An Introduction of Interator Pattern with Ruby

Transcription

1 An Introduction of Interator Pattern with ConFoo Montreal by Jian Weihang An Introduction of Interator Pattern in Ruby 1

2 Bonjour! An Introduction of Interator Pattern in Ruby 2

3 Jian Weihang An Introduction of Interator Pattern in Ruby 3

4 @tonytonyjan An Introduction of Interator Pattern in Ruby 4

5 Taiwan An Introduction of Interator Pattern in Ruby 5

6 An Introduction of Interator Pattern in Ruby 6

7 An Introduction of Interator Pattern in Ruby 7

8 An Introduction of Interator Pattern in Ruby 8

9 $ gem install taiwan An Introduction of Interator Pattern in Ruby 9

10 Tech Leader An Introduction of Interator Pattern in Ruby 10

11 Ruby Developer since 2010 An Introduction of Interator Pattern in Ruby 11

12 Maintainer of exif and jaro_winkler An Introduction of Interator Pattern in Ruby 12

13 Published a book in 2015 An Introduction of Interator Pattern in Ruby 13

14 An Introduction of Interator Pattern in Ruby An Introduction of Interator Pattern in Ruby 14

15 Outline An Introduction of Interator Pattern in Ruby 15

16 An Introduction of Interator Pattern in Ruby 16

17 ! An Introduction of Interator Pattern in Ruby 17

18 An Introduction of Interator Pattern in Ruby 18

19 How to Help Controllers Lose Weight? An Introduction of Interator Pattern in Ruby 19

20 The Controller Is a Translator An Introduction of Interator Pattern in Ruby 20

21 Good Practice class PostsController < ApplicationController def = Post.create(post_params) rescue rer :new An Introduction of Interator Pattern in Ruby 21

22 Bad Practice class PostsController < ApplicationController def = rescue rer :new An Introduction of Interator Pattern in Ruby 22

23 ! An Introduction of Interator Pattern in Ruby 23

24 Fat Models and Skinny Controllers An Introduction of Interator Pattern in Ruby 24

25 Single Responsibility Principle An Introduction of Interator Pattern in Ruby 25

26 # Rails class Post < ActiveRecord::Base Post.new.public_methods.size # => 404 An Introduction of Interator Pattern in Ruby 26

27 class AlmightyGod < ActiveRecord::Base # hundreds of methods An Introduction of Interator Pattern in Ruby 27

28 class Cart < ApplicationModel def add_product(product) vs. class Product < ApplicationModel def add_to_cart(cart) An Introduction of Interator Pattern in Ruby 28

29 class Course def add_student(student) vs. class Student def join_course(course) An Introduction of Interator Pattern in Ruby 29

30 ! An Introduction of Interator Pattern in Ruby 30

31 Model is neither a class nor object. An Introduction of Interator Pattern in Ruby 31

32 Model is a layer. An Introduction of Interator Pattern in Ruby 32

33 Separation of Concerns Presentation Layer views controllers Model Layer models An Introduction of Interator Pattern in Ruby 33

34 Model Layer Domain Objects Storage Abstractions Services An Introduction of Interator Pattern in Ruby 34

35 Model Layer Domain Objects Storage Abstractions Services An Introduction of Interator Pattern in Ruby 35

36 Model Layer Domain Objects Storage Abstractions Services An Introduction of Interator Pattern in Ruby 36

37 Model Layer Domain Objects Storage Abstractions Services An Introduction of Interator Pattern in Ruby 37

38 Model Layer ActiveRecord::Base Domain Objects Storage Abstractions Services??? An Introduction of Interator Pattern in Ruby 38

39 What about the Implementation An Introduction of Interator Pattern in Ruby 39

40 Service Object a.k.a. Interactor Use Case An Introduction of Interator Pattern in Ruby 40

41 Clean Architecture An Introduction of Interator Pattern in Ruby 41

42 Minimal Implementation # app/{services interactors use_cases} class AddToCart attr_reader :errors def = cart, = [] def perform def An Introduction of Interator Pattern in Ruby 42

