Devise is based on Warden (http://github.com/hassox/warden), a Rack Authentication Framework so you need to install it as a gem. Please ensure you have it installed in order to use devise (see installation below).
And you're ready to go. The generator will install an initializer which describes ALL Devise's configuration options, so be sure to take a look at it and the documentation as well:
This is a walkthrough with all steps you need to setup a devise resource, including model, migration, route files, and optional configuration. You MUST also check out the *Generators* section below to help you start.
Remember that Devise don't rely on _attr_accessible_ or _attr_protected_ inside its modules, so be sure to setup what attributes are accessible or protected in your model.
There are also some options available for configuring your routes, as :class_name (to set the class for that route), :path_prefix, :as and :path_names, where the last two have the same meaning as in common routes. The available :path_names are:
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:
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. This means that you need to set the root inside your routes:
Finally, you also need to setup default url options for the mailer in each environment. Here's is the configuration for config/environments/development.rb:
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 just authentication, trackable, lockable and timeoutable stuff and none of confirmation or password recovery. Just follow the same steps:
A model configured with all devise modules and attr_accessible for default fields will be created. The generator will also create the migration and configure your routes for devise.
The devise method in your models also accept some options to configure its modules. For example, you can chose which encryptor to use in authenticatable:
Besides :encryptor, you can provide :pepper, :stretches, :confirm_within, :remember_for, :timeout_in, :unlock_in and others. All those are describer in the initializer created when you invoke the devise_install generator describer above.
Since devise is an engine, it has all default views inside the gem. They are good to get you started, but you will want to customize them at some point. And Devise has a generator to make copy them all to your application:
By default Devise will use the same views for all roles you have. But what if you need so different views to each of them? Devise also has an easy way to accomplish it: just setup config.scoped_views to true inside "config/initializers/devise.rb".
After doing so you will be able to have views based on the scope like 'sessions/users/new' and 'sessions/admin/new'. If no view is found within the scope, Devise will fallback to the default view.
Devise includes some tests helpers for functional specs. To use them, you just need to include Devise::TestHelpers in your test class and use the sign_in and sign_out method. Such methods have the same signature as in controllers:
You can include the Devise Test Helpers in all of your tests by adding the following to the bottom of your test/test_helper.rb or spec/spec_helper.rb file:
Do not use such helpers for integration tests like Cucumber, Webrat... Just fill in the form or explicitly set the user in session. For more tips, check the wiki (http://wiki.github.com/plataformatec/devise).
Devise implements encryption strategies for Clearance, Authlogic and Restful-Authentication. To make use of it set the desired encryptor in the encryptor initializer config option. You might also need to rename your encrypted password and salt columns to match Devises's one (encrypted_password and password_salt).
Devise supports both ActiveRecord (default) and MongoMapper, and has experimental Datamapper supports (in a sense that Devise test suite does not run completely with Datamapper). To choose other ORM, you just need to configure it in the initializer file.