdigest(password) > end > > So from user.rb function self.authenticate I can call > self.hashed_password and it works fine. > > From another file (user_controller.rb) I try to create a new user > based on the authentication parameters, and then call authenticate on > that user. In order to do that I have to call > user_into.class.authenticate instead of user_info.authenticate... > > I don't understand what is going on here with def self.{function} and > the .class modifier. > > Can someone point to me somewhere to explain? I have a feeling I'm > doing something wrong but I don't understand what. > > Thanks
Hi pipplo, When you define a "def self.function" method in yor User class, you define a "class level" method. When you define a "def function" method, you define an "instance level method". Class and instance level define from where you can call a method: If its class level you need a class and thats why you call it as "User.authenticate". Given an object it needs a .class after it to obtain its class. On the other hand instance level means your method is callable from an object, so you call it as "my_user.name". Also, since you need a particular object of a class, you can't call "User.name". "self" references to the object that called the method: If you use self when defining a method, self references to the class you are defining it for. If you use self into a method's code defined at class level ( def self.method), again it references to the class (a class is also an object itself). If you use self into a method's code defined at instance level, it references to the particular object that called the method. For instance: if you call "my_user.method", "self" inside "method" would reference "my_user". -- You received this message because you are subscribed to the Google Groups "Ruby on Rails: Talk" group. To post to this group, send email to [email protected]. To unsubscribe from this group, send email to [email protected]. For more options, visit this group at http://groups.google.com/group/rubyonrails-talk?hl=en.
