Rails4: a Christmas tale

Presentation given during the genevarb meetup, in Geneva (Switzerland)

Transcript

1. View Slide

2. View Slide

3. Mass extraction
   • Hash-based & Dynamic finder methods
   rails / activerecord-deprecated_finders
   • Mass assignment protection in Active Record models
   rails/protected_attributes
   • ActiveRecord::SessionStore
   rails/activerecord-session_store
   • Active Record Observers
   rails/rails-observers
   • Active Resource
   rails/activeresource
   • Action Caching
   rails/actionpack-action_caching
   • Page Caching
   rails/actionpack-page_caching
   • Sprockets
   rails/sprockets-rails
   3
   

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4. View Slide

5. Ruby 1.9.3
   5
   

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6. Deprecation policy
   • Rails 3.2.x
   • new deprecation warnings
   • Rails 4.0.0
   • new features
   • new deprecation warnings
   • nothing is removed
   • easy upgrade
   • Rails 4.0.x
   • no new features
   • no new deprecation warnings
   • Rails 4.1:
   • new features
   • removes deprecated stuff
   6
   

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7. strong parameters queue API russian dolls caching
   7
   

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8. strong parameters
   queue API russian dolls caching
   7
   

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9. # app/models/kid.rb
   class Kid < ActiveRecord::Base
   attr_accessible :name, :age, :address, :girl #, :good
   end
   # app/controllers/kids_controller.rb
   class KidsController < ApplicationController
   def create
   @kid = Kid.new(params[:kid])
   if @kid.save
   redirect_to root_url
   else
   render action: "new"
   end
   end
   end
   3
   Mass-asignment protection
   8
   

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10. ActionController::StrongParameters
    4
    9
    

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11. ActionController::StrongParameters
    # app/models/kid.rb
    class Kid < ActiveRecord::Base
    end
    # app/controllers/kids_controller.rb
    class KidsController < ActionController::Base
    def create
    Kid.create(params.require(:kid).permit(:name, :age))
    end
    # Kid.create(params[:kid]) =>
    # ActiveModel::ForbiddenAttributes
    end
    4
    10
    

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12. # app/controllers/kidss_controller.rb
    class KidsController < ActionController::Base
    def create
    Kid.create(kid_params)
    end
    def update
    redirect_to kids.find(params[:id]).tap { |kid|
    kid.update_attributes!(kid_params)
    }
    end
    private
    def kid_params
    params.require(:kid).permit(:name, :age)
    end
    # params.require(:kid).permit(:name, :age, pets_attributes:
    # [ :name, :category ])
    end
    4
    ActionController::StrongParameters
    11
    

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13. 3
    Try it now!
    #gemfile
    gem 'strong_parameters', github: 'rails/strong_parameters'
    # application.rb
    config.active_record.whitelist_attributes = false
    12
    

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14. #gemfile
    gem 'protected_attributes', github: 'rails/protected_attributes'
    # application.rb
    config.active_record.whitelist_attributes = true
    Easy transition…
    4
    13
    

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15. Rails.queue
    14
    

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16. Many choices…
    • gem 'delayed_job_active_record'
    • gem 'resque'
    • gem 'sidekiq'
    • …
    3
    15
    

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17. Rails.queue (ActiveSupport::Queue)
    4
    16
    

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18. class ToySender
    attr_reader :kid_id, :toy_id
    def initialize(attr)
    @kid_id = attr[:kid_id]
    @toy_id = attr[:toy_id]
    end
    def run
    kid = Kid.find(@kid_id)
    toy = Toy.find(@toy_id)
    # toy.send_to(kid)
    end
    end
    # Then, add an instance of WishSender to Rails.queue.
    # A likely place for this code is in a controller:
    class KidsController < ApplicationController
    def send_toy
    Rails.queue << ToySender.new(params)
    flash[:notice] = "Toy queued to be sent!"
    redirect_to kids_url
    end
    end
    4
    4
    17
    

