Web development that hurts even less: taking lessons from Rails

It has been over ten years since the Rails framework brought Ruby to the forefront of web development. You might think Ruby is synonymous to Rails, but there’s more to the community than that. New languages and frameworks are no longer aiming to merely imitate Ruby and Rails — they are aiming to improve upon it. Lotus, ROM, Phoenix, Ecto, Sequel, Roda, Webpack: they all represent lessons learned about how we build software. It’s time to broaden our horizon (even if only a little bit). As good as Rails is, can we do better?

Transcript

1. View Slide

2. Arjan van der Gaag
   @avdgaag
   arjanvandergaag.nl
   brightin.nl
   

   View Slide

3. Web development that
   hurts even less
   Taking lessons from Rails
   

   View Slide

4. View Slide

5. “Look at all the code I’m
   not writing!”
   

   View Slide

6. “So that's why I love software. It's
   not like modern art. You can't just
   keep spouting intellectual nonsense
   forever. At the end of the day, you
   have to translate your prescriptions
   into running code and that's when
   the bullshit meter activates.”
   

   View Slide

7. Thanks, great discussion.
   

   View Slide

8. “Rails 5 is going to ship
   also with an evented file
   system monitor.”
   

   View Slide

9. (˽°□°҂˽Ɨ ˍʓˍ)
   

   View Slide

10. View Slide

11. View Slide

12. class ArticlesController <
    ApplicationController
    def show
    @article = Article
    .where.not(published_at: nil)
    .find(params[:id])
    end
    end
    

    View Slide

13. class ArticlesController <
    ApplicationController
    def show
    @article = Article
    .where.not(published_at: nil)
    .find(params[:id])
    end
    end
    

    View Slide

14. class ArticlesController <
    ApplicationController
    def show
    @article = Article
    .where.not(published_at: nil)
    .find(params[:id])
    end
    end
    

    View Slide

15. class ArticlesController <
    ApplicationController
    def show
    @article = Article
    .where.not(published_at: nil)
    .find(params[:id])
    end
    end
    

    View Slide

16. class ArticlesController <
    ApplicationController
    def show
    @article = Article
    .where.not(published_at: nil)
    .find(params[:id])
    end
    end
    

    View Slide

17. class ArticlesController <
    ApplicationController
    def show
    @article = Article
    .where.not(published_at: nil)
    .find(params[:id])
    end
    end
    

    View Slide

18. class ArticlesController <
    ApplicationController
    def show
    @article = Article
    .where.not(published_at: nil)
    .find(params[:id])
    end
    end
    

    View Slide

19. class ArticlesController <
    ApplicationController
    def show
    @article = Article
    .where.not(published_at: nil)
    .find(params[:id])
    end
    end
    

    View Slide

20. module Web::Controllers::Articles
    class Show
    include Web::Action
    expose :article
    def call(params)
    @article = ArticleRepository
    .published
    .find(params[:id])
    end
    end
    end
    

    View Slide

21. module Web::Controllers::Articles
    class Create
    include Web::Action
    expose :article
    def call(params)
    @article = ArticleRepository
    .published
    .find(params[:id])
    end
    end
    end
    

    View Slide

22. module Web::Controllers::Articles
    class Create
    include Web::Action
    expose :article
    def call(params)
    @article = ArticleRepository
    .published
    .find(params[:id])
    end
    end
    end
    

    View Slide

23. module Web::Controllers::Articles
    class Create
    include Web::Action
    expose :article
    def call(params)
    @article = ArticleRepository
    .published
    .find(params[:id])
    end
    end
    end
    

    View Slide

24. module Web::Controllers::Articles
    class Create
    include Web::Action
    expose :article
    def call(params)
    @article = ArticleRepository
    .published
    .find(params[:id])
    end
    end
    end
    

    View Slide

25. module Web::Controllers::Articles
    class Create
    include Web::Action
    expose :article
    def call(params)
    @article = ArticleRepository
    .published
    .find(params[:id])
    end
    end
    end
    

    View Slide

26. module Web::Controllers::Articles
    class Create
    include Web::Action
    expose :article
    def call(params)
    @article = ArticleRepository
    .published
    .find(params[:id])
    end
    end
    end
    

    View Slide

27. 1
    plain objects with
    minimal interfaces
    

    View Slide

28. <%= form_for @article do |f| %>
    
    <%= f.text_field :title %>
    
    <% end %>
    

    View Slide

29. <%= form_for @article do |f| %>
    
    <%= f.text_field :title %>
    
    <% end %>
    

    View Slide

30. <%= form_for @article do |f| %>
    
    <%= f.text_field :title %>
    
    <% end %>
    

    View Slide

31. <%= form_for @article do |f| %>
    
    <%= f.text_field :title %>
    
    <% end %>
    

    View Slide

32. <%= form_for @article do |f| %>
    
    <%= f.text_field :title %>
    
    <% end %>
    

    View Slide

33. <%=
    form_for :article,
    routes.articles_path do
    div do
    text_field :title
    end
    end
    %>
    

    View Slide

34. module Web::Views::Articles
    class Index
    include Web::View
    include Lotus::Helpers
    def comments_count
    format_number(
    articles.comments_count
    )
    end
    end
    end
    

