Devise - a flexible authentication solution

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 models signed in at the same time;

Is based on a modularity concept: use only what you really need.

It's composed of 10 modules:

Database Authenticatable: hashes and stores a password in the database to validate the authenticity of a user while signing in. The authentication can be done both through POST requests or HTTP Basic Authentication.

Omniauthable: adds OmniAuth (https://github.com/omniauth/omniauth) support.

Confirmable: sends emails with confirmation instructions and verifies whether an account is already confirmed during sign in.

Recoverable: resets the user password and sends reset instructions.

Registerable: handles signing up users through a registration process, also allowing them to edit and destroy their account.

Rememberable: manages generating and clearing a token for remembering the user from a saved cookie.

Trackable: tracks sign in count, timestamps and IP address.

Timeoutable: expires sessions that have not been active in a specified period of time.

Validatable: provides validations of email and password. It's optional and can be customized, so you're able to define your own validations.

Lockable: locks an account after a specified number of failed sign-in attempts. Can unlock via email or after a specified time period.

Getting started

Devise 4.0 works with Rails 4.1 onwards. Add the following line to your Gemfile:


gem 'devise'

Then run bundle install

Next, you need to run the generator:


$ rails generate devise:install

At this point, a number of instructions will appear in the console. Among these instructions, you'll need to set up the default URL options for the Devise mailer in each environment. Here is a possible configuration for config/environments/development.rb:


config.action_mailer.default_url_options = { host: 'localhost', port: 3000 }

The generator will install an initializer which describes ALL of Devise's configuration options. It is imperative that you take a look at it. When you are done, you are ready to add Devise to any of your models using the generator.

In the following command you will replace MODEL with the class name used for the application’s users (it’s frequently User but could also be Admin). This will create a model (if one does not exist) and configure it with the default Devise modules. The generator also configures your config/routes.rb file to point to the Devise controller.


$ rails generate devise MODEL

Next, check the MODEL for any additional configuration options you might want to add, such as confirmable or lockable. If you add an option, be sure to inspect the migration file (created by the generator if your ORM supports them) and uncomment the appropriate section. For example, if you add the confirmable option in the model, you'll need to uncomment the Confirmable section in the migration.

Then run rails db:migrate

You should restart your application after changing Devise's configuration options (this includes stopping spring). Otherwise, you will run into strange errors, for example, users being unable to login and route helpers being undefined.

Controller filters and helpers

Devise will create some helpers to use inside your controllers and views. To set up a controller with user authentication, just add this before_action (assuming your devise model is 'User'):

before_action :authenticate_user!

For Rails 5, note that protect_from_forgery is no longer prepended to the before_action chain, so if you have set authenticate_user before protect_from_forgery, your request will result in "Can't verify CSRF token authenticity." To resolve this, either change the order in which you call them, or use protect_from_forgery prepend: true.

If your devise model is something other than User, replace "_user" with "_yourmodel". The same logic applies to the instructions below.

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


user_signed_in?

For the current signed-in user, this helper is available:


current_user

You can access the session for this scope:


user_session

After signing in a user, confirming the account or updating the password, Devise will look for a scoped root path to redirect to. For instance, when using a :user resource, the user_root_path will be used if it exists; otherwise, the default root_path will be used. This means that you need to set the root inside your routes:

root to: 'home#index'

You can also override after_sign_in_path_for and after_sign_out_path_for to customize your redirect hooks.

Notice that if your Devise model is called Member instead of User, for example, then the helpers available are:


before_action :authenticate_member!

member_signed_in?

current_member

member_session

Configuring Models

The Devise method in your models also accepts some options to configure its modules. For example, you can choose the cost of the hashing algorithm with:

devise :database_authenticatable, :registerable, :confirmable, :recoverable, stretches: 13

Besides :stretches, you can define :pepper, :encryptor, :confirm_within, :remember_for, :timeout_in, :unlock_in among other options. For more details, see the initializer file that was created when you invoked the "devise:install" generator described above. This file is usually located at /config/initializers/devise.rb.

Strong Parameters

The Parameter Sanitizer API has changed for Devise 4 ⚠️

For previous Devise versions see https://github.com/heartcombo/devise/tree/3-stable#strong-parameters

When you customize your own views, you may end up adding new attributes to forms. Rails 4 moved the parameter sanitization from the model to the controller, causing Devise to handle this concern at the controller as well.

There are just three actions in Devise that allow any set of parameters to be passed down to the model, therefore requiring sanitization. Their names and default permitted parameters are:

sign_in (Devise::SessionsController#create) - Permits only the authentication keys (like email)

sign_up (Devise::RegistrationsController#create) - Permits authentication keys plus password and password_confirmation

account_update (Devise::RegistrationsController#update) - Permits authentication keys plus password, password_confirmation and current_password

In case you want to permit additional parameters (the lazy way™), you can do so using a simple before action in your ApplicationController:


class ApplicationController < ActionController::Base
  before_action :configure_permitted_parameters, if: :devise_controller?

  protected

  def configure_permitted_parameters
    devise_parameter_sanitizer.permit(:sign_up, keys: [:username])
  end
end

The above works for any additional fields where the parameters are simple scalar types. If you have nested attributes (say you're using accepts_nested_attributes_for), then you will need to tell devise about those nestings and types:


class ApplicationController < ActionController::Base
  before_action :configure_permitted_parameters, if: :devise_controller?