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19. # config/application.rb
    # Default Synchronous
    config.queue = ActiveSupport::SynchronousQueue.new
    # Default Threaded
    config.queue = ActiveSupport::Queue.new
    # Resque Queue
    config.queue = Resque::Rails::Queue.new
    # Sidekiq Queue
    config.queue = Sidekiq::Client::Queue.new
    # Test Queue
    config.queue = ActiveSupport::TestQueue.new
    4
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20. asynchronous ActionMailer
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21. # application.rb
    config.action_mailer.async = true
    # welcome_mailer.rb
    class WelcomeMailer < ActionMailer::Base
    self.async = true
    end
    4
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22. # application.rb
    config.action_mailer.queue = :sidekiq
    # welcome_mailer.rb
    class WelcomeMailer < ActionMailer::Base
    def queue
    MyQueue.new
    # Sidekiq::Client::Queue.new
    end
    end
    4
    21
    

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23. # kids_controller.rb
    # don’t do this! can't be marshalled (serialized) in the
    # queue system
    WelcomeMailer.welcome(@kid).deliver
    # You should do
    WelcomeMailer.welcome(@kid.id).deliver
    # welcome_mailer.rb
    class WelcomeMailer < ActionMailer::Base
    def welcome(id)
    @kid = User.find(id)
    # prepare your mail
    end
    end
    4
    22
    

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24. russian dolls caching
    23
    

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25. 3
    - cache [ "v1", kid ] do
    %h1 All toys
    = render kid.toys
    ! - cache [ "v1", toy ] do
    %h2= toy.name
    ! = render toy.elves
    ! ! - cache [ "v1", elf ] do
    ! ! %p
    ! ! ! = elf.first_name
    kids/show.html.erb
    toys/_toy.html.erb
    elves/_elf.html.erb
    24
    

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26. 3
    - cache [ "v2", kid ] do
    %h1= "All toys for #{kid.name}"
    = render kid.toys
    ! - cache [ "v1", toy ] do
    %h2= toy.name
    ! = render toy.elves
    ! ! - cache [ "v1", elf ] do
    ! ! %p
    ! ! ! = elf.first_name
    kids/show.html.erb
    toys/_toy.html.erb
    elves/_elf.html.erb
    25
    

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27. 3
    - cache [ "v2", kid ] do
    %h1= "All toys for #{kid.name}"
    = render kid.toys
    ! - cache [ "v2", toy ] do
    %em= toy.build_on
    %h2= toy.name
    ! = render toy.elves
    ! ! - cache [ "v1", elf ] do
    ! ! %p
    ! ! ! = elf.first_name
    kids/show.html.erb
    toys/_toy.html.erb
    elves/_elf.html.erb
    26
    

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28. 3
    - cache [ "v3", kid ] do
    %h1= "All toys for #{kid.name}"
    = render kid.toys
    ! - cache [ "v2", toy ] do
    %em= toy.build_on
    %h2= toy.name
    ! = render toy.elves
    ! ! - cache [ "v1", elf ] do
    ! ! %p
    ! ! ! = elf.first_name
    kids/show.html.erb
    toys/_toy.html.erb
    elves/_elf.html.erb
    27
    

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29. 3
    - cache [ "v3", kid ] do
    %h1= "All toys for #{kid.name}"
    = render kid.toys
    ! - cache [ "v2", toy ] do
    %em= toy.build_on
    %h2= toy.name
    ! = render toy.elves
    ! ! - cache [ "v2", elf ] do
    ! ! %p
    ! ! ! = elf.first_name
    ! ! ! = elf.last_name
    kids/show.html.erb
    toys/_toy.html.erb
    elves/_elf.html.erb
    28
    