    View Slide

35. 2
    Explicit and intention
    revealing interfaces
    

    View Slide

36. 3
    Avoid monkey
    patching
    

    View Slide

37. class Article < ActiveRecord::Base
    validates :title,
    presence: true
    end
    

    View Slide

38. class Article < ActiveRecord::Base
    validates :title,
    presence: true,
    unless: :draft?
    end
    

    View Slide

39. class Article < ActiveRecord::Base
    validates :title,
    presence: true,
    unless: :draft?
    validates :slug,
    presence: true,
    on: :update
    end
    

    View Slide

40. class Article < ActiveRecord::Base
    validates :title,
    presence: true,
    unless: :draft?
    validates :slug,
    presence: true,
    on: :update
    before_validate :set_slug
    end
    

    View Slide

41. class Article < ActiveRecord::Base
    validates :title,
    presence: true,
    unless: :draft?
    validates :slug,
    presence: true,
    on: :update
    before_validate :set_slug,
    on: :create
    end
    

    View Slide

42. “There are nineteen callbacks
    in total, which give you
    immense power to react and
    prepare for each state in the
    Active Record life cycle.”
    

    View Slide

43. class Article
    attr_accessor :title, :slug
    def initialize(title:, slug:)
    @title = title
    @slug = slug
    end
    end
    

    View Slide

44. defmodule Article do
    schema "articles" do
    field :title
    end
    @required_fields ~w(title)
    def changeset(article, params \\ :empty) do
    article
    |> cast(params, @required_fields, [])
    |> validate_length(:title, max: 255)
    end
    end
    

    View Slide

45. 4
    Favour many small objects
    over few large ones
    

    View Slide

46. class UserRepository < ROM::Repository::Base
    relations :users, :tasks
    def with_tasks(id)
    users.by_id(id)
    .combine_children(many: tasks)
    end
    end
    user_repo.with_tasks.to_a
    # [#tasks=[#title="Jane Task">]>]
    

    View Slide

47. class PostMapper < ROM::Mapper
    attribute :title,
    from: 'post_title'
    wrap :author do
    attribute :name,
    from: 'post_author'
    attribute :email,
    from: 'post_author_email'
    end
    end
    

    View Slide

48. 5
    Don’t manage state,
    transform data
    

    View Slide

49. 6
    Embrace, but isolate
    your database
    

    View Slide

50. # Gemfile
    gem "jquery-rails"
    gem "sprockets"
    # app/assets/javascripts/application.js
    #= require jquery
    #= require jquery_ujs
    

    View Slide

51. config :example_phoenix_app,
    ExamplePhoenixApp.Endpoint,
    http: [port: 4000],
    debug_errors: true,
    code_reloader: true,
    watchers: [node: [
    "node_modules/brunch/bin/brunch",
    "watch",
    "--stdin"
    ]]
    

    View Slide

52. 7
    Do one thing,
    and do it well
    

    View Slide

53. 8
    When you find yourself
    in a hole, stop digging
    

    View Slide

54. class Article < ActiveRecord::Base
    has_many :comments
    end
    article = Article.new
    article.comments
    # => <#ActiveRecord::Relation []>
    

    View Slide

55. class Article < ActiveRecord::Base
    has_many :comments
    end
    article = Article.new
    article.comments.build
    

    View Slide

56. “Ecto does not provide
    functions like post.comments
    << comment that allows
    mixing persisted data with
    non-persisted data.”
    

    View Slide

57. 9
    Be transparent
    

    View Slide

58. # app/views/articles/_article.html.erb
    
    <%= article.title %>
    
    

    View Slide

59. # app/views/articles/_article.html.erb
    
    <%= article.title %>
    <%= render article.comments %>
    
    

    View Slide

60. query = from a in Article, limit: 1
    article = Repo.one(query)
    article.comments
    # => Ecto.Association.NotLoaded
    

    View Slide

61. query = from a in Article,
    preload: [:comments],
    limit: 1
    article = Repo.one(query)
    article.comments
    # => []
    

    View Slide

62. “Lazy loading is often a
    source of confusion and
    performance issues and
    Ecto pushes developers to
    do the proper thing.”
    

    View Slide

63. 10
    Nudge developers into
    the right direction
    

    View Slide

64. View Slide

65. View Slide

66. class ArticlesController
    def index
    @articles = Article.recent
    respond_to do |format|
    format.html
    format.xml do
    @articles = @articles.limit(10)
    end
    end
    end
    end
    

    View Slide

67. class ArticlesController
    def show
    @article = Article.find(params[:id])
    fresh_when @article, public: true
    end
    end
    

    View Slide

68. <%= form_for @article do |f| %>
    <%= f.input :title %>
    <%= f.input :body %>
    <% end %>
    

    View Slide

69. protect_from_forgery with: :exception
    config.filter_parameters << :password
    

    View Slide

70. Forms, Security
    HTTP, Conventions
    

    View Slide

71. Rapid prototyping
    

    View Slide

72. Good design nudges us
    in the right direction
    

    View Slide

73. Convention over
    configuration
    

    View Slide

74. Simplicity over
    convenience
    

    View Slide

75. Arjan van der Gaag
    @avdgaag
    arjanvandergaag.nl
    brightin.nl
    

    View Slide