The Good Architecture

Transcript

1. The Good Architecture
2. Krzysztof Wawer Github: wafcio Twitter: @wafcio
3. 1. Principles 2. Architectures
4. Principles
5. Principles • DRY
6. Principles • DRY • KISS
7. Principles • DRY • KISS • SOLID
8. Principles • DRY • KISS • SOLID • YAGNI
9. DRY “Don’t Repeat Yourself” Andrew Hunt and David Thomas, October 1999, The Pragmatic Bookshelf
10. DRY extras extras_allowed?(shop, invoice, order) … … … … … … … … … …
11. KISS “Keep it simple, stupid” “Keep it stupid simple” U.S. Navy in 1960, aircraft engineer Kelly Johnson
12. KISS
13. < = > LESS IS MORE
14. SOLID • SRP (Single Responsible Principle) • OCP (Open/Closed Principle) • LSP (Liskov Substitution Principle) • ISP (Interface Segregation Principle) • DIP (Dependency Inversion Principle) Robert C. Martin (Uncle Bob)
15. SRP Single Responsible Principle • 2002 • A class should have one, and only one, reason to change http://rubyblog.pro/2017/05/solid-single-responsibility-principle-by-example
16. SRP Single Responsible Principle
17. Contexts
18. OCP Open/Closed Principle • 1996 • You should be able to extend a classes behavior, without modifying it http://rubyblog.pro/2017/05/solid-open-closed-principle-by-example
19. LSP Liskov Substitution Principle • 1987 • Barbara Liskov • Let Φ(x) be a property provable about objects x of type T. Then Φ(y) should be true for objects y of type S where S is a subtype of T. http://rubyblog.pro/2017/06/solid-liskov-substitution-principle
20. LSP Liskov Substitution Principle • objects in a program should be replaceable with instances of their subtypes without altering the correctness of that program http://rubyblog.pro/2017/06/solid-liskov-substitution-principle
21. LSP anti-pattern
22. ISP Interface Segregation Principle • 1996 • Clients should not be forced to depend upon interfaces that they don't use. http://rubyblog.pro/2017/07/solid-interface-segregation-principle
23. DIP Dependency Inversion Principle • 1996 • High-level modules should not depend on low-level modules. Both should depend on abstractions • Abstractions should not depend on details. Details should depend on abstractions. http://rubyblog.pro/2017/07/solid-dependency-inversion-principle
24. SOLID Robert C. Martin (Uncle Bob)
25. YAGNI You aren't gonna need it • principle of extreme programming (XP) • XP co-founder Ron Jeffries has written: "Always implement things when you actually need them, never when you just foresee that you need them."
26. Architectures
27. Software Architecture Chronicles 2000s • 2003 - Domain Driven Design • 2005 - Ports & Adapters Architecture aka Hexagonal Architecture • ~2006 - CQRS & ES (Event Sourcing) • 2008 - Onion Architecture • 2012 - Clean Architecture
28. Domain Driven Design
29. Domain Driven Design
30. Software Architecture Chronicles 2000s • 2003 - Domain Driven Design • 2005 - Ports & Adapters Architecture aka Hexagonal Architecture • ~2006 - CQRS & ES (Event Sourcing) • 2008 - Onion Architecture • 2012 - Clean Architecture
31. Hexagonal Architecture
32. Hexagonal Architecture
33. Hexagonal Architecture
34. Hexagonal Architecture
35. Hexagonal Architecture
36. Hexagonal Architecture
37. Hexagonal Architecture
38. Hexagonal Architecture
39. Hexagonal Architecture
40. Hexagonal Architecture
41. Software Architecture Chronicles 2000s • 2003 - Domain Driven Design • 2005 - Ports & Adapters Architecture aka Hexagonal Architecture • ~2006 - CQRS & ES (Event Sourcing) • 2008 - Onion Architecture • 2012 - Clean Architecture
42. CQS Command Query Separation • devised by Bertrand Meyer during his work on the Eiffel programming language • Queries: Return a result and do not change the observable state of the system (are free of side effects) • Commands: Change the state of a system but do not return a value
43. Command Query Responsible Segregation 2006 Greg Young describes CQRS
44. Command Query Responsible Segregation
45. Command Query Responsible Segregation
46. Software Architecture Chronicles 2000s • 2002 - SRP (SOLID) • 2003 - Domain Driven Design • 2005 - Ports & Adapters Architecture aka Hexagonal Architecture • ~2006 - CQRS & ES (Event Sourcing) • 2008 - Onion Architecture • 2012 - Clean Architecture
47. Event-Driven Architecture • Event Notification (Event Bus) • Event Sourcing (Event Store)
48. Event-Driven Architecture
49. Event Sourcing
50. Software Architecture Chronicles 2000s • 2002 - SRP (SOLID) • 2003 - Domain Driven Design • 2005 - Ports & Adapters Architecture aka Hexagonal Architecture • ~2006 - CQRS & ES (Event Sourcing) • 2008 - Onion Architecture • 2012 - Clean Architecture
51. Onion Architecture https://herbertograca.com/2017/09/21/onion-architecture/
52. Software Architecture Chronicles 2000s • 2002 - SRP (SOLID) • 2003 - Domain Driven Design • 2005 - Ports & Adapters Architecture aka Hexagonal Architecture • ~2006 - CQRS & ES (Event Sourcing) • 2008 - Onion Architecture • 2012 - Clean Architecture
53. Clean Architecture https://blog.cleancoder.com/uncle-bob/2012/08/13/the-clean-architecture.html
54. No architecture
55. @herbertograca • https://herbertograca.com • The Software Architecture Chronicles • The Containerization Chronicles • Domain Driven Design • Lean Architecture • Patterns of Enterprise Application Architecture • Patterns Principles and Practices of Domain-Driven Design • The mythical man-month
56. Q & A