Os truques que o Rails não te contou @ TDC Floripa 2014

Transcript

1. Os truques que o Rails não te contou
2. Carlos Antonio @cantoniodasilva
3. ~6 anos com Rails
4. Eu já participei em vários projetos com contextos diferentes
5. Eu já vi código
6. Eu já vi código complexo
7. Eu já vi código duplicado
8. Eu já vi código do Rails reimplementado em apps
9. Com que frequência você vê eles? Todo o tempo. Eles estão em toda parte.
10. Você se acostuma com o código após algum tempo
11. E isso é um grande problema As pessoas têm medo de lidar com esse tipo de código.
12. Rails tricks / features
13. Que podem te ajudar a refatorar código existente ou melhorar sua vida como desenvolvedor um pouquinho
16. Consultoria em Desenvolvimento Web Com foco principal em Ruby e Rails São Paulo - Brazil
17. ❤️
18. plataformatec/devise
19. plataformatec/simple_form
20. elixir-lang/elixir
21. Rails Core Team ! Carlos Antonio
22. Rails Core Team José Valim Carlos Antonio Rafael França
23. Nós usamos pull requests ! e code review All the f*cking time.
24. Nós fizemos code review de diferentes projetos Sempre que o tempo nos permite.
25. E é comum aprender coisas novas no processo Estamos sempre aprendendo, certo?
31. ಠ_ಠ Eu tive que criar este talk depois disso.
32. Rails tricks / features Não usadas por muitos Não muito conhecidas e / ou documentadas
33. O que vamos ver: Active Record Active Model Action Mailer Action View Action Controller Bonus Stuff
34. Active Record
35. migrations: 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
36. migrations: 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
37. migrations: change column null class ChangeNameToNotNullOnAuthors < ActiveRecord::Migration def change change_column :authors, :name, :string, null: false end end # => ActiveRecord::IrreversibleMigration ! class ChangeNameToNotNullOnAuthors < ActiveRecord::Migration def change change_column_null :authors, :name, false end end
38. migrations: 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
39. migrations: change column default class ChangeStatusDefaultOnArticles < ActiveRecord::Migration def up change_column_default :articles, :status, 'draft' end ! def down change_column_default :articles, :status, 'published' end end
40. migrations: change column default class ChangeStatusDefaultOnArticles < ActiveRecord::Migration def change change_column :articles, :status, :string, default: 'draft' end end # => ActiveRecord::IrreversibleMigration ! class ChangeStatusDefaultOnArticles < ActiveRecord::Migration def change change_column_default :articles, :status, 'draft' end end # => ActiveRecord::IrreversibleMigration
41. Relation#merge class Author < ActiveRecord::Base has_many :articles ! scope :with_draft_articles, -> { uniq.joins(:articles). where(articles: { status: 'draft' }) } end
42. Relation#merge >> Author.with_draft_articles.to_sql ! SELECT DISTINCT "authors".* FROM "authors" INNER JOIN "articles" ON "articles"."author_id" = "authors"."id" WHERE "articles"."status" = 'draft'
43. Relation#merge class Author < ActiveRecord::Base has_many :articles ! scope :with_draft_articles, -> { uniq.joins(:articles).merge(Article.draft) } end
44. Relation#merge >> Author.with_draft_articles.to_sql ! SELECT DISTINCT "authors".* FROM "authors" INNER JOIN "articles" ON "articles"."author_id" = "authors"."id" WHERE "articles"."status" = 'draft'
45. group counting >> Article.group(:status).count ! SELECT COUNT(*) AS count_all, status AS status FROM "articles" GROUP BY status ! => {"draft"=>7, "published"=>2}
46. group counting: múltiplos atributos >> Article.group(:status, :category).count ! SELECT COUNT(*) AS count_all, status AS status, category AS category FROM "articles" GROUP BY status, category ! => {["draft", nil]=>5, ["draft", "Talks"]=>2, ["published", "News"]=>1, ["published", "Releases"]=>1}
47. first! relation = Article.where(title: 'UNKNOWN') ! relation.first or raise(ActiveRecord::RecordNotFound, 'ZOMG not found') # => ZOMG Article found (ActiveRecord::RecordNotFound) ! relation.first! # => ActiveRecord::RecordNotFound
