1. What’s new in
4.1(Chennai.rb March meetup)

2. (@vysakh0)
Vysakh Sreenivasan
Just want to build cool apps for me and
others

3. - Rails app probably take around ~5
seconds to boot.
- 50 times a day (test, rails s, rails g...)
i.e You waste 5days in a YEAR

4. #1 Spring preloader
built in integration in Rails 4.1

5. keeps app running in the background
No booting every time you run a test,
rake task or migration

6. PARTY IN THOSE 5 DAYS

7. How do you load api keys in Rails?
- create .yml, .rb file and load or
- figaro gem or
- dotenv gem.

8. #2 config/secrets.yml
generated by Rails 4.1

9. Just put your api keys in secrets.yml
# config/secrets.yml
development:
facebook_consumer_key: “random skdfjks”
facebook_consumer_secret: “its a secret”
# config/secrets.yml
development:
facebook_consumer_key: “random key”
facebook_consumer_secret: “its a secret”
# config/initializers/devise.rb
…..
config.omniauth :facebook, Rails.application.secrets.facebook_consumer_key , Rails.
application.secrets.facebook_consumer_secret
…..
Just use it like this

10. Config

11. How do you change the state of Order
- to pending.
- to completed.
- to refunded

12. Create separate columns?
- completed(:boolean) , refunded(:boolean)
Create an integer column?
- 0 -> pending
- 1 -> completed
- 2-> refunded

13. #3 Active Record enums
in Rails 4.1

14. # app/modes/order.rb
class Order < ActiveRecord::Base
# status is an integer column in orders table
enum status: {
pending: 0,
completed: 1,
refunded: 2
}
end

15. Now enum gives us
handy helper methods

16. @order.pending?
@order.completed!
@order.completed?
@order.refunded!
@order.refunded?

18. #4 Application Message Verifier
built in helper in Rails 4.1

19. irb> @user.id
# => 1
irb> user_token = Rails.application.message_verifier
(“remember_me”). generate(@user.id)
=> "BAhpBg==--859750a419640d18d7c24e3166541a9405a42786"
irb> get_back_user_id = Rails.application.
message_verifier(“remember_me”). verify(user_token)
=> 1

20. USE CASES
- Password reset
- Invite links
- Oauth tokens
- and more

21. Show different templates to
phone/browsers/tablets ?

23. #5 Application Pack Variants
(Code example taken from
http://coherence.io/blog/2013/12/17/whats-new-in-rails-4-1.html )

24. class ApplicationController < ActionController ::Base
before_action :detect_device_variant
private
def detect_device_variant
case request.user_agent
when /iPad/i
request.variant = :tablet
when /iPhone/i
request.variant = :phone
end
end
end

25. class PostController < ApplicationController
def show
@post = Post.find(params[:id])
respond_to do |format|
format.json
format.html # /app/views/posts/show.html.erb
format.html.phone # /app/views/posts/show.html+phone.erb
format.html.tablet do
@show_edit_link = false
end
end
end
end

26. #6 Application Mailer Previews

27. class NotifierPreview < ActionMailer::Preview
def welcome
Notifier.welcome(User.first)
end
end
# test/mailers/notifier_preview.rb

28. List of all mailer previews
http://localhost:3000/rails/mailers