Slides from my OSCON 2010 talk "Upgrading to Rails 3". For more information including a livecoding session of upgrading a simple Rails app from 2.3 to 3, visit http://bit.ly/rails-upgrade-talk

1. Upgrading to
Rails 3
OSCON 2010
Thursday, July 22, 2010

2. Michael Bleigh
@mbleigh
OSCON 2010
Thursday, July 22, 2010

3. Thursday, July 22, 2010

4. Jeremy McAnally’s
Rails Upgrade Handbook
bit.ly/railsupgrade
OSCON 2010
Thursday, July 22, 2010

5. Rails 3 is
Different
OSCON 2010
Thursday, July 22, 2010

6. Rails 3 is a
Bi ange
OSCON 2010
Thursday, July 22, 2010

7. Why the hell
should I bother?
OSCON 2010
Thursday, July 22, 2010

8. Modularity
OSCON 2010
Thursday, July 22, 2010

9. Rails 2.3 Stack
ActiveRecord
ActiveSupport
ActiveResource
ActionPack
Test::Unit
OSCON 2010
Thursday, July 22, 2010

10. Rails 3 Ecosystem
DataMapper
ActiveRecord MongoMapper
ActiveSupport
ActiveResource ActiveModel
ActionPack
RSpec Bacon
Test::Unit
OSCON 2010
Thursday, July 22, 2010

11. Rails 2.3 Controller
ActionController::Base
ApplicationController
YourController
OSCON 2010
Thursday, July 22, 2010

12. Rails 3 Controller
AbstractController::Base
ActionController::Metal
ActionController::Base
ApplicationController
YourController
OSCON 2010
Thursday, July 22, 2010

13. Less Monkeypatching
OSCON 2010
Thursday, July 22, 2010

14. Security
darwinbell via Flickr
OSCON 2010
Thursday, July 22, 2010

15. small change,
big impact
OSCON 2010
Thursday, July 22, 2010

16. HTML is escaped
by default.
OSCON 2010
Thursday, July 22, 2010

17. <!-- Rails 2.3 -->
<div class='comment'>
<%= comment.body %>
</div>
<!-- Rails 3 -->
<div class="comment">
<%= comment.body.html_safe %>
</div>
<!-- Rails 3 (alternate) -->
<div class="comment">
<%=raw comment.body %>
</div>
Thursday, July 22, 2010

18. It’s a good thing.TM
OSCON 2010
Thursday, July 22, 2010

19. New Apis
OSCON 2010
Thursday, July 22, 2010

20. e Router
OSCON 2010
Thursday, July 22, 2010

21. Rack Everywhere!
OSCON 2010
Thursday, July 22, 2010

22. Fancy New DSL
OSCON 2010
Thursday, July 22, 2010

23. More Powerful
OSCON 2010
Thursday, July 22, 2010

24. # Rails 2.3
map.connect '/help', :controller => 'pages',
:action => 'help'
# Rails 3
match '/help', :to => 'pages#help'
# Rails 2.3
map.resources :users do |users|
users.resources :comments
end
# Rails 3
resources :users do
resources :comments
end
Thursday, July 22, 2010

25. # Rails 2.3
with_options :path_prefix => 'admin',
:name_prefix => 'admin' do |admin|
admin.resources :users
admin.resources :posts
end
# Rails 3
namespace :admin
resources :users
resources :posts
end
Thursday, July 22, 2010

26. # Rails 3
constraints(:subdomain => 'api') do
resources :statuses
resources :friends
end
match '/hello', :to => lambda{ |env|
[200, {'Content-Type' => 'text/plain'}, 'Hello
World']
}
match '/other-site', :to => redirect('http://url.com')
Thursday, July 22, 2010

27. A ionMailer
OSCON 2010
Thursday, July 22, 2010

28. It’s (mostly) just
a controller.
OSCON 2010
Thursday, July 22, 2010

29. class Notifier < ActionMailer::Base
default :from => "mikel@example.org"
def welcome_email(user)
@name = user.name
attachments['terms.pdf'] = File.read(
Rails.root.join('docs/terms.pdf')
)
mail(:to => user.email, :subject => "G’day Mate!")
end
end
Thursday, July 22, 2010