48. last! relation = Article.where(title: 'UNKNOWN') ! relation.last or raise(ActiveRecord::RecordNotFound, 'ZOMG not found') # => ZOMG Article found (ActiveRecord::RecordNotFound) ! relation.last! # => ActiveRecord::RecordNotFound
49. 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')
50. 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')
51. estratégias de eager load >> Article.includes(:author) ! SELECT "articles".* FROM "articles" ! SELECT "authors".* FROM "authors" WHERE "authors"."id" IN (980190962, 298486374)
52. estratégias de eager load >> Article.includes(:author).order('authors.name') ! SELECT "articles"."id" AS t0_r0 ………… "authors"."updated_at" AS t1_r4 FROM "articles" LEFT OUTER JOIN "authors" ON "authors"."id" = “articles"."author_id" ORDER BY authors.name
53. estratégias de eager load >> Article.eager_load(:author) ! SELECT "articles"."id" AS t0_r0 ………… "authors"."updated_at" AS t1_r4 FROM “articles" LEFT OUTER JOIN "authors" ON "authors"."id" = “articles"."author_id"
54. estratégias de eager load >> Article.preload(:author) ! SELECT "articles".* FROM “articles" ! SELECT "authors".* FROM “authors" WHERE "authors"."id" IN (980190962, 298486374)
55. estratégias de eager load >> Article.preload(:author).joins(:author).order('authors.name') ! SELECT "articles".* FROM "articles" INNER JOIN "authors" ON "authors"."id" = "articles"."author_id" ORDER BY authors.name ! SELECT "authors".* FROM "authors" WHERE "authors"."id" IN (980190962, 298486374)
56. 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
57. 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
58. pluck >> Author.all.map(&:name) ! SELECT "authors".* FROM "authors" ! => ["Author 2", "Author 1"]
59. pluck >> Author.select(:name).map(&:name) ! SELECT "authors"."name" FROM "authors" ! => ["Author 2", "Author 1"]
60. pluck >> Author.pluck(:name) ! SELECT "authors"."name" FROM "authors" ! => ["Author 2", "Author 1"]
61. pluck: múltiplos atributos >> Author.pluck(:name, :active) ! SELECT "authors"."name", "authors"."active" FROM "authors" ! => [["Author 2", true], ["Author 1", true]]
62. pluck: valores distintos >> Author.distinct.pluck(:name) ! SELECT DISTINCT "authors"."name" FROM "authors" ! => ["Author 2", "Author 1"]
63. to_param class Article < ActiveRecord::Base def to_param "#{id}-#{title.parameterize}" end end ! >> Article.all.map(&:to_param) => ["113629430-autoload", "281110143-rails-4-2-0-is-going-to-be-more-adequate", "298486374-rails-4-1-0-released", "980190962-rails-tricks"]
64. to_param class Article < ActiveRecord::Base to_param :title end ! ! ! >> Article.all.map(&:to_param) => ["113629430-autoload", "281110143-rails-4-2-0-is", "298486374-rails-4-1-0-released", "980190962-rails-tricks"]
65. exists?/any? vs present? <% if @author.articles.exists? %> <%= render @author.articles %> <% else %> <p>No article found.</p> <% end %>
66. exists?/any? vs present? >> author = Author.first ! >> author.articles.exists? ! SELECT 1 AS one FROM "articles" WHERE "articles"."author_id" = ? LIMIT 1 [["author_id", 298486374]] ! => true ! >> author.articles.each {} ! SELECT "articles".* FROM "articles" WHERE "articles"."author_id" = ? [["author_id", 298486374]]
67. exists?/any? vs present? >> author = Author.first ! >> author.articles.present? ! SELECT "articles".* FROM "articles" WHERE "articles"."author_id" = ? [["author_id", 298486374]] ! => true ! >> author.articles.each {} ! # => already loaded, so no query
68. benchmark class Article < ActiveRecord::Base def self.expensive_operation sleep 2 'did something very expensive' end end
69. benchmark >> start = Time.now => 2014-04-21 10:48:30 -0500 >> Article.expensive_operation => "did something very expensive" >> finish = Time.now => 2014-04-21 10:48:32 -0500 >> finish - start => 2.02356
70. benchmark >> ActiveRecord::Base.benchmark 'SUPER EXPENSIVE OPERATION' do ?> Article.expensive_operation >> end SUPER EXPENSIVE OPERATION (2000.9ms) => "did something very expensive"
71. benchmark class Article < ActiveRecord::Base def self.expensive_operation benchmark 'SUPER EXPENSIVE OPERATION' do sleep 2 'did something very expensive' end end end
73. http://railsgirlssummerofcode.org/campaign/ Free hug!
