Another new version of Rails. Delightful. And terrifying. What's changed this time? Fear Not! We'll be reviewing the changes and additions to Rails 3.1, giving you a walk-through of what it all means (asset pipeline, what?), in the context of a brand new app, and an older app that will need to be upgraded.

1. Rails 3.1
Lori Olson
Confoo 2012
Montreal, QC

2. Another new version of Rails.
Delightful. And terrifying.
What's changed this time?

3. Summary
• jQuery
• CoffeeScript
• SASS
• Asset Pipeline
• Miscellaneous cool stuff

4. But...
• What about Rails 3.2?
• only released a few weeks ago
• not nearly as many scary changes

5. jQuery

6. What you HAVE to know
• How to go back to Prototype (not
recommended
• rails new my_app -j prototype

7. Differences
• Gemfile
gem ‘jquery-rails’
• application.js
//= require jquery
//= require jquery_ujs

8. But... Why jQuery?

10. CoffeeScript

11. What you HAVE to know
• Nothing
• Absolutely not required
• Just remove one line from Gemfile
• gem 'coffee-rails'
• And you don’t even have to do this

12. Thomas Fuchs on
CoffeeScript
• May 2011 - "I just like javascript too
much to have a use for that, but I
understand why other people might
like it"
• Aug 2011 - There, it happened.
Mistakenly typed CoffeeScript in a .js
file. So easy to pick up, and so natural.

13. CoffeeScript Resources
• Railscasts
• CoffeeScript Basics
• http://railscasts.com/episodes/267-coffeescript-basics
• Peepcode
• Meet CoffeeScript
• http://peepcode.com/products/coffeescript
• Books
• Pragmatic Programmers - CoffeeScript
• O’Reilly - The Little Book on CoffeeScript

14. SASS

15. What you HAVE to know
• Nothing
• Absolutely not required
• Just remove one line from your Gemfile
• gem 'sass-rails'
• And you don’t even have to do that

16. Is it SASS or SCSS?
• Sass is the older style HAML-like
indented syntax
• SCSS is the new main syntax, which is a
superset of CSS3

17. Why SASS?
• Variables
• Nesting
• DRY up your styles
• Mixins
• reusable chunks
• with arguments!
• Selector Inheritance

18. Alternatives to SASS
• Less
• HSS
• Other, technology specific
• XCSS (PHP)
• CleverCss (Python)
• CSS Crush (PHP)

19. Asset Pipeline

20. assets dir

21. assets dir

22. assets dir

23. assets dir

24. js manifest
• Powered by - Sprockets
• application.js
// FIXME: Tell people that this is a manifest
file, real code should go into discrete files
//
//= require jquery
//= require jquery_ujs
//= require_tree .

25. SASS - no sprockets
• probably don’t want to use manifests
• use @import, or your variables and
scopes will not work

26. Dev vs Production
• To precompile, or not to precompile
• Heroku
• Cedar stack
• counter-intuitive settings

27. Compression
• Uglifier (for javascript)
• SCSS (for css)

28. But, Why?

29. Identity Map

30. enabling
• application.rb
# Enable IdentityMap for Active Record,
to disable set to false or remove the line
below.
config.active_record.identity_map = true

31. problems
• associations
• STI
• tests

32. nested
has_many :through

33. class Project < ActiveRecord::Base
has_many :tasks
has_many :assignments, :through => :tasks
has_many :users, :through => :assignments
end

34. Migrations

35. class CreateProjects < ActiveRecord::Migration
def change
create_table :projects do |t|
t.string :name
t.timestamps
end
end
end

36. HTTP Streaming

37. requirements
• Ruby 1.9.2 (min)
• Web server support
• nginx
• unicorn

38. Examples

39. New App

40. Upgrade

41. Bundler
• Did you know... you can use bundler all
the way down to Rails 2.1 apps?

42. Add Bundler
• http://youtu.be/7UzGdqaDnp8

43. • Upgrade the Gemfile
• Config file changes
• Move the assets

44. Configs
• boot.rb
• config.rb
• development.rb
• production.rb

45. Assets
• Move asset folders
• Fix image references
• Manifests
• stylesheet and javascript tag references

46. Upgrade Demo
• Upgrading a Rails 2.1 app to Rails 3.1 in
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