Subscription-app

• create a new rails application named subscription-app

rails new subscription-app -d mysql

• Enter your application

cd subscription-app

If you setup MySQL or Postgres with a username/password, modify the config/database.yml file to contain the username/password that you specified

• Make sure that MySQL server is running. Just type mysql. If you get an error like this:

ERROR 2002 (HY000): Can't connect to local MySQL server through socket '/var/run/mysqld/mysqld.sock' (2)

It's most likely that MySQL server is not running. You can start it with:

sudo service mysql start

• Generate the database

rake db:create

• Open your project in Visual Studio Code. You can type explorer.exe . to open the project on windows (for BashOnUbuntuOnWindows).

Introducing Devise

• Devise provides a number of user routes automatically.
• Session routes for Authenticatable (default):

User/scope	Method	Route	Controller Action
new_user_session	GET	/users/sign_in	devise/sessions#new
destroy_user_session	DELETE	/users/sign_out	devise/sessions#destroy
new_user_registration	GET	/users/sign_up	devise/registrations#new

For other available routes, look at SessionsController and RegistrationsController

• URL helpers are provided to be used with resource/scope. They act like proxies to the generated routes created by devise. Example:

User/scope	URL helper
new_user_session	new_user_session_path
destroy_user_session	destroy_user_session_path
new_user_registration	new_user_registration_path

• Devise provides a number of user helpers automatically.

Roles: User Admin

Generated methods: authenticate_user! # Signs user in or redirect authenticate_admin! # Signs admin in or redirect user_signed_in? # Checks whether there is a user signed in or not admin_signed_in? # Checks whether there is an admin signed in or not current_user # Current signed in user current_admin # Current signed in admin user_session # Session data available only to the user scope admin_session # Session data available only to the admin scope

Use: before_action :authenticate_user! # Tell devise to use :user map before_action :authenticate_admin! # Tell devise to use :admin map

• Users have an email and password
• Use Devise for drop-in authentication
• Devise includes modules for additional functionality: Encrypt password, OmniAuth, Email confirmation, Recover password, Lock account, Expire session.
• Devise configures the user table with same default columns.

Name	Type
id	integer
email	character varying
encrypted_password	character varying
sign_in_count	integer
current_sign_in_at	timestamp without time zone
created_at	timestamp without time zone
updated_at	timestamp without time zone

Add Devise

• For instructions on installing Devise go to getting started

Small recap:

1. gem 'devise' in Gemfile
2. $ bundle install
3. $ rails generate devise:install
4. config.action_mailer.default_url_options = { host: 'localhost', port: 3000 } in config/environments/development.rb
5. root to: "home#index" in config/routes.rb
6. Create and update home_controller.rb
7. Create and update views/home/index.html.erb
8. rails server (ensure that MySQL server is running)
9. Update views/layouts/application.html.erb to include <p class="notice"><%= notice %></p> and <p class="alert"><%= alert %></p>
10. $ rails generate devise User
11. $ rake db:migrate
12. rails server if your application is nor running yet

• http://localhost:3000/users/sign_in and http://localhost:3000/users/sign_up should be available and functional.

Add navigation

• Add Bootstrap CDN and <%= render 'nav' %> in views/layouts/application.html.erb
• Create and update views/application/_nav.html.erb

Add publications

• The Publication Model:
  • The digital file subscribers will have access to
  • "Lightweight" model as it is not very relevant to implementing payments
  • Should be customized based on your needs
• Publication scheme:

Name	Type
id	integer
title	character varying
file_url	character varying
description	character varying
created_at	timestamp without time zone
updated_at	timestamp without time zone

• Administrators:

  • Administrators are users with is_admin set to true
  • A initial administrator will be created, with the option to add more via the console
  • Many Ruby gems exist for handling administrators : cancan, pundit, rolify

• Administrator and Subscriber views:

  • Administrators can create, edit, and update publications
  • Subscribers can only view publications
  • Non-subscribers can see publications but not access their details

Publication Routes (Admin):

Method	Route	Controller Action
GET	/admin/publications	admin/publications#index
GET	/admin/publications/:id	admin/publications#show
GET	/admin/publications/new	admin/publications#new
POST	/admin/publications	admin/publications#create
GET	/admin/publications/:id/edit	admin/publications#edit
PUT	/admin/publications/:id	admin/publications#update
DELETE	/admin/publications/:id	admin/publications#destroy

Publication Routes (Subscriber):

Method	Route	Controller Action
GET	/publications	publications#index
GET	/publications/:id	publications#show

Publication Routes (Non-subscriber):

Method	Route	Controller Action
GET	/publications/:id	publications#show

Create the Publication model

• Create the publication model

rails g model publication title:string description:text file_url:string

• Migrate the database to generate the publication model:

rake db:migrate

• Add routes in config/routes.rb:

resources :publications, only: [:index, :show]

• Create the publications_controller.rb and the index and show views.
• To add a publication for test you can type:

rails c
p = Publication.new(title: 'My first publication', description: 'This is my first publication', file_url: 'http://myfilelocation.com')
p.save
exit

Add administrators

• Create a migration file to add the is_admin column to the users table to allow users to become admin:

rails g migration add_is_admin_to_users is_admin:boolean

• Modify the generated migration file for add_is_admin_to_users to set null to false and default to false.