74. Active Model
75. ActiveModel::Model class EmailContact attr_accessor :name, :email, :message ! def deliver if name.present? && email.present? && message.present? puts 'deliver email' end end end
76. ActiveModel::Model contact = EmailContact.new contact.name = 'Carlos' contact.email = 'carlos@example.com' contact.message = 'ZOMG' contact.deliver
77. ActiveModel::Model <%= form_for @email_contact … %> ! <%= render @email_contact %>
78. ActiveModel::Model class EmailContact extend ActiveModel::Naming extend ActiveModel::Translation include ActiveModel::Validations include ActiveModel::Conversion ! attr_accessor :name, :email, :message validates :name, :email, :message, presence: true ! def deliver if valid? puts 'deliver email' end end ! def persisted? false end end
79. ActiveModel::Model class EmailContact include ActiveModel::Model ! attr_accessor :name, :email, :message validates :name, :email, :message, presence: true ! def deliver if valid? puts 'deliver email' end end end
80. ActiveModel::Model contact = EmailContact.new( name: 'Carlos', email: 'carlos@example.com', message: 'ZOMG' ) contact.deliver
81. ActiveModel::Model >> contact = EmailContact.new => #<EmailContact:0x007fb90e268350> ! >> contact.valid? => false ! >> contact.errors.full_messages.to_sentence => "Name can't be blank, Email can't be blank, and Message can't be blank"
82. Action Mailer
83. Mailer com 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
84. Mailer com 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
85. Mailer com i18n subject en: subjects: new_article: 'New article just published.'
86. Mailer com i18n subject en: notifier: new_article: subject: 'New article just published.'
87. Mailer com i18n subject class Notifier < ActionMailer::Base default from: "from@example.com" ! def new_article @greeting = "Hi" ! mail to: "to@example.org" end end
