You got DDD wrong

Transcript

1. Никита Соболев github.com/sobolevn
2. Вы неправильно поняли DDD
3. Domain Driven Design
4. Focus on the core domain; explore models in a creative collaboration of domain practitioners and software practitioners; and speak a ubiquitous language within an explicitly bounded context — Eric Evans youtube.com/watch?v=R2IAgnpkBck
5. – Сергей, сделай мне отчет по транзакциям
7. Как такая проблема вообще возникла?
8. 1968 • Программистов нет • Код пишут специалисты из предметной области • Каждый отвечает за свой участок youtube.com/watch?v=XH_awPS6hK4
10. ⚙
11. Инструмент технического общения Тайный!
12. Through domain models, software developers are able to express rich functionality and translate it into a software implementation that truly serves the needs of its users — Eric Evans
13. defmodule Projects.Entities.Project do schema "projects" do field :url, :string many_to_many :participants, User, join_through: UserProject, on_replace: :delete end end Project
14. - Let project's participants copy URL
15. - Let project's participants copy URL field :url, :string
16. - Let project's participants copy URL field :url, :string many_to_many :participants, User
17. - Let project's participants copy URL Projects.Entities.Project field :url, :string many_to_many :participants, User
18. defmodule Kira.Usecases.AssignUserToTask do @moduledoc """ We need to assign free `User`s to the most important tasks. We mean `Issue` and `Merge Request` by tasks. Different tasks have different priorities. """ operation(Kira.Projects.Services.FindTaskToAssign) operation(Kira.Accounts.Queries.FindFreeDeveloper) operation(Kira.Accounts.Commands.AssignDeveloper) end Появляются сложные концепции
19. defmodule Kira.Usecases.AssignUserToTask do @moduledoc """ We need to assign free `User`s to the most important tasks. We mean `Issue` and `Merge Request` by tasks. Different tasks have different priorities. """ operation(Kira.Projects.Services.FindTaskToAssign) operation(Kira.Accounts.Queries.FindFreeDeveloper) operation(Kira.Accounts.Commands.AssignDeveloper) end Варианты использования
20. defmodule Kira.Usecases.AssignUserToTask do @moduledoc """ We need to assign free `User`s to the most important tasks. We mean `Issue` and `Merge Request` by tasks. Different tasks have different priorities. """ operation(Kira.Projects.Services.FindTaskToAssign) operation(Kira.Accounts.Queries.FindFreeDeveloper) operation(Kira.Accounts.Commands.AssignDeveloper) end Контексты
21. defmodule Kira.Usecases.AssignUserToTask do @moduledoc """ We need to assign free `User`s to the most important tasks. We mean `Issue` and `Merge Request` by tasks. Different tasks have different priorities. """ operation(Kira.Projects.Services.FindTaskToAssign) operation(Kira.Accounts.Queries.FindFreeDeveloper) operation(Kira.Accounts.Commands.AssignDeveloper) end Сервисы
22. defmodule Kira.Usecases.AssignUserToTask do @moduledoc """ We need to assign free `User`s to the most important tasks. We mean `Issue` and `Merge Request` by tasks. Different tasks have different priorities. """ operation(Kira.Projects.Services.FindTaskToAssign) operation(Kira.Accounts.Queries.FindFreeDeveloper) operation(Kira.Accounts.Commands.AssignDeveloper) end Запросы
23. defmodule Kira.Usecases.AssignUserToTask do @moduledoc """ We need to assign free `User`s to the most important tasks. We mean `Issue` and `Merge Request` by tasks. Different tasks have different priorities. """ operation(Kira.Projects.Services.FindTaskToAssign) operation(Kira.Accounts.Queries.FindFreeDeveloper) operation(Kira.Accounts.Commands.AssignDeveloper) end Команды
24. Usecase Command Query CQRS Event Sourcing Entity Domain Model Value Object Service Agregate Root Bounded Context Context Agregate
25. Usecase Command Query CQRS Event Sourcing Entity Domain Model Value Object Service Agregate Root Bounded Context Context Agregate
26. Usecase Command Query CQRS Event Sourcing Entity Domain Model Value Object Service Agregate Root Bounded Context Context Agregate
29. github.com/johnnncodes/ ddd-python-django
30. class Ticket(object): __uuid = None def __init__(self, uuid, title, body, customer_id): self.set_uuid(uuid) self.set_title(title) self.set_body(body) self.set_customer_id(customer_id) def set_title(self, title): self.__title = title def get_title(self): return self.__title def set_body(self, body): self.__body = body
31. github.com/commanded/ commanded
33. Как так получилось?
37. Как все те умные слова относятся к вашей предметной области?
38. Никак!
39. Инструмент технического общения
40. Архитектурные паттерны Предметная область
41. Архитектурные паттерны Предметная область
42. Например, микросервисы youtube.com/watch? v=yPvef9R3k-M
43. "DDD Framework"
45. Что важно? •Быстрая обратная связь •Общая терминология •Понятные требования
46. – Никита, мне нужен инструмент для автоматизации работы программистов
47. Термины и связи
48. sphinx-doc.org
49. class AwesomeRule(object): """Implementation of :term:`rule` ..."""
50. Сделал – получил обратную связь!
51. Показал – обновил
52. BDD
53. Еще один неправильно понятный инструмент для общения
54. Feature: Tracking issues progress As an architect I want to have information about Gitlab issues So that I can overview and track the issues' progress Scenario: new valid issue webhook is received Given issue webhook is valid And issue webhook is authenticated When it is received Then a new issue is created Scenario: new invalid issue webhook is received Given issue webhook is not valid When it is received Then no issue is created
56. pypi.org/project/pytest-bdd
57. sobolevn.me/2019/02/ engineering-guide-to- user-stories
58. Мы понимаем что делать
59. Заказчик понимаем, что мы делаем
60. Сделал – получил обратную связь!
62. Мы можем быть уверены: работает, то, так
63. Выводы •DDD позволяет людям понять друг друга •DDD поднимает сознательность, заставляет думать про бизнес •DDD позволяет быстрее решать задачи •DDD заставляет думать про архитектуру
64. Материалы •DDD EU •twitter.com/DDD_Borat •fsharpforfunandprofit.com/ddd/ •fideloper.com/hexagonal-architecture •martinfowler.com/eaaCatalog/index.html •github.com/heynickc/awesome-ddd •github.com/dry-python
65. Вопросы? github.com/sobolevn sobolevn.me