cosmicpython-book-note

1. Introdution
2. Domain Modeling
3. Repository Pattern
   1. 拓展阅读

Introdution

1. High-level modules should not depend on low-level modules. Both should depend on abstractions.
2. Abstractions should not depend on details. Instead, details should depend on abstractions.

Domain Modeling

• book/chapter_01_domain_model.asciidoc at master · cosmicpython/book

• cosmicpython/code at chapter_01_domain_model_exercise

• 和领域专家沟通了解领域模型

• 领域模型的三个概念：

  • Value Objects
  • Entities
  • domain service

• 领域建模

  • Domain modeling
  • Distinguish entities from value objects
  • Not everything has to be an object
  • This is the time to apply your best OO design principles
  • You’ll also want to think about consistency boundaries and aggregates

• python

  • dataclasses、NewType
  • eq , hash
  • next
  • attrs · PyPI

• 软件工程

  • TDD
  • UML

• 疑问

  • 图里的虚线、实线是什么意思？

Repository Pattern

The Repository pattern is an abstraction over persistent storage

  +-----------------------------+
  |      Application Layer      |
  +-----------------------------+
                 |^
                 ||          /------------------\
                 ||----------|   Domain Model   |
                 ||          |      Objects     |
                 ||          \------------------/
                 V|
  +------------------------------+
  |          Repository          |
  +------------------------------+
                 |
                 V
  +------------------------------+
  |        Database Layer        |
  +------------------------------+

• book/chapter_02_repository.asciidoc at master · cosmicpython/book
• cosmicpython/code at chapter_02_repository

主要内容：如何使用依赖反转将领域模型和数据库解耦

• 传统Layered architecture和Onion architecture的差别
• 如何实现Inverting the Dependency: ORM Depends on Model (以SQLAlchemy为例)
• 如何测试domain -> repo
• 如何测试repo -> database
• 如何创建一个Fake repo进行测试
• 使用Repository Pattern的tradeoff(Pros and cons)

拓展阅读

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