88. Mailer com 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', title: 'Clarity is king') end end
89. Mailer com i18n subject en: subjects: new_article: 'New article: %{title}.'
90. Mailer com i18n subject en: notifier: new_article: subject: 'New article %{title}.'
91. Mailer com 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
92. Action View
93. content_tag_for <%= content_tag_for :article, @articles do |article| %> <h2><%= article.title %></h2> <%= simple_format article.body %> <% end %>
94. content_tag_for <article class="article" id="article_281110143"> <h2>Rails 4.2.0 is going to be more Adequate</h2> <p>Rails 4.2.0 is going to be made more Adequate by Tenderlove and Gorby Puff</p> </article> <article class="article" id="article_298486374"> <h2>Rails 4.1.0 Released</h2> <p>Rails 4.1.0 was just released before RailsConf</p> </article>
95. content_tag_for <%= content_tag_for :section, @author do |author| %> <h1><%= author.name %></h1> … <% end %>
96. content_tag_for <section class="author" id="author_298486374"> <h1>Author 2</h1> … </section>
97. render com coleções vazias <% if author.articles.exists? %> <%= render author.articles %> <% else %> <p>No article found.</p> <% end %>
98. render com coleções vazias <%= render(author.articles) || content_tag(:p, 'No article found.') %>
99. partial locals <%= render article, full: true %> <%= render author.articles, full: false %> ! # article partial <%= content_tag_for :article, article do |article| %> <h2><%= article.title %></h2> ! <% if full %> <%= simple_format article.body %> <% else %> <%= truncate article.body %> <% end %> <% end %>
100. partial locals <%= render article, full: true %> <%= render author.articles %> ! # article partial <%= content_tag_for :article, article do |article| %> <h2><%= article.title %></h2> ! <% if local_assigns[:full] %> <%= simple_format article.body %> <% else %> <%= truncate article.body %> <% end %> <% end %>
101. truncar textos <%= truncate article.body do %> <%= link_to 'read more...', article %> <% end %> ! ! Rails 4.2.0 is going to be ... <a href="/articles/281110143-rails-4-2-0-is"> read more… </a>
102. I18n + html <%= link_to I18n.t('read_more'), article %> ! ! en: read_more: 'read more…' ! ! <a href="/articles/281110143-rails-4-2-0-is"> read more… </a>
103. I18n + html <%= link_to I18n.t('read_more'), article %> ! ! en: read_more: 'read <b>more</b>…' ! ! <a href="/articles/281110143-rails-4-2-0-is"> read &lt;b&gt;more&lt;/b&gt;… </a>
104. I18n + html <%= link_to raw(I18n.t('read_more')), article %> ! ! en: read_more: 'read <b>more</b>…' ! ! <a href="/articles/281110143-rails-4-2-0-is"> read <b>more</b>… </a>
105. I18n + html <%= link_to I18n.t(‘read_more_html'), article %> ! ! en: read_more_html: 'read <b>more</b>…' ! ! <a href="/articles/281110143-rails-4-2-0-is"> read <b>more</b>… </a>
106. benchmark <% benchmark 'Rendering articles' do %> <%= sleep(2); render author.articles %> <% end %> ! ! # logger Rendering articles (2005.1ms)
107. Action Controller
108. redirects com parâmetros get '/articles/:id' => redirect('/articles/%{id}/edit')
109. tratamento de exceções $ ls public/*.html ! 404.html 422.html 500.html
110. tratamento de exceções # config/application.rb ! # Use the app's own router to display error pages. config.exceptions_app = self.routes
111. tratamento de exceções # config/routes.rb ! get "/404", to: "errors#not_found" get "/422", to: "errors#unprocessable_entity" get "/500", to: "errors#server_error"
112. tratamento de exceções class ErrorsController < ApplicationController layout "error" ! def not_found render status: :not_found end ! def server_error render status: :server_error end ! def unprocessable_entity render status: :unprocessable_entity end end
113. tratamento de exceções app/views/ errors/ not_found.html.erb server_error.html.erb unprocessable_entity.html.erb layouts/ error.html.erb
