Tricks that Rails didn't tell you.

Some Rails tricks to help your productivity.

Transcript

1. TRICKS THAT RAILS DIDN’T TELL YOU
2. disclaimer
3. Carlos Antonio RailsConfchicago RubyConfsão paulo
6. TRICKS THAT RAILS DIDN’T TELL YOU
7. TRICKS THAT CARLOS DIDN’T TELL YOU
8. Who am I?
9. Kassio Borges kassio! kassioborgesm
10. ~9 yearsIT
11. Coffee Boy! Support! Deployment! Trainer! Developer
12. ~5 yearson Rails
14. Web Development Consultancy! Ruby and Rails! São Paulo
15. ❤️
16. plataformatec/devise
17. plataformatec/simple_form
18. elixir-lang/elixir elixir-lang.org
19. TRICKS THAT RAILS DIDN’T TELL YOU
20. ~5 yearson Rails
21. I’ve written code
22. I’ve written good code
23. I’ve written bad code
24. I’ve written duplicated code
25. I’ve rewritten some Rails code
26. SOME RAILS TRICKS! are not very well know and/or documented
27. TRICKS THAT RAILS DIDN’T TELL YOU
28. ActiveRecord! ActiveModel! ActionView! ActionMailer! ActionController! ActiveSupport
29. ActiveRecord! ActiveModel! ActionView! ActionMailer! ActionController! ActiveSupport
30. change column null class ChangeNameToNotNullOnAuthors < ActiveRecord::Migration def up change_column :authors, :name, :string, null: false end ! def down change_column :authors, :name, :string, null: true end end
31. change column null class ChangeNameToNotNullOnAuthors < ActiveRecord::Migration def up change_column_null :authors, :name, false end ! def down change_column_null :authors, :name, true end end
32. change column null class ChangeNameToNotNullOnAuthors < ActiveRecord::Migration def change change_column_null :authors, :name, false end end ! class ChangeNameToNotNullOnAuthors < ActiveRecord::Migration def change change_column :authors, :name, :string, null: false end end # => ActiveRecord::IrreversibleMigration
33. change column default class ChangeStatusDefaultOnArticles < ActiveRecord::Migration def up change_column :articles, :status, :string, default: 'draft' end ! def down change_column :articles, :status, :string, default: 'published' end end
34. change column default class ChangeStatusDefaultOnArticles < ActiveRecord::Migration def change change_column_default :articles, :status, 'draft' end end
35. change column default class ChangeStatusDefaultOnArticles < ActiveRecord::Migration def change change_column_default :articles, :status, 'draft' end end # => ActiveRecord::IrreversibleMigration ! class ChangeStatusDefaultOnArticles < ActiveRecord::Migration def change change_column :articles, :status, :string, default: 'draft' end end # => ActiveRecord::IrreversibleMigration
36. where.not class Article < ActiveRecord::Base scope :not_draft, -> { where 'status <> draft' } end ! >> Article.not_draft.to_sql SELECT "articles".* FROM "articles" WHERE (status != 'draft')
37. where.not class Article < ActiveRecord::Base scope :not_draft, -> { where.not status: 'draft' } end ! >> Article.not_draft.to_sql SELECT "articles".* FROM "articles" WHERE ("articles"."status" != 'draft')
38. order: :asc/:desc class Article < ActiveRecord::Base scope :recent, -> { order 'created_at DESC' } end ! >> Article.recent SELECT "articles".* FROM "articles" ORDER BY created_at DESC
39. order: :asc/:desc class Article < ActiveRecord::Base scope :recent, -> { order created_at: :desc } end ! >> Article.recent SELECT "articles".* FROM "articles" ORDER BY "articles"."created_at" DESC
40. pluck >> Author.all.map(&:name) SELECT "authors".* FROM "authors" ! => ["Author 2", "Author 1"]
41. pluck >> Author.select(:name).map(&:name) SELECT "authors"."name" FROM "authors" ! => ["Author 2", "Author 1"]
42. pluck >> Author.pluck(:name) SELECT "authors"."name" FROM "authors" ! => ["Author 2", "Author 1"]
43. pluck >> Author.pluck(:name, :active) SELECT "authors"."name", "authors"."active" FROM "authors" ! => [["Author 2", true], ["Author 1", true]]
44. benchmark class Article < ActiveRecord::Base def self.expensive_operation sleep 2 'did something very expensive' end end ! >> start = Time.now; Article.expensive_operation; Time.now - start => 2.001179
45. benchmark class Article < ActiveRecord::Base def self.expensive_operation benchmark 'SUPER EXPENSIVE OPERATION' do sleep 2 'did something very expensive' end end end ! >> Article.expensive SUPER EXPENSIVE OPERATION (2001.2ms)
46. ActiveRecord! ActiveModel! ActionView! ActionMailer! ActionController! ActiveSupport
47. ActiveRecord! ActiveModel! ActionView! ActionMailer! ActionController! ActiveSupport
48. validates strict class Comment include ActiveModel::Validations ! attr_accessor :message ! validates :message, presence: true, strict: true end ! >> Comment.new.valid? # ActiveModel::StrictValidationFailed: Message can't be blank
49. validates strict class Comment include ActiveModel::Validations ! attr_accessor :message validate do |comment| if message.blank? errors.add(:base, 'You need a message!') end end end ! >> Comment.new.valid? # false
50. validates strict class Comment include ActiveModel::Validations ! attr_accessor :message validate do |comment| if message.blank? errors.add(:base, 'You need a message!', strict: true) end end end ! > Comment.new.valid? # ActiveModel::StrictValidationFailed: You need a message!