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30. 3
    - cache [ "v3", kid ] do
    %h1= "All toys for #{kid.name}"
    = render kid.toys
    ! - cache [ "v3", toy ] do
    %em= toy.build_on
    %h2= toy.name
    ! = render toy.elves
    ! ! - cache [ "v2", elf ] do
    ! ! %p
    ! ! ! = elf.first_name
    ! ! ! = elf.last_name
    kids/show.html.erb
    toys/_toy.html.erb
    elves/_elf.html.erb
    29
    

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31. 3
    - cache [ "v4", kid ] do
    %h1= "All toys for #{kid.name}"
    = render kid.toys
    ! - cache [ "v3", toy ] do
    %em= toy.build_on
    %h2= toy.name
    ! = render toy.elves
    ! ! - cache [ "v2", elf ] do
    ! ! %p
    ! ! ! = elf.first_name
    ! ! ! = elf.last_name
    kids/show.html.erb
    toys/_toy.html.erb
    elves/_elf.html.erb
    30
    

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32. 4
    https://github.com/rails/cache_digests
    31
    

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33. views/kids/45-20121211152602/d9fb66b120b61f46707c67ab41d93cb2
    MD5 hash of the template content
    and of all its dependencies
    4
    32
    

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34. 4
    - cache [ kid ] do
    %h1 All toys
    = render kid.toys
    ! - cache [ toy ] do
    %h2= toy.name
    ! = render toy.elves
    ! ! - cache [ elf ] do
    ! ! %p
    ! ! ! = elf.first_name
    kids/show.html.erb
    toys/_toy.html.erb
    elves/_elf.html.erb
    33
    

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35. 4
    - cache [ kid ] do
    %h1= "All toys for #{kid.name}"
    = render kid.toys
    ! - cache [ toy ] do
    %em= toy.build_on
    %h2= toy.name
    ! = render toy.elves
    ! ! - cache [ elf ] do
    ! ! %p
    ! ! ! = elf.first_name
    ! ! ! = elf.last_name
    kids/show.html.erb
    toys/_toy.html.erb
    elves/_elf.html.erb
    34
    

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36. Use it now!
    # gemfile
    gem 'cache_digests'
    3
    35
    

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37. and…
    4
    ActionController::Caching::Pages
    ActionController::Caching::Actions
    36
    

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38. and…
    4
    ActionController::Caching::Pages
    ActionController::Caching::Actions
    36
    

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39. and…
    4
    ActionController::Caching::Pages
    ActionController::Caching::Actions
    # gemfile
    gem 'actionpack-page_caching'
    # gemfile
    gem 'actionpack-action_caching'
    36
    

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40. turbolinks
    37
    

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41. • doesn’t re-load JS and CSS
    • doesn’t re-compile
    • page instance is kept alive
    • only the body and title of the page are
    replaced
    4
    38
    

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42. • doesn’t re-load JS and CSS
    • doesn’t re-compile
    • page instance is kept alive
    • only the body and title of the page are
    replaced
    4
    • response contains the full rendered
    page, so no bandwidth is saved
    38
    

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43. Gotchas
    $(document).ready( function() {
    ! …
    });
    39
    

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44. Gotchas
    3
    $(document).ready(function() {
    ! $("a.special_link").on("click", function(event) {
    ! ! alert('Christmas!!!');
    ! });
    });
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45. Gotchas
    3
    $(document).ready(function() {
    ! $("a.special_link").on("click", function(event) {
    ! ! alert('Christmas!!!');
    ! });
    });
    4
    $(document).ready(function() {
    ! $(document).on("click", "a.special_link", function(event) {
    ! ! alert('Christmas!!!');
    ! });
    });
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46. Turbolinks events
    page:fetch
    starting to fetch the target page (only called if loading fresh,
    not from cache).
    page:load fetched page is being retrieved fresh from the server
    page:restore
    fetched page is being retrieved from the 10-slot client-side
    cache
    page:change page has changed to the newly fetched version
    41
    