114. Bonus Time!
115. Console
116. app >> app.author_path(Author.first) => “/authors/298486374" ! >> app.get _ Started GET "/authors/298486374" for 127.0.0.1 at 2014-04-22 19:31:04 -0500 Processing by AuthorsController#show as HTML … Rendered authors/show.html.erb within layouts/application (1.1ms) Completed 200 OK in 9ms (Views: 7.7ms | ActiveRecord: 0.2ms) => 200 ! >> app.class => ActionDispatch::Integration::Session
117. helper >> helper.time_ago_in_words 30.days.ago => "about 1 month" ! >> helper.hello_rails_conf => "Hello RailsConf 2014!" ! >> helper.class => ActionView::Base
118. console helpers da aplicação # lib/console_helpers.rb module ConsoleHelpers def a(id) Article.find(id) end end
119. console helpers da aplicação # config/application.rb module RailsConf2014 class Application < Rails::Application console do require 'console_helpers' Rails::ConsoleMethods.send :include, ConsoleHelpers end end end
120. console helpers da aplicação >> a(113629430) Article Load (0.1ms) SELECT "articles".* FROM "articles" WHERE "articles"."id" = ? LIMIT 1 [["id", 113629430]] ! => #<Article id: 113629430, …>
121. console sandbox $ rails console >> Article.count => 4 ! $ rails console --sandbox >> Article.create! title: 'I will be rolled back' => #<Article id: 980190968, title: "I will be rolled back", …> >> Article.count => 5 ! $ rails console >> Article.count => 4
122. console sandbox $ rails console --sandbox … Any modifications you make will be rolled back on exit ! ! ! >> exit rollback transaction
123. Annotations
124. notas class Author < ActiveRecord::Base # TODO: create inactive scope scope :active, -> { where active: true } end ! class Article < ActiveRecord::Base # FIXME: Fix this scope :published, -> { where status: 'published' } end ! class AuthorsController < ApplicationController # OPTIMIZE: eager load stuff def show @author = Author.find(params[:id]) end end
125. notas $ rake notes ! app/controllers/authors_controller.rb: * [2] [OPTIMIZE] eager load stuff ! app/models/article.rb: * [9] [FIXME] Fix this ! app/models/author.rb: * [4] [TODO] create inactive scope
126. notas personalizadas class Notifier < ActionMailer::Base # ZOMG: Hello! def new_article end end
127. notas personalizadas $ rake notes:custom ANNOTATION=ZOMG ! app/mailers/notifier.rb: * [4] Hello!
128. Atualizando Rails
129. rails update gem 'rails', '4.1.0' ! ! $ bundle update …
130. rails update $ rake rails:update identical config/boot.rb exist config conflict config/routes.rb ./railsconf2014-404/config/routes.rb? (enter "h" for help) [Ynaqdh] h Y - yes, overwrite n - no, do not overwrite a - all, overwrite this and all others q - quit, abort d - diff, show the differences between the old and the new h - help, show this help ./railsconf2014-404/config/routes.rb? (enter "h" for help) [Ynaqdh] a force config/routes.rb … exist config/initializers identical config/initializers/backtrace_silencers.rb create config/initializers/cookies_serializer.rb identical config/initializers/filter_parameter_logging.rb …
131. rails update $ git status On branch master Changes not staged for commit: (use "git add <file>..." to update what will be committed) (use "git checkout -- <file>..." to discard changes in working directory) ! modified: Gemfile modified: Gemfile.lock modified: config/environment.rb modified: config/environments/development.rb modified: config/environments/production.rb modified: config/environments/test.rb modified: config/initializers/mime_types.rb modified: config/initializers/session_store.rb modified: config/routes.rb ! Untracked files: (use "git add <file>..." to include in what will be committed) ! config/initializers/cookies_serializer.rb config/secrets.yml
132. Cada parte do Rails tem seus truques escondidos
133. Eles são às vezes difíceis de achar
134. Mas eles podem te deixar muito mais produtivo
135. Então toda vez que você começar algo novo
136. Antes mesmo de considerar usar o pattern X, Y ou Z
137. Pergunte-se: Como o Rails pode me ajudar?
138. Pesquise API Guidelines Google Stack Overflow …
139. Pergunte Stack Overflow Rails Talk mailing list IRC …
140. Siga Changelogs Release Notes Upgrading Guides Commits (se puder)
141. E se você encontrar algum truque escondido, lembre-se…
142. With great moustache! ! ! ! comes great responsibility
143. Compartilhe Tweet Blog post Diga aos seus amigos …
144. Contribua De volta para o Rails
145. E por favor me avise! :) ! @cantoniodasilva
146. Os truques que o Rails não te contou Carlos Antonio - @cantoniodasilva