51. ActiveRecord! ActiveModel! ActionView! ActionMailer! ActionController! ActiveSupport
52. ActiveRecord! ActiveModel! ActionView! ActionMailer! ActionController! ActiveSupport
53. menu links <li> <%= link_to 'posts', posts_path, class: active?(posts_path) %> </li> <li> <%= link_to 'new post', new_post_path, class: active?(new_post_path) %> </li>
54. menu links module ApplicationHelper def active?(path) if request.path == path 'active' end end end
55. menu links module ApplicationHelper def active?(*page) if current_page?(page) 'active' end end end
56. menu links <li> <%= link_to 'posts', posts_path, class: active?(posts_path) %> </li> <li> <%= link_to 'new post', new_post_path, class: active?(new_post_path) %> </li>
57. menu links <li> <%= link_to_unless current_path?(posts_path), 'posts', posts_path %> </li> <li> <%= link_to_unless current_path?(new_post_path), 'new post', new_post_path %> </li>
58. menu links <li><%= link_to_unless_current 'posts', posts_path %></li> <li><%= link_to_unless_current 'new post', new_post_path %></li>
59. I18n + html <%= link_to t('read_more'), article %> ! <a href="/articles/281110143-rails-4-2-0-is"> read more </a> en: read_more: 'read more'
60. I18n + html <%= link_to t('read_more'), article %> ! <a href="/articles/281110143-rails-4-2-0-is"> read &lt;b&gt;more&lt;/b&gt; </a> en: read_more: 'read <b>more</b>'
61. I18n + html en: read_more: 'read <b>more</b>' <%= link_to raw(t('read_more')), article %> ! <a href="/articles/281110143-rails-4-2-0-is"> read <b>more</b> </a>
62. I18n + html en: read_more_html: 'read <b>more</b>' <%= link_to t('read_more_html'), article %> ! <a href="/articles/281110143-rails-4-2-0-is"> read <b>more</b> </a>
63. benchmark <% start = Time.now %> <%= sleep(2); render 'form' %> <% Rails.logger.info("EXPENSIVE VIEW #{Time.now - start}") %> ! ! # logger # Rendered posts/_form.html.erb (2.5ms) # EXPENSIVE VIEW 2.003919
64. benchmark <% benchmark 'EXPENSIVE VIEW' do %> <%= sleep(2); render 'form' %> <% end %> ! ! # logger # Rendered posts/_form.html.erb (2.3ms) # EXPENSIVE VIEW (2004.5ms)
65. ActiveRecord! ActiveModel! ActionView! ActionMailer! ActionController! ActiveSupport
66. ActiveRecord! ActiveModel! ActionView! ActionMailer! ActionController! ActiveSupport
67. I18n subject class Notifier < ActionMailer::Base default from: "from@example.com" ! # Subject can be set in your I18n file at config/locales/en.yml # with the following lookup: # # en.notifier.new_article.subject # def new_article @greeting = "Hi" ! mail to: "to@example.org" end end
68. I18n subject class Notifier < ActionMailer::Base default from: "from@example.com" ! # Subject can be set in your I18n file at config/locales/en.yml # with the following lookup: # # en.notifier.new_article.subject # def new_article @greeting = "Hi" ! mail to: "to@example.org" end end
69. I18n subject class Notifier < ActionMailer::Base default from: "from@example.com" ! def new_article @greeting = "Hi" ! mail to: "to@example.org" end end
70. I18n subject class Notifier < ActionMailer::Base default from: "from@example.com" ! def new_article @greeting = "Hi" ! mail to: "to@example.org", subject: I18n.t('subjects.new_article') end end en: subjects: new_article: 'New article just published.'