  protected

  def configure_permitted_parameters
    devise_parameter_sanitizer.permit(:sign_up, keys: [:first_name, :last_name, address_attributes: [:country, :state, :city, :area, :postal_code]])
  end
end

Devise allows you to completely change Devise defaults or invoke custom behavior by passing a block:

To permit simple scalar values for username and email, use this


def configure_permitted_parameters
  devise_parameter_sanitizer.permit(:sign_in) do |user_params|
    user_params.permit(:username, :email)
  end
end

If you have some checkboxes that express the roles a user may take on registration, the browser will send those selected checkboxes as an array. An array is not one of Strong Parameters' permitted scalars, so we need to configure Devise in the following way:


def configure_permitted_parameters
  devise_parameter_sanitizer.permit(:sign_up) do |user_params|
    user_params.permit({ roles: [] }, :email, :password, :password_confirmation)
  end
end

For the list of permitted scalars, and how to declare permitted keys in nested hashes and arrays, see

https://github.com/rails/strong_parameters#nested-parameters

If you have multiple Devise models, you may want to set up a different parameter sanitizer per model. In this case, we recommend inheriting from Devise::ParameterSanitizer and adding your own logic:


class User::ParameterSanitizer < Devise::ParameterSanitizer
  def initialize(*)
    super
    permit(:sign_up, keys: [:username, :email])
  end
end

And then configure your controllers to use it:


class ApplicationController < ActionController::Base
  protected

  def devise_parameter_sanitizer
    if resource_class == User
      User::ParameterSanitizer.new(User, :user, params)
    else
      super # Use the default one
    end
  end
end

The example above overrides the permitted parameters for the user to be both :username and :email. The non-lazy way to configure parameters would be by defining the before filter above in a custom controller. We detail how to configure and customize controllers in some sections below.

Configuring views

We built Devise to help you quickly develop an application that uses authentication. However, we don't want to be in your way when you need to customize it.

Since Devise is an engine, all its views are packaged inside the gem. These views will help you get started, but after some time you may want to change them. If this is the case, you just need to invoke the following generator, and it will copy all views to your application:

$ rails generate devise:views

If you have more than one Devise model in your application (such as User and Admin), you will notice that Devise uses the same views for all models. Fortunately, Devise offers an easy way to customize views. All you need to do is set config.scoped_views = true inside the config/initializers/devise.rb file.

After doing so, you will be able to have views based on the role like users/sessions/new and admins/sessions/new. If no view is found within the scope, Devise will use the default view at devise/sessions/new. You can also use the generator to generate scoped views:


$ rails generate devise:views users

If you would like to generate only a few sets of views, like the ones for the registerable and confirmable module, you can pass a list of modules to the generator with the -v flag.


$ rails generate devise:views -v registrations confirmations

Configuring controllers

If the customization at the views level is not enough, you can customize each controller by following these steps:

Create your custom controllers using the generator which requires a scope:

$ rails generate devise:controllers [scope]

If you specify users as the scope, controllers will be created in app/controllers/users/. And the sessions controller will look like this:


class Users::SessionsController < Devise::SessionsController
  # GET /resource/sign_in
  # def new
  #   super
  # end
  ...
end

(Use the -c flag to specify a controller, for example: rails generate devise:controllers users -c=sessions)

Tell the router to use this controller:


devise_for :users, controllers: { sessions: 'users/sessions' }

Copy the views from devise/sessions to users/sessions. Since the controller was changed, it won't use the default views located in devise/sessions.

Finally, change or extend the desired controller actions.

You can completely override a controller action:


class Users::SessionsController < Devise::SessionsController
  def create
    # custom sign-in code
  end
end

Or you can simply add new behavior to it:


class Users::SessionsController < Devise::SessionsController
  def create
    super do |resource|
      BackgroundWorker.trigger(resource)
    end
  end
end

This is useful for triggering background jobs or logging events during certain actions.

Remember that Devise uses flash messages to let users know if sign in was successful or unsuccessful. Devise expects your application to call flash[:notice] and flash[:alert] as appropriate. Do not print the entire flash hash, print only specific keys. In some circumstances, Devise adds a :timedout key to the flash hash, which is not meant for display. Remove this key from the hash if you intend to print the entire hash.

Configuring routes

Devise also ships with default routes. If you need to customize them, you should probably be able to do it through the devise_for method. It accepts several options like :class_name, :path_prefix and so on, including the possibility to change path names for I18n:


devise_for :users, path: 'auth', path_names: { sign_in: 'login', sign_out: 'logout', password: 'secret', confirmation: 'verification', unlock: 'unblock', registration: 'register', sign_up: 'cmon_let_me_in' }

Be sure to check devise_for documentation for details.

If you have the need for more deep customization, for instance to also allow "/sign_in" besides "/users/sign_in", all you need to do is create your routes normally and wrap them in a devise_scope block in the router:


devise_scope :user do
  get 'sign_in', to: 'devise/sessions#new'
end

This way, you tell Devise to use the scope :user when "/sign_in" is accessed. Notice devise_scope is also aliased as as in your router.

Please note: You will still need to add devise_for in your routes in order to use helper methods such as current_user.


devise_for :users, skip: :all