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Demo Devise authentication

Rails demonstration application that shows how to set up the Devise gem for user authentication.

Start

Create a new Rails application:

rails new demo_devise --database=postgresql --skip-bundle
cd demo_devise

Bundle:

bundle install --path vendor/bundle --binstubs vendor/bundle/binstubs
echo /vendor >> .gitignore

Initialize the database:

bin/rake db:create db:migrate

Test:

bin/rake test

Launch

Start the Rails server:

bin/rails server

Browse http://localhost:3000 and you see the application running.

Home Page

Edit config/routes.rb and change the root path to this:

root 'home#index'

Generate:

bin/rails generate controller home index

Browse http://localhost:3000 to see the new home page.

Messages

Edit app/views/layouts/application.html.erb and insert these lines after the body tag:

<body>
  <p class="notice"><%= notice %></p>
  <p class="alert"><%= alert %></p>

Mailers

Edit config/environments/development.rb and add this:

# Set a default host that will be used in all mailers.
config.action_mailer.default_url_options = { host: 'localhost', port: 3000 }

Do the same for test.rb and production.rb for now; you will need to change these later.

Generate User

Generate a user:

rails generate resource user name:string
bin/rake db:migrate

Devise

Edit Gemfile:

# Use Devise for user authentication
gem 'devise'

Bundle:

bundle

Verify config/environments/development.rb sets the mailer default, such as:

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

Verify app/views/layouts/application.html.erb shows messges, such as:

<p class="notice"><%= notice %></p>
<p class="alert"><%= alert %></p>

Verify config/routes.rb has a root line, such as:

root 'home#index'

Generate:

rails generate devise:install
rails generate devise user
bin/rake db:migrate

Edit test/fixtures/users.yml and add a unique email address to each user:

one:
  name: MyString
  email: user1@example.com
two:
  name: MyString
  email: user2@example.com

Devise upgrades

Devise upgrades the application and user model with these capabilities:

email
encrypted password
sign in tracking
confirmable accounts
lockable accounts

The db/schema.rb users section looks like this:

create_table "users", force: :cascade do |t|
  t.string   "name"
  t.datetime "created_at",                          null: false
  t.datetime "updated_at",                          null: false
  t.string   "email",                  default: "", null: false
  t.string   "encrypted_password",     default: "", null: false
  t.string   "reset_password_token"
  t.datetime "reset_password_sent_at"
  t.datetime "remember_created_at"
  t.integer  "sign_in_count",          default: 0,  null: false
  t.datetime "current_sign_in_at"
  t.datetime "last_sign_in_at"
  t.inet     "current_sign_in_ip"
  t.inet     "last_sign_in_ip"
end
add_index "users", ["email"], name: "index_users_on_email", unique: true, using: :btree
add_index "users", ["reset_password_token"], name: "index_users_on_reset_password_token", unique: true, using: :btree

Devise authentication

Edit app/controllers/home_controller.rb and add authentication:

class HomeController < ApplicationController
  before_action :authenticate_user!

Browse http://localhost:3000 and you now see the Devise sign in page.

The page says “You need to sign in or sign up before continuing.”

Email: alice@example.com
Password: secretive

You should see: “Welcome! You have signed up successfully.”

To see the new user record in Rails:

bin/rails console

> User.first.email
  User Load (0.7ms)  SELECT  "users".* FROM "users"  ORDER BY "users"."id" ASC LIMIT 1
=> "alice@example.com"

SixArm » Rails » Demo Devise authentication