71. I18n subject class Notifier < ActionMailer::Base default from: "from@example.com" ! def new_article @greeting = "Hi" ! mail to: "to@example.org" end end en: notifier: new_article: subject: 'New article just published.'
72. I18n subject en: subjects: new_article: 'New article: %{title}.' def new_article @greeting = "Hi" ! mail to: "to@example.org", subject: I18n.t('subjects.new_article', title: 'Clarity is king') end
73. I18n subject class Notifier < ActionMailer::Base default from: "from@example.com" ! def new_article @greeting = "Hi" ! mail to: "to@example.org", subject: default_i18n_subject(title: 'Clarity is king') end end en: notifier: new_article: subject: 'New article: %{title}.'
74. ActiveRecord! ActiveModel! ActionView! ActionMailer! ActionController! ActiveSupport
75. ActiveRecord! ActiveModel! ActionView! ActionMailer! ActionController! ActiveSupport
76. exceptions handling # exceptions handling ! $ ls public/*.html ! 404.html 422.html 500.html
77. exceptions handling # config/application.rb ! # Use the app's own router to display error pages. config.exceptions_app = self.routes
78. exceptions handling # config/routes.rb ! get "/404", to: "errors#not_found" get "/422", to: "errors#unprocessable_entity" get "/500", to: "errors#server_error"
79. exceptions handling class ErrorsController < ApplicationController layout "error" ! def not_found render status: :not_found end ! # ... end
80. ActiveRecord! ActiveModel! ActionView! ActionMailer! ActionController! ActiveSupport
81. ActiveRecord! ActiveModel! ActionView! ActionMailer! ActionController! ActiveSupport
82. index_by /authors /posts [ { "id": 1, "name": "d4rth_v4der" }, { "id": 2, "name": "luke_skywalk3r" }, { "id": 3, "name": "han_solo" } ] [ { "text": "@luke, I am your father!", "author": 1 }, { "text": "NOOOOOOOOOOOOO!! (╯°□°)╯︵ ┻━┻", "author": 2 }, { "text": "@luke “ ƅϪƅ“)", "author": 3 } ]
83. index_by @luke, I am your father!! d4rth_v4der! ---! NOOOOOOOOOOOOOOO!! (╯°□°)╯︵ ┻━┻! luke_skywalk3r! ---! @luke “ ƅϪƅ“)! han_solo! ---
84. index_by posts.each do |post| author = authors.select do |a| a.id == post.author end.first ! puts post.text puts author.name puts '---' end
85. index_by N*M 10*10 = 100
86. index_by posts.each do |post| author = indexed_authors[post.author] ! puts post.text puts author.name puts '---' end indexed_author = { 1=>#<Author id=1, name="Kassio Borges">, 2=>#<Author id=2, name="Boring">, }
87. index_by N+M 10+10 = 20
88. index_by indexed_author = { 1=>#<Author id=1, name="Kassio Borges">, 2=>#<Author id=2, name="Boring">, }
89. index_by indexed_authors = authors.inject({}) do |mem, author| mem[author.id] = author mem end
90. index_by indexed_authors = authors.each_with_object({}) do |author, mem| mem[author.id] = author end
91. index_by indexed_authors = authors.index_by(&:id)
92. ActiveRecord! ActiveModel! ActionView! ActionMailer! ActionController! ActiveSupport
93. Finishing
94. Every single part of Rails! has hidden tricks
95. Sometimes they are! hard to spot
96. But they can make you much more productive
97. So every time you start something new
98. Before ever considering about pattern X, Y or Z
99. Ask yourself:
 How Rails can help me?
100. Search! • API! • Guidelines! • IRC! • Rails Talk mailing list! • Stack Overflow
101. Follow! • Changelogs! • Release notes! • Upgrading guides! • Commits (if you can)
102. And if you find some hidden trick, remember
103. With a great moustache! cames a great responsibility
104. Share! • Tweet! • Blog post! • Tell your friends! • Talk at RuPy
105. Contribute back to Rails
106. And please,! tell me what you found! kassio! kassioborgesm
107. Thanks! kassio! kassioborgesm