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47. $(document).ready(function() {
    ! $(document).on("click", "a.special_link", function(event) {
    ! ! alert('Christmas!!!');
    ! });
    });
    $(document).on("page:load" function() {
    ! $("a.special_link").on("click", function(event) {
    ! ! alert('Christmas!!!');
    ! });
    });
    4
    42
    

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48. Track asset changes 4
    type="text/css" data-turbolinks-track>
    43
    

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49. Don’t want turbolinks?
    4
    Articles
    44
    

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50. Use it now!
    https://github.com/rails/turbolinks
    45
    

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51. PATCH verb
    46
    

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52. • resource creation or replacement at some given URL
    • must send a complete representation of the resource
    • idempotent method (same request has always same result,
    think :updated_at)
    PUT
    47
    

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53. • not idempotent
    • allows full and partial updates
    • allows side-effects on other resources
    PATCH
    48
    

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54. PATCH
    • PATCH is going to be the primary method for updates in Rails 4.0
    • both PUT and PATCH are routed to update
    49
    

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55. match
    50
    

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56. • match respond to all HTTP verbs (POST,
    PUT, DELETE and GET)
    • potential cross site request forgery (CSRF)
    #match
    3
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57. match '/toys/:id/purchase' => 'toys#purchase'
    CSRF protection already exists in Rails but
    not for the GET method
    Problem
    3
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58. get '/toys/:id/purchase' => 'Toy#purchase'
    match '/toys/:id/purchase' => 'Toy#purchase', :via => :get
    match '/toys/:id/purchase' => 'Toy#purchase', :via => :any
    Rails4 forces a verb to be present on match
    routes
    Solution
    53
    

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59. concerns
    54
    

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60. # config/routes.rb
    Christmas::Application.routes.draw do
    ! resources :toys do
    ! ! resources :pictures
    ! end
    ! resources :kids do
    ! ! resources :pictures
    ! end
    ! resources :elves do
    ! ! resources :pictures
    ! end
    end
    Your routes are not DRY
    3
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61. # config/routes.rb
    Christmas::Application.routes.draw do
    ! concern :picturable do |options|
    ! ! resources :pictures, options
    ! end
    resources :toys, :concerns :picturable
    resources :kids, :concerns :picturable
    resources :elves, :concerns :picturable
    end
    Your routes are DRY
    4
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62. # config/routes.rb
    Christmas::Application.routes.draw do
    ! concern :picturable do
    ! ! resources :pictures
    ! end
    resources [:toys, :kids, :elves], :concerns :picturable
    end
    Your routes are DRY
    4
    57
    

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63. various
    58
    

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64. ActiveRecord::Relation
    59
    

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65. 3
    # toys_controller.rb
    def index
    ! if current_kid.good_kid?
    ! ! if current_kid.girl?
    ! ! ! @toys = Toy.for_girl
    ! ! else
    ! ! ! @toys = Toy.for_boy
    ! ! end
    ! else
    ! ! @toys = []
    ! end
    !
    …
    ! @toys = @toys.in_stock unless @toys.is_a?(Array)
    end
    60
    

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66. ActiveRecord::Relation#none
    # toys_controller.rb
    def index
    ! if current_kid.good_kid?
    ! ! if current_kid.girl?
    ! ! ! @toys = Toy.for_girl
    ! ! else
    ! ! ! @toys = Toy.for_boy
    ! ! end
    ! else
    ! ! @toys = Toy.none
    ! end
    !
    …
    ! @toys = @toys.in_stock
    end
    4
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67. ActiveRecord::Relation#all
    ActiveRecord::Relation#where!
    ActiveRecord::Relation#none!
    # toys_controller.rb
    def index
    ! @toys = Toy.all
    ! if current_kid.good_kid?
    ! ! if current_kid.girl?
    ! ! ! @toys.where!(girl: true)
    ! ! else
    ! ! ! @toys.where!(boy: true)
    ! ! end
    ! else
    ! ! @toys.none!
    ! end
    ! …
    ! @toys = @toys.in_stock
    end
    4
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68. ActiveRecord::Relation#not
    Item.where "kid_id != ?", current_kid.kid_id
    Item.where.not kid_id: current_kid.id
    4
    3
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69. ActiveRecord::Relation#order
    Toy.order("orders_count DESC").order(:created_at)
    # SELECT * FROM toys ORDER BY orders_count DESC, created_at
    3
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70. Toy.order("orders_count DESC").order(:created_at)
    # SELECT * FROM toys ORDER BY created_at, orders_count DESC
    4
    ActiveRecord::Relation#order
    65
    