43 Usage class CartController < ApplicationController def add_to_cart product = Product.find(params[:product_id]) add_to_cart = AddToCart.new(current_cart, product) add_to_cart.perform if add_to_cart.successs? #... else #... An Introduction of Interator Pattern in Ruby 43

44 Advantages Skinny Controller Easier to Trace Code Easier to Write Test An Introduction of Interator Pattern in Ruby 44

45 Advantages Skinny Controller Easier to Trace Code Easier to Write Test An Introduction of Interator Pattern in Ruby 45

46 Advantages Skinny Controller Easier to Trace Code Easier to Write Test An Introduction of Interator Pattern in Ruby 46

47 Advantages Skinny Controller Easier to Trace Code Easier to Write Test An Introduction of Interator Pattern in Ruby 47

48 class AddToCart def = cart, product def An Introduction of Interator Pattern in Ruby 48

49 gem 'rspec-mocks' describe AddToCart it 'works' do line_items = double('line_items') cart = double('cart', line_items: line_items) product = double('product') expect(line_items).to receive(:push).once { product } # expect cart.line_items.push(product) add_to_cart = AddToCart.new(cart, product) add_to_cart.perform An Introduction of Interator Pattern in Ruby 49

50 Abstraction class Interactor attr_reader :errors def self.perform(*args) new(*args).tap { interactor interactor.perform } def perform raise NotImplementedError def An Introduction of Interator Pattern in Ruby 50

51 Usage class AddToCart < Interactor def initialize(cart, = = product def perform # logic here. An Introduction of Interator Pattern in Ruby 51

52 Usage class CartController < ApplicationController def add_to_cart product = Product.find(params[:product_id]) add_to_cart = AddToCart.perform(current_cart, product) if add_to_cart.successs? #... else #... An Introduction of Interator Pattern in Ruby 52

53 ! An Introduction of Interator Pattern in Ruby 53

54 Third-party Gems An Introduction of Interator Pattern in Ruby 54

55 gem "mutations" class UserSignup < Mutations::Command required do string : , matches: _REGEX string :name optional do boolean :newsletter_subscribe def execute # logic UserSignup.run(params[:user]) An Introduction of Interator Pattern in Ruby 55

56 gem "interactor" class AuthenticateUser include Interactor def call if user = User.authenticate(context. , context.password) context.user = user context.token = user.secret_token else context.fail!(message: "authenticate_user.failure") AuthenticateUser.call(params) An Introduction of Interator Pattern in Ruby 56

57 FYI name stars forks issues closed mutation 1, % interactor 1, % An Introduction of Interator Pattern in Ruby 57

58 gem "interactor2" class AddToCart < Interactor2 attr_reader :line_item, :cart # should be any attribute you want to expose def initialize(product, = = cart.line_items.new(product: product) def perform fail! 'oops' An Introduction of Interator Pattern in Ruby 58

59 gem "interactor2" class AddToCart < Interactor2 include ActiveModel::Validations attr_reader :line_item, :cart # should be any attribute you want to expose validates :product, :cart, presence: true def initialize(product, = = cart.line_items.new(product: product) def perform fail! 'oops' An Introduction of Interator Pattern in Ruby 59

60 An Introduction of Interator Pattern in Ruby 60

61 Conclusion Consistent Interface Self-explaining Context Encapsulation Decoupling your domain from your framework An Introduction of Interator Pattern in Ruby 61

62 Conclusion Consistent Interface Self-explaining Context Encapsulation Decoupling your domain from your framework An Introduction of Interator Pattern in Ruby 62

63 Conclusion Consistent Interface Self-explaining Context Encapsulation Decoupling your domain from your framework An Introduction of Interator Pattern in Ruby 63

64 Conclusion Consistent Interface Self-explaining Context Encapsulation Decoupling your domain from your framework An Introduction of Interator Pattern in Ruby 64

65 Conclusion Consistent Interface Self-explaining Context Encapsulation Decoupling your domain from your framework An Introduction of Interator Pattern in Ruby 65

66 Thanks for Your An Introduction of Interator Pattern in Ruby 66

67 References An Introduction of Interator Pattern in Ruby 67

68 Q&A An Introduction of Interator Pattern in Ruby 68

69 Entity-Boundary-Interactor An Introduction of Interator Pattern in Ruby 69