Rails Engines

A presentation about what are Rails Engines, how can they help you and when should you use them.

Transcript

1. Rails Engines
   Janko Marohnić
   janko-m @jankomarohnic
   

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2. ├── lib
   │ └── todo.rb
   └── todo.gemspec
   

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3. ├── lib
   │ └── todo.rb
   └── todo.gemspec
   ├── vendor
   ├── config
   ├── app
   

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4. lib/todo.rb
   module Todo
   # ...
   end
   module Todo
   class Engine < Rails::Engine
   end
   end
   

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5. ├── app
   │ └── views
   │ ├── assets
   │ ├── controllers
   │ ├── helpers
   │ ├── models
   ├── vendor
   │ └── assets
   ├── config
   │ └── locales
   ├── lib
   │ └── tasks
   │ ├── initializers
   

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6. Engine
   App
   Todo::Engine.routes.draw do
   resources :tasks
   end
   Todo::Engine.routes.draw do
   resources :tasks
   end
   Rails.application.routes.draw do
   mount Todo::Engine, at: “/todo”
   end
   

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7. $ rake routes
   Prefix Verb URI Pattern Controller#Action
   root GET / home#index
   about GET /about pages#about
   faq GET /terms pages#terms
   todo /todo Todo::Engine
   !
   Routes for Todo::Engine:
   tasks GET todo/tasks tasks#index
   POST todo/tasks tasks#create
   new_task GET todo/tasks/new tasks#new
   edit_task GET todo/tasks/:id/edit tasks#edit
   task GET todo/tasks/:id tasks#show
   PATCH todo/tasks/:id tasks#update
   PUT todo/tasks/:id tasks#update
   DELETE todo/tasks/:id tasks#destroy
   

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8. Engine
   App
   ├── db
   │ ├── migrate
   │ │ ├── 20140614100712_create_tasks.rb
   │ │ ├── 20140614100941_add_position_to_tasks.rb
   │ │ ├── 20140614101121_create_owners.rb
   $ rake todo:install:migrations
   ├── db
   │ ├── migrate
   │ │ ├── 20140614100712_create_tasks.todo.rb
   │ │ ├── 20140614100941_add_position_to_tasks.todo.rb
   │ │ ├── 20140614101121_create_owners.todo.rb
   

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9. Engine kao library
   

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10. Primjeri
    • Devise
    
    • ActiveAdmin
    
    • Spree
    
    • Kaminari
    

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11. Engine kao dio aplikacije
    

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12. Rails.application.routes.draw do
    root to: “pages#home”
    !
    controller :pages do
    get “/about”, to: :about
    get “/terms”, to: :terms
    end
    resources :songs
    end
    Rails.application.routes.draw do
    root to: “pages#home
    !
    controller :pages do
    get “/about”, to: :about
    get “/terms”, to: :terms
    end
    resources :songs
    !
    # LEGACY ROUTES #
    !
    get “/start” => redirect(“/”)
    get “/about-us” => redirect(“/about”)
    get “/home” => redirect(“/about”)
    resources :tracks, controller: :songs
    !
    get “/home/songs” => redirect(“/songs”)
    get “/authenticate” => “devise#login”
    get “/auth/google” => “/authenticate”
    get “/sign_in” => redirect(“/login”)
    

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13. ├── app
    ├── config
    ├── db
    ├── lib
    ├── script
    ├── vendor
    ├── public
    

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14. ├── app
    ├── config
    ├── db
    ├── lib
    ├── script
    ├── vendor
    ├── public
    ├── engines
    

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15. ├── app
    ├── config
    ├── db
    ├── lib
    ├── script
    ├── vendor
    ├── public
    ├── engines
    │ └── legacy
    

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16. ruby “2.1.2”
    !
    source “https://rubygems.org”
    !
    gem “rails”, “~> 4.1.1”
    gem “pg”
    !
    gem “legacy”, path: “engines/legacy”
    !
    group :assets do
    # …
    end
    Gemfile
    

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17. Engine
    App
    Rails.application.routes.draw do
    controller :pages do
    get “/about”, to: :about
    get “/terms”, to: :terms
    end
    resources :songs
    !
    !
    end
    Rails.application.routes.draw do
    controller :pages do
    get “/about”, to: :about
    get “/terms”, to: :terms
    end
    resources :songs
    !
    mount Legacy::Engine, at: “/”
    end
    Legacy::Engine.routes.draw do
    get “/start” => redirect(“/”)
    get “/about-us” => redirect(“/about”)
    get “/home” => redirect(“/about”)
    resources :tracks, controller: :songs
    end
    

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18. class ApplicationControler < ActionController::Base
    # …
    !
    private
    !
    def current_user
    User.find_by(id: session[:user_id])
    end
    !
    def authenticate!
    if not user_signed_in?
    redirect_to sign_in_path
    end
    end
    !
    # …
    end
    

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19. ├── app
    ├── config
    ├── db
    ├── lib
    ├── script
    ├── vendor
    ├── public
    ├── engines
    │ └── legacy
    

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20. ├── app
    ├── config
    ├── db
    ├── lib
    ├── script
    ├── vendor
    ├── public
    ├── engines
    │ └── legacy
    │ ├── authentication
    

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21. Engine
    App
    class AuthController < ApplicationController
    def authenticate!
    # …
    end
    !
    def current_user
    # …
    end
    end
    class ApplicationController < AC::Base
    before_filter :important_announcement
    !
    private
    !
    def important_announcement
    puts “Šime je glup”
    end
    end
    

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22. Izolirani Engine
    Todo
    Views
    Routes
    Helpers
    

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23. module Todo
    class Engine < Rails::Engine
    !
    end
    end
    module Todo
    class Engine < Rails::Engine
    isolate_namespace Todo
    end
    end
    Izolirani Engine
    

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24. Izolirani Engine
    todo.root_path
    todo.tasks_path
    todo.new_task_path
    URL helpers
    

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25. Izolirani Engine
    main_app.root_path
    main_app.about_path
    main_app.terms_path
    URL helpers
    

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26. Izolirani Engine
    Todo
    Views
    Routes
    Helpers
    

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27. Izolirani Engine
    Views
    Routes
    Helpers
    Todo
    

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28. Izolirani Engine
    Views
    Routes
    Helpers
    Authentication
    Legacy
    Todo
    Blog
    Marketing
    Mobile
    

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29. Rails::Engine
    Rails::Application
    Rails::Railtie
    

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30. Railtie
    initializers
    
    rake tasks
    

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31. Railtie
    Engine
    MVC
    
    routes
    initializers
    
    rake tasks
    

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32. Railtie
    Engine
    Application
    MVC
    
    routes
    initializers
    
    rake tasks
    booting
    
    initializing
    
    middleware
    

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33. Dokumentacija
    

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34. Engineovi su zakon
    Koristite ih, i radite svoje
    

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