30. class UsersController < ApplicationController
respond_to :html
def create
@user = User.new(params[:user])
Notifier.welcome_email(@user).deliver if @user.save
respond_with @user
end
end
Thursday, July 22, 2010

31. Bundler
OSCON 2010
Thursday, July 22, 2010

32. Caution: Entering
Controversy
OSCON 2010
Thursday, July 22, 2010

33. # Rails 2.3
# environment.rb
config.gem 'acts-as-taggable-on'
config.gem 'ruby-openid', :lib => false
# test.rb
config.gem 'rspec'
config.gem 'cucumber'
# Rails 3
# Gemfile
gem 'acts-as-taggable-on'
gem 'ruby-openid', :require => false
group :test do
gem 'rspec'
gem 'cucumber'
end
Thursday, July 22, 2010

34. Dependency
Resolver
OSCON 2010
Thursday, July 22, 2010

35. A iveRelation
OSCON 2010
Thursday, July 22, 2010

36. Like named scopes,
only more so.
OSCON 2010
Thursday, July 22, 2010

37. # Rails 2.3
Book.all(
:conditions => {:author => "Chuck Palahniuk"},
:order => "published_at DESC",
:limit => 10
)
# Rails 3
Book.where(:author => "Chuck Palahniuk")
.order("published_at DESC").limit(10)
Thursday, July 22, 2010

38. Inherently
Chainable
Thursday, July 22, 2010

39. # Rails 3
def index
@books = Book.where(:author => params[:author])
if params[:author]
@books = @books.order(:title) if params[:sort] ==
'title'
respond_with @books
end
Thursday, July 22, 2010

40. # Rails 2.3
class Book
named_scope :written_by {|a| {:conditions => {:author => a}}}
named_scope :after {|d| {:conditions => ["published_on > ?", d]}}
# Rails 3
class Book
class << self
def written_by(name)
where(:author => name)
end
def after(date)
where(["published_on > ?", date])
end
end
end
Thursday, July 22, 2010

41. Be er H ks
OSCON 2010
Thursday, July 22, 2010

42. Generators
OSCON 2010
Thursday, July 22, 2010

43. config.generators do |g|
g.orm :mongomapper
g.test_framework :rspec
g.integration_tool :rspec
end
rails g model my_model
Thursday, July 22, 2010

44. Engines
OSCON 2010
Thursday, July 22, 2010

45. #lib/your_plugin/engine.rb
require "your_plugin"
require "rails"
module YourPlugin
class Engine < Rails::Engine
engine_name :your_plugin
end
end
Thursday, July 22, 2010

46. Lots more...
railsdispatch.com
edgeguides.rubyonrails.org
OSCON 2010
Thursday, July 22, 2010

47. But we’re already
on Rails 2.3!
OSCON 2010
Thursday, July 22, 2010

48. How do we cope?
OSCON 2010
Thursday, July 22, 2010

49. Ignore it all
and cheat.
github.com/rails/
rails_upgrade
OSCON 2010
Thursday, July 22, 2010

50. Finds Key
Blockers:
Routes, Bundler,
application.rb
OSCON 2010
Thursday, July 22, 2010

51. 3 Step Process
OSCON 2010
Thursday, July 22, 2010

52. Analyze Your App
rake rails:upgrade:check
OSCON 2010
Thursday, July 22, 2010

53. Backup 2.3 Files
rake rails:upgrade:backup
OSCON 2010
Thursday, July 22, 2010

54. Run Upgrades
rake rails:upgrade:routes
rake rails:upgrade:gems
rake rails:upgrade:configuration
OSCON 2010
Thursday, July 22, 2010

55. Takeaways
OSCON 2010
Thursday, July 22, 2010

56. Tests help.
Unfortunately, they
may not run.
Thursday, July 22, 2010

57. Don’t be afraid to
re-generate.
Thursday, July 22, 2010

58. Just take it one
problem at a time.
Thursday, July 22, 2010

59. estions?
@mbleigh @intridea
github.com/mbleigh/upgrade-to-rails3
OSCON 2010
Thursday, July 22, 2010