An overview of some of the new features in Rails 4. All features are discussed in depth in the e-book Upgrade to Rails 4 (http://www.leanpub.com/upgradetorails4) as well.

1. RIDING
RAILS 4

2. #BCNONRAILS4

3. PHILIP DE SMEDT
@PHILIPDESMEDT
PHILIPDESMEDT.COM

4. FREELANCE
FULL-STACK
DEVELOPER
(HIRE ME)

5. I WROTE A BOOK
UPGRADE TO RAILS 4

6. WHO HAS
TRIED RAILS 4?
gem install rails --version
4.0.0.beta1 --no-ri --no-rdoc

7. TURBOLINKS

8. CLICK
LISTENS TO
EVENTS

9. LISTENS TO CLICK EVENTS
LOADS CONTENT
WITHOUT
RELOADING
THE PAGE

10. LISTENS TO CLICK EVENTS
LOADS CONTENT WITHOUT
RELOADING THE PAGE
REPLACES BODY+TITLE
HTML5
USING
pushState

11. DEMO

12. RUSSIAN DOLL CACHING

13. LET’S CACHE
class Post < ActiveRecord::Base
has_many :categories
end
class Category < ActiveRecord::Base
belongs_to :post, touch: true
end

14. RAILS 3
<!-- app/views/posts/show.html.erb -->
<% cache [„v1‟, @post] do %>
<h1><%= @post.title %> categories:</h1>
<ul><%= render @post.categories %></ul>
<% end %>

15. RAILS 3
<!-- app/views/categories/_category.html.erb -->
<% cache [„v1‟, category] do %>
<li>
<%= category.title %>
<%= link_to “edit”, category %>
</li>
<% end %>

16. RAILS 3 CACHE KEYS
views/v1/posts/1-
20130228151844

17. RAILS 3
<!-- app/views/categories/_category.html.erb -->
<% cache [„v2 ‟, category] do %>
<li>
<%= category.title %>
<%= link_to “RENAME”, category %>
</li>
<% end %>

18. RAILS 3
<!-- app/views/posts/show.html.erb -->
<% cache [„v2‟, @post] do %>
<h1><%= @post.title %> categories:</h1>
<ul><%= render @post.categories %></ul>
<% end %>

20. <!-- app/views/posts/show.html.erb -->
<% cache @post do %>
<h1><%= @post.title %> categories:</h1>
<ul><%= render @post.categories %></ul>
<% end %>
<!-- app/views/categories/_category.html.erb -->
<% cache category do %>
<li>
<%= category.title %>
<%= link_to “edit”, category %>
</li>
<% end %>

21. RAILS 4 CACHE DIGEST
views/posts/1-
20130228151844/fbda9857
614e68ed1df453559a761d4
7

22. STRONG PARAMETERS

23. RAILS 3
class User < ActiveRecord::Base
attr_accessible :name, :email
end
def create
@user = User.new(params[:user])
@user.save
end

24. EXAMPLE

25. RAILS 4
class CarsController < ApplicationController
def create
@car = Car.new(car_params)
if @car.save
redirect_to @car
else
render „new‟
end
end
end

26. private
def car_params
params.require(:car).permit(:name, :year, :brand)
end
require(key) - Ensures that a parameter is present. If it‟s present,
returns the parameter at the given key, otherwise raises an
ActionController:: ParameterMissing error.
permit(filters) - Returns a new ActionController::Parameters
instance that includes only the given filters
and sets the permitted attribute for the object to true. This is useful
for limiting which attributes should be allowed for mass updating.

27. LIVE STREAMING

28. ACTIONCONTROLLER::LIVE
MIXIN I/O OBJECT
STREAM DATA TO CLIENT

29. DON’T USE
WEBrick
USE PUMA OR RAINBOWS!

30. RUNS IN
SEPARATE
THREAD

31. CLOSE YOUR
STREAM WHEN
DONE

32. PUMA vs.
RAINBOWS! vs.
NODE.JS
RUBYSNIPPETS.COM

34. DEMO

35. ACTIVEMODEL::MODEL

36. FORM WITHOUT
ACTIVE RECORD.
WTF?

37. FORM_TAG
HELPER
CREATE MODEL

38. EXAMPLE

39. class Contact
include ActiveModel::Model
attr_accessor :name, :email, :message
validates :name, presence: true
validates :email, presence: true
validates :message, presence: true, length:
{ maximum: 300 }
end
contact = Contact.new(name: 'John Doe', email:
'john@doe.com', message: 'a test')

40. <h1>Contact Us</h1>
<%= form_for @contact do |f| %>
<%= f.label :name %>
<%= f.text_field :name %>
<%= f.label :email %>
<%= f.email_field :email %>
<%= f.label :message %>
<%= f.text_area :message %>
<%= f.submit 'Submit' %>
<% end %>

41. class ContactsController < ApplicationController
def new
@contact = Contact.new
end
def create
@contact = Contact.new(params[:contact])
if @contact.valid?
UserMailer.new_contact(@contact).deliver
redirect_to root_path, notice: "Message sent! Thanks.”
else
render :new
end
end
end

42. LOTS OF OTHER STUFF
ROUTING CONCERNS THREAD SAFETY
CONTROLLER-WIDE E-TAGS ENCRYPTED COOKIES
HTTP PATCH VERB
CUSTOM FLASH TYPES
HTML5 FORM HELPERS
SCHEMA CACHE DUMP
PAGE/ACTION CACHING
NO MORE OBSERVERS/SWEEPERS
ACTIVE RESOURCE INDEX PAGE CONTROLLER

43. EDUCATION IS BROKEN.
I’LL BE TEACHING RAILS…
IN BARCELONA.
I <3 DEVBOOTCAMP/STARTER LEAGUE/…

44. COME SAY HI
PHILIP DE SMEDT
@PHILIPDESMEDT
PHILIPDESMEDT.COM
LEANPUB.COM/UPGRADETORAILS4