Part 5 of 6

1. Building Web Apps with Rails
V

2. Recap
● Generating Controllers
● Nesting Resources
● Nesting in Routes
● Nesting in Controllers
● Nesting in Views

3. First FM
rails generate controller streams
index new create destroy
In other words:
rails generate controller <controller name> <actions>

4. StreamsController should really...
●
Index - show all streams belonging to a station
● New - show the form to create a stream
belonging to a station
●
Create - take form data and saves a stream
belonging to a station
●
Destroy - delete a stream from the database

5. streams_controller.rb
def index
@streams = Stream.all
end
We want to select a station and get all its
streams

6. Answer: we're going to pass it in the url by
nesting resources
http://127.0.0.1:3000/stations/1/streams
We're going to tell the routes to interpret
this as :station_id

7. Session 5: Authentication
● User Model
● Installing Gems with Bundler
● Authentication with Devise

8. Session 5: Authentication
At present, anyone can CRUD
(Create Read Update Destroy)

9. Session 5: Authentication
At present, anyone can CRUD
(Create Read Update Destroy)
Signed in Users Public

10. Session 5: Authentication
At present, anyone can CRUD
(Create Read Update Destroy)
Signed in Users Public

11. Authentication: How?
● Create a user model
● Authenticate using email & password
● Create a session
● We're going to use Devise to do this

12. Authentication: How?
Devise Provides:
● MVC components for authentication
● A controller for creating / destroying sessions
● A sign in form
● Links / Routes to sign in / sign out

14. Installing Devise with
Install and manage gems
Gems are specified in the gemfile
This is found in the 'firstfm' directory

15. gem 'rails', '3.1.1'
# Bundle edge Rails instead:
# gem 'rails', :git => 'git://github.com/rails/rails.git'
gem 'sqlite3'
# Gems used only for assets and not required
# in production environments by default.
group :assets do
gem 'sass­rails', '~> 3.1.4'
gem 'coffee­rails', '~> 3.1.1' We can specify:
gem 'uglifier', '>= 1.0.3'
end Versions
Sources
gem 'jquery­rails' When to use them
group :test do
# Pretty printed test output
gem 'turn', :require => false
gem 'minitest'
end The Gemfile

16. Installing Devise
Add the line
gem 'devise'
To your gemfile, in the terminal run:
bundle install
rails generate devise:install

17. Generating the User Model
We will use Devise's optional template to
generate a user model.
rails generate devise User
This gives us:
User Model
Migration for User
Controller & Views for Users
User Routes

18. Generated User Model & Stuff
Check out routes with rake routes
In models/user.rb:
devise :database_authenticatable,
:registerable, :recoverable,
:rememberable, :trackable,
:validatable
(A variety of modules provided by devise)

19. Adding the User Model
Once you're happy, run the migration script:
rake db:migrate
… fire up the server and go to
127.0.0.1:3000/users/sign_up

20. More Devise Goodies
Returns the user object for the signed in user.
current_user
Returns true or false whether the user is signed in.
user_signed_in?

21. Am I logged in?
In views/layouts/Application.html.erb:
<% if user_signed_in? %>
<p>hello <%= current_user.email %></p>
<% end %>

22. So where are these views?
rails generate devise:views

23. Task! Add Login Links
Provide links for our user to sign up, sign in / sign
out.
(Hint! Check out the Devise wiki on Github)
https://github.com/plataformatec/devise/wiki/

24. Authenticate!
Is the user authenticated?
authenticate_user!

25. But be dry!
Use a before filter
before_filter :authenticate_user!

26. But be dry!
Use a before filter
before_filter :authenticate_user!
e.g.
class StationsController
before_filter
:authenticate_user!, :except =>
[:index, :show]
…