2024 - COSCUP - Clean Architecture in Rails

Transcript

1. Clean Architecture in Rails The way to large Rails application
2. 蒼時弦也 Software Developer https://blog.aotoki.me @elct9620
5. Single Responsibility Dependency Injection Clean Architecture Clean Architecture in Rails
6. Single Responsibility Dependency Injection Clean Architecture Clean Architecture in Rails
7. Single Responsibility Dependency Injection Clean Architecture Clean Architecture in Rails
8. Single Responsibility Dependency Injection Clean Architecture Clean Architecture in Rails
9. Single Responsibility
10. 負責一件事情（ ） 關注點分離
11. 可能同時有多個功能（計算 + 讀寫）
12. 對系統切分的粒度
13. class def end end ; Desk work
14. class def end def = += end def = end def end end ; (amount ) @height amount (amount ); (slot); Desk work up down memory # Standing Desk # ... 1 1
15. class def = end end
 class def = new
 end def = end
 end (amount ); @motor . (amount ) @motor.forward(amount) Motor
 forward Desk
 initialize up 1 Motor 1 # ... # ... # ...
16. class def = end end
 (amount ); Motor
 forward 1 # ... class Desk
 def initialize @motor = Motor.new
 end # ... def up(amount=1) @motor.forward(amount) end
 # ... end
17. class < def end private def end def end end ; ; ; CheckoutController ApplicationController create calculate_discount calculate_amount # ...
18. class end class end class < def end end ; DiscountService CheckoutService CheckoutController ApplicationController create # ...
19. class end class end DiscountService CheckoutService class CheckoutController < ApplicationController def create; end # ... end
20. Dependency Injection
21. 由呼叫者提供依賴的物件或函式
22. 實踐 ，達到低耦合的程式 關注點分離
23. 在 Ruby 可以用 Duck Typing 方式實踐
24. class def = end end
 class def = new
 end def = end
 end (amount ); @motor . (amount ) @motor.forward(amount) Motor
 forward Desk
 initialize up 1 Motor 1 # ... # ... # ...
25. class def = end def = end
 end (motor) @motor motor
 (amount ) @motor.forward(amount) Desk
 initialize up # ... # ... 1
26. class end class end = new new = new new ; ; @standing_desk . ( . ) @electrical_standing_desk . ( . ) Motor ElectricMotor # 手動 # 電動 Desk Motor Desk ElectricMotor
27. class end class end class < def = new end end @discount . @discount.call(@order)
 DiscountService AnniversaryDiscountService CheckoutController ApplicationController create DiscountService # ... # ...
28. class DiscountService end class AnniversaryDiscountService end class CheckoutController < ApplicationController def create @discount.call(@order)
 # ... end # ... end @discount . = new AnniversaryDiscountService
29. class < def = end def = case when then new else new end end end @discount discount_service @discount.call(@order)
 @discount_service .current_store_event . . CheckoutController ApplicationController create discount_service # ... # ... Settings :anniversary AnniversaryDiscountService DiscountService
30. Clean Architecture
31. Architecture Framework Design 粗略 詳細 架構是從宏觀的角度觀察，設計則是從微觀的角度
32. 理想狀況 https://www.pinterest.com/pin/205687907955149475/
33. 現實狀況 https://knowyourmeme.com/photos/1624064-unfinished-horse-drawing-flaming-horse-rating
34. 區分出高階（抽象）跟低階（具體）元件
35. # Which is highest?

 # ... # ... class def end end
 class def end end class < def = end end (amount, ); (order); @discount discount_service
 Order add_discount GeneralDiscountService call CheckoutController ApplicationController create reason:
36. Controller Checkout Service Discount Entity Order 低階 高階 被越多物件引用的物件通常越高階（抽象）
37. https://blog.cleancoder.com/uncle-bob/2012/08/13/the-clean-architecture.html
38. 越低階的物件越容易跟其他東西耦合
39. class def end end class < def = end end class < def end end (text); res commander.call(...) client.reply(res) TextCommander call LineBotController ApplicationController callback MessengerBotController ApplicationController callback # ... # ...
40. Clean Architecture 嘗試找出不同元件之間的邊界
41. 釐清邊界後，如何設計依賴、劃分模組就會有更清晰的方向
42. Clean Architecture in Rails
43. https://blog.cleancoder.com/uncle-bob/2012/08/13/the-clean-architecture.html
44. Rails 的 Model、View、Controller 分別屬於哪一層？
45. Controller Presenter Model Entity View Presenter Business Logic
46. https://blog.cleancoder.com/uncle-bob/2012/08/13/the-clean-architecture.html Frameworks
47. Model 適合當作 Business Logic 分類成 UseCase、Entity 嗎？
48. Controller Controller Model Gateway View Presenter Rails 的 MVC 更可能是同層級的物件
49. Framework Adapter + Business Logic MVC 框架的設計很容易把框架跟商業邏輯耦合在一起
50. Service Object、Value Object 的出現是嘗試提煉商業邏輯
51. Controller Controller Service UseCase View Presenter Business Logic
52. 我們將 Model 視為 Service 的依賴，注入給 Service 使用
53. 然而 Entity 不等於 Model，因為 ActiveRecord 跟底層細節耦合
54. Controller Model View UseCase Entity
55. class < def case in in end end end resolve( ).call(connect_params) => result render result.value, => result render result.failure, ConnectController ApplicationController create 'notify.connect' Success json: status: :created Failure json: status: :unprocessable_entity # ...
56. module class < include private def end def ** = new end end end [ ] step try , :: :: (input) ( , , ) notify :: :: . ( token, type) notifies.save(notify) Notify Connect BaseOperation validate create Deps notifies: :validate :create catch: Notify Errors NotifyAlreadyExists token: type: Notify Entities Notify token: type: 'notify_repository' # ...
57. module module class attr_reader def = = end end end end , ( , ) @token token @type type Notify Entities Notify initialize :token :type token: type: # ...
58. # ActiveRecord model # API client class def = new end end class def end end (entity) notify . notify.assign_attributes(entity.to_h) notify.save! (entity) .upsert(entity.to_h) NotifyRepository save NotifyRepository save NotifyConnection NotifierAPI
59. 基於這樣的調整，除了擴充更容易外，我們也不再綁定框架
60. 以往難以判斷如何拆分物件、將商業邏輯提煉的線索更加清晰
61. 這是 Clean Architecture 應用的一小部分，還有許多面向可以發掘
62. Question & Answer https://bit.ly/3YnmmQJ