A quick question I asked ChatGPT-4:
Can you show me an example of user authentication for a Ruby on Rails 7 application?
Here was the response I got:
Sure, in this example I’ll show how to implement a basic user authentication in a Ruby on Rails 7 application using a simplified version of the “has_secure_password” mechanism, provided by Rails through the BCrypt gem.
The below steps assume you already have a Rails 7 application created. If you don’t, create a new one with the following command:
rails new my_app
Step 1: Add the bcrypt gem to your Gemfile. It is usually already there, uncommented.
Step 2: Run the bundle command.
Step 3: Generate the User model.
rails generate model User username:string password_digest:string
Step 4: Migrate the database.
Step 5: Add has_secure_password to the User model. This is the line that will give our User model authentication methods via bcrypt.
# app/models/user.rb class User < ApplicationRecord has_secure_password end
This macro adds methods to set and authenticate against a BCrypt password. This mechanism requires a password_digest attribute.
Step 6: Create the Signup form.
<!-- app/views/users/new.html.erb --> <h1>Signup</h1> <%= form_for @user do |f| %> <%= f.label :username %> <%= f.text_field :username %> <%= f.label :password %> <%= f.password_field :password %> <%= f.submit "Sign up" %> <% end %>
Step 7: Add Signup method to UsersController.
# app/controllers/users_controller.rb class UsersController < ApplicationController def new @user = User.new end def create @user = User.new(user_params) if @user.save session[:user_id] = @user.id redirect_to '/welcome' else redirect_to '/signup' end end private def user_params params.require(:user).permit(:username, :password) end end
Step 8: Setup the routing for signup.
# config/routes.rb Rails.application.routes.draw do get 'signup', to: 'users#new' post 'signup', to: 'users#create' end
Step 9: Create a Welcome controller and view.
rails generate controller Welcome index
Update the welcome/index.html.erb file:
<!-- app/views/welcome/index.html.erb --> <h1>Welcome, <%= @current_user.username %></h1>
# app/controllers/welcome_controller.rb class WelcomeController < ApplicationController before_action :set_current_user def index end private def set_current_user @current_user = User.find(session[:user_id]) end end
And add the corresponding route:
# config/routes.rb Rails.application.routes.draw do get 'signup', to: 'users#new' post 'signup', to: 'users#create' get 'welcome', to: 'welcome#index' end
This is a very simple setup without much error handling or feedback for the user, but it illustrates the core of how a basic authentication system could be implemented in Rails. In a production application, additional measures such as validations, encryption, token generation, expiration, etc. should be considered.