add_column :users, :is_admin, :boolean, null: false, default: false

• Run the migration:

rake db:migrate

• You can test everything with the rails console:

rails c
User.last
User.last.is_admin
User.last.update(is_admin: true)

• If you wish, you can set an admin in the seeds.rb (so you have one by default):

User.create(
  email: '[email protected]',
  password: 'password',
  is_admin: true
)

Build an administrator view for publications

• Update the routes.rb to add the admin routes.
• Create the admin_controller.rb under controllers.
• Add the admin folder under controllers, and add the publications_controller.rb.
• Add the admin folder under views and, under admin folder, the publications folder and add the index.html.erb, edit.html.erb, show.html.erb, new.html.erb.
• Run rails s and navigate to localhost:3000/admin/publications to test the admin routes.

Build a subscriber view for publications

• We already did at localhost:3000/publications. You can check that everything works fine.

Stripe API

Discuss the payment processor Stripe

• Payment processors: PayPal, Authorize.Net, Stripe.
• Why Stripe?
  • PCI compliance is hard
  • Powerful API
  • Low cost
  • Great support

Understand Stripe's subscription API

• Stripe's Subscription API
  • Allows recurring charges on a schedule
  • Handles storing credit card information
  • Additional features like coupons and trial periods are also available

Integrate the Stripe library in our application

• Adding Stripe to Our application

  • Add the Stripe API gem
  • Find our Stripe API keys
  • Use dotenv to securely store API keys
  • Test the API in the console

• Go to Stripe and open an account.

• Create a new product in the Products section. Example:

Subscription App Bronze Plan 9.00 $ / month

1. Install Stripe libraries and tools

# If you use bundler, you can add this line to your Gemfile
gem 'stripe'

• Run bundle install
• Create config/initializers/stripe.rb and paste the Stripe.api_key

Stripe.api_key = 'sk_test_XXXXXXXXXXXXXXXXXXXXXX'

• To retrieve the subscription, you need to retrieve the plan using the prices API ID.
• You can test that everything works fine using the rails console:

rails c
Stripe::Plan.retrieve('price_XXXXXXXXXXXXXXXXXX')
exit

Notice: be sure to use your API key and the price_id of your product (if you are logged in, the provided examples should already have your keys and price_id).

Learn how to securely store configuration keys

• Add dotenv. A .env file can keep the API keys out of the code.
• Add the API key in a dotenv file.
• Add gem 'dotenv-rails', groups: [:development, :test] to Gemfile and run bundle install.
• Create .env file and add STRIPE_API_KEY="XXXXXXXXXXX". Make sure that .env is in .gitignore.
• Update stripe.rb: Stripe.api_key = ENV["STRIPE_API_KEY"].
• Test again in your console that everything is still working:

rails c
Stripe.api_key
exit

Add subscriptions

Build the Subscription model

• Tied to a user

• active boolean

• Stores Stripe user_id for retrieval

• Create the subscription model:

rails generate model subscription stripe_user_id:string active:boolean user:references

• Update create_subscriptions.rb migration file to ensure active can't be null and is false by default:

t.boolean :active, null: false, default: false

• Add the subscription relation to user.rb model:

has_one :subscription

• Make sure that the user relation is set in subscription.rb model:

belongs_to :user

• Run rake db:migrate

• Add an active record callback in the user.rb model to generate a default subscription to every new user:

after_create :create_subscription
def create_subscription
  Subscription.create(user_id: id) if subscription.nil?
end

• Add a new migration to ensure previous users also have a subscription:

rails g migration AddSubscriptionToPreviousUsers

• Update the add_subscription_to_previous_users.rb migration file with the up function. More details at active record migrations:

def up
  User.all.each do |user|
    user.create_subscription
  end
end

• Run rake db:migrate

We should see that a subscription is created for every existing user.

• You can also verify with rails console:

rails c
User.last.subscription
exit

Create a view to show a user's subscription status

• Generate a users controller as well as the info route where users can manage their account information:

rails generate controller users info

• Update routes.rb to indicate the controller's action users#info:

get '/users/info', to: 'users#info'

• Update users_controller.rb to add the devise helper authenticate_user and the @subscription parameter to use it in the view:

before_action :authenticate_user!
def info
  @subscription = current_user.subscription
end

• Update _nav.html.erb to add a link to users_info_path:

<% if user_signed_in? %>
<li class="nav-item">
  <%= link_to current_user.email, users_info_path %>
</li>

• Update app/views/users/info.html.erb to show if the user is subscribed or unsubscribed:

<%= current_user.email %>
<% if @subscription.active %>
subscribed
<% else %>
unsubscribed
<% end %>

• Navigate to localhost:3000/users/info to see the new changes.

Accept credit cards using Stripe.js

• Client-side JavaScript library
• Credit card information never touches our servers
• A Stripe token is used to communicate back and forth
• Gather credit card information in a form
• Send it directly to Stripe from the browser
• Recommended by Stripe
• Local Subscription model becomes super light-weight

Tie a subscription to a user with Stripe API

• Using the Stripe token, we create a subscription with the Stripe Ruby library
• The corresponding user_id from Stripe is stored locally for easy retrieval

Have a look at Create fixed-price subscriptions for subscriptions implementation.