== Devise

Devise is a flexible authentication solution for Rails based on Warden. It:

* Is Rack based;
* Is a complete MVC solution based on Rails engines;
* Allows you to have multiple roles (or models/scopes) signed in at the same time;
* Is based on a modularity concept: use just what you really need.

Right now it's composed of four mainly modules:

* Authenticable: responsible for encrypting password and validating authenticity of a user while signing in.
* Confirmable: responsible for verifying whether an account is already confirmed to sign in, and to send emails with confirmation instructions.
* Recoverable: takes care of reseting the user password and send reset instructions.
* Validatable: creates all needed validations for email and password. It's totally optional, so you're able to to customize validations by yourself.

== Dependencies

Devise is based on Warden (http://github.com/hassox/warden), a Rack Authentication Framework so you need to install it as a gem. Current warden version is 0.4.0. Please ensure you have it installed in order to use devise (see instalation below).

== Installation

Install warden gem if you don't have it installed:

  sudo gem install warden

Install devise as an engine (plugin) inside your app:

  script/plugin install git://github.com/plataformatec/devise.git

And you're ready to go.

== Basic Usage

Devise must be setted up within the model (or models) you want to use, and devise routes must be created inside your routes.rb file.

We're assuming here you want a User model. First of all you have to setup a migration with the following fields:

  # required
  t.string :email,              :null => false
  t.string :encrypted_password, :null => false
  t.string :password_salt,      :null => false

  # required for confirmable
  t.string   :confirmation_token
  t.datetime :confirmation_sent_at
  t.datetime :confirmed_at

  # required for recoverable
  t.string   :reset_password_token

Now let's setup a User model adding the devise line to have your authentication working:

  class User < ActiveRecord::Base
    devise
  end

This line adds devise authenticable automatically for you inside your User class. You could also include the other modules as below:

  # Same as using only devise, authenticable is activated by default
  devise :authenticable

  # Include authenticable + confirmable
  devise :confirmable

  # Include authenticable + recoverable
  devise :recoverable

  # Include authenticable + confirmable + recoverable + validatable
  devise :confirmable, :recoverable, :validatable

  # Same as above, include all of them
  devise :all

  # Include all except recoverable
  devise :all, :except => :recoverable

Note that validations aren't added by default, so you're able to customize it. In order to have automatic validations working just include :validatable.

The next step after setting up your model is to configure your routes for devise. You do this by opening up your config/routes.rb and adding:

  map.devise_for :users

This is going to look inside you User model and create the needed routes:

  # Session routes for Authenticable (default)
       new_user_session GET  /users/sign_in                    {:controller=>"sessions", :action=>"new"}
           user_session POST /users/sign_in                    {:controller=>"sessions", :action=>"create"}
   destroy_user_session GET  /users/sign_out                   {:controller=>"sessions", :action=>"destroy"}

  # Password routes for Recoverable, if User model has :recoverable configured
      new_user_password GET  /users/password/new(.:format)     {:controller=>"passwords", :action=>"new"}
     edit_user_password GET  /users/password/edit(.:format)    {:controller=>"passwords", :action=>"edit"}
          user_password PUT  /users/password(.:format)         {:controller=>"passwords", :action=>"update"}
                        POST /users/password(.:format)         {:controller=>"passwords", :action=>"create"}

  # Confirmation routes for Confirmable, if User model has :confirmable configured
  new_user_confirmation GET  /users/confirmation/new(.:format) {:controller=>"confirmations", :action=>"new"}
      user_confirmation GET  /users/confirmation(.:format)     {:controller=>"confirmations", :action=>"show"}
                        POST /users/confirmation(.:format)     {:controller=>"confirmations", :action=>"create"}

You can run the routes rake task to verify what routes are being created by devise.
There are also some options available for configuring your routes:

* :class_name => setup a different class to be looked up by devise, if it cannot be correctly find by the route name.

  map.devise_for :users, :class_name => 'Account'

* :as => allows you to setup path name that will be used, as rails routes does. The following route configuration would setup your route as /accounts instead of /users:

  map.devise_for :users, :as => 'accounts'

* :singular => setup the name used to create named routes. By default, for a :users key, it is going to be the singularized version, :user. To configure a named route like account_session_path instead of user_session_path just do:

  map.devise_for :users, :singular => :account

* :path_names => configure different path names to overwrite defaults :sign_in, :sign_out, :password and :confirmation.

  map.devise_for :users, :path_names => { :sign_in => 'login', :sign_out => 'logout', :password => 'secret', :confirmation => 'verification' }

And that is it! Devise is gonna create some helpers to use inside your controllers and views. To setup a controller that needs user authentication, just add this before_filter:

  before_filter :authenticate_user!

To verify if a user is signed in, you have the following helper:

  user_signed_in?

And to get the current signed in user this helper is available:

  current_user

You have also access to the session for this scope:

  user_session

After signing in a user, confirming it's account or updating it's password, devise will look for a scoped root path to redirect. Example: For a :user resource, it will use user_root_path if it exists, otherwise default root_path will be used.

Devise let's you setup as many roles as you want, so let's say you already have this User model and also want an Admin model with the same authentication stuff, but not confirmation or password recovery. Just follow the same steps:

  # Create a migration with the required fields
  t.string :email,              :null => false
  t.string :encrypted_password, :null => false
  t.string :password_salt,      :null => false

  # Inside your Admin model
  devise :validatable

  # Inside your routes
  map.devise_for :admin

  # Inside your protected controller
  before_filter :authenticate_admin!

  # Inside your controllers and views
  admin_signed_in?
  current_admin
  admin_session

== TODO

Please refer to TODO file.

== Bugs and Feedback

If you discover any bugs or want to drop a line, feel free to create an issue.

MIT License. Copyright 2009 Plataforma Tecnologia. http://blog.plataformatec.com.br