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71. Toy.order("orders_count DESC").order(:created_at)
    # SELECT * FROM toys ORDER BY created_at, orders_count DESC
    4
    Comment.order("replies_count DESC", :created_at)
    ActiveRecord::Relation#order
    65
    

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72. deprecated finders
    3
    Item.find(:first, :conditions => ...) Item.where(...).first
    find_all_by_...
    scoped_by_...
    where(...)
    find_last_by_... where(...).last
    first_or_initialize_by_...
    first_or_initialize_by(...)
    find_or_create_by_... find_or_create_by(...)
    first_or_create_by_...! find_or_create_by!(...)
    4
    # Gemfile
    gem "activerecord-deprecated_finders"
    66
    

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73. class Order < ActiveRecord::Base
    ! scope :past, where("orders.sent_on < ?", Time.current)
    end
    scope
    3
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74. class Order < ActiveRecord::Base
    ! scope :past, where("orders.sent_on < ?", Time.current)
    end
    scope
    # DEPRECATION WARNING: Using #scope without passing a
    callable object is deprecated.
    4
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75. class Order < ActiveRecord::Base
    ! scope :past, ->{ where("orders.sent_on < ?", Time.current) }
    end
    scope
    4
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76. new form helpers
    collection_check_boxes(:toy, :category_ids, Category.all, :id, :name)
    # Returns:
    # # value="1" checked="checked" />
    # Ruby
    # # value="2" />
    # Javascript
    # ...
    #
    70
    

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77. new form helpers
    collection_radio_buttons(:toy, :category_ids, Category.all, :id, :name)
    # Returns:
    # checked="checked" />
    # Ruby
    # >
    # Javascript
    # ...
    71
    

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78. new form helpers
    collection_check_boxes(:toy, :category_ids, Category.all, :id, :name) do |b|
    b.label(:"data-value" => b.value) { b.check_box + b.text }
    end
    Customizable by a block
    72
    

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80. Install it today!
    • git clone git://github.com/rails/rails.git path_to/
    rails
    • path_to/rails/railties/bin/rails new AppName --edge
    74
    

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81. When?
    75
    

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82. When?
    75
    

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83. A few resources…
    76
    

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84. …for Christmas time!
    77
    

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85. Prepare to upgrade
    https://github.com/alindeman/rails4_upgrade
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86. presentations
    • rails 4 in 30 minutes (Santiago Pastorino)
    • slides: http://blog.wyeworks.com/2012/10/29/rails-4-in-30-minutes/
    • Rails 4.0 Whirlwind Tour (Andy Lindeman)
    • slides: https://speakerdeck.com/alindeman/rails-4-dot-0-whirlwind-tour
    • video: http://vimeo.com/51181496
    • What to Expect in Rails 4.0 (Prem Sichanugrist)
    • slides: https://speakerdeck.com/bostonrb/what-to-expect-in-rails-4-dot-0
    • video: http://www.youtube.com/watch?v=z6YgD6tVPQs
    • Why should I care about Rails 4? (Steve Klabnik)
    • slides: https://speakerdeck.com/steveklabnik/why-should-i-care-about-rails-4
    • video: http://vimeo.com/51898266
    • Rails 4 and the Future of Web (Aaron Patterson)
    • slides: https://speakerdeck.com/tenderlove/aloha-ruby-conference-2012
    • video: http://www.youtube.com/watch?v=kufXhNkm5WU
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