To implement user authentication in Ruby on Rails, you can use the Devise gem. Devise is a flexible authentication solution that provides a set of ready-to-use controllers and views for user registration, login, and password recovery.
Here are the steps to implement user authentication using Devise:
1. Add Devise to your Gemfile:
“`ruby
gem ‘devise’
“`
2. Install the gem by running the following command in your terminal:
“`bash
bundle install
“`
3. Generate the Devise configuration files by running the following command:
“`bash
rails generate devise:install
“`
4. Generate a User model with Devise by running the following command:
“`bash
rails generate devise User
“`
5. Run the database migration to create the necessary tables:
“`bash
rails db:migrate
“`
6. Add the following line to your application layout file (`app/views/layouts/application.html.erb`) to display flash messages:
“`ruby
<%= flash[:notice] %>
<%= flash[:alert] %>
“`
7. Add the following line to your application controller (`app/controllers/application_controller.rb`) to require authentication for all actions:
“`ruby
before_action :authenticate_user!
“`
8. Customize the Devise views by running the following command:
“`bash
rails generate devise:views
“`
9. Customize the routes in `config/routes.rb` to specify the controllers and actions for user registration, login, and password recovery:
“`ruby
devise_for :users, controllers: {
registrations: ‘users/registrations’,
sessions: ‘users/sessions’,
passwords: ‘users/passwords’
}
“`
10. Customize the user registration, login, and password recovery controllers by creating the corresponding files in the `app/controllers/users` directory. For example, you can create `app/controllers/users/registrations_controller.rb` with the following content:
“`ruby
class Users::RegistrationsController < Devise::RegistrationsController
# Custom code here
end
“`
11. Customize the user views by modifying the files in the `app/views/devise` directory.
That’s it! You now have user authentication implemented in your Ruby on Rails application using Devise. You can further customize the authentication process by adding additional fields to the User model or by modifying the Devise controllers and views.