Hexagonal architecture: how, why and when
- 3. Hexagonal Architecture: how, why and when - 11/2019 3 About meAbout me Carlos Gándara software developer at @xoubaman
- 4. Hexagonal Architecture: how, why and when - 11/2019 4 Why?
- 5. Hexagonal Architecture: how, why and when - 11/2019 5 A journey through architectural patterns
- 6. Hexagonal Architecture: how, why and when - 11/2019 6
- 7. Hexagonal Architecture: how, why and when - 11/2019 7 Spaghetti
- 8. Hexagonal Architecture: how, why and when - 11/2019 8 Spaghetti architecture ✅ Fun to revisit after some years... ✅ Valid for small proof of concept scripts with a 10 minutes life expectancy ...although that means you have it on production
- 9. Hexagonal Architecture: how, why and when - 11/2019 9
- 10. Hexagonal Architecture: how, why and when - 11/2019 10 MVC
- 11. Hexagonal Architecture: how, why and when - 11/2019 11 HTTP language Database language Business rules Data centric MVC architecture
- 12. Hexagonal Architecture: how, why and when - 11/2019 12 Ctrl+C Ctrl+V We want to add products from the console MVC architecture
- 13. Hexagonal Architecture: how, why and when - 11/2019 13 I just realized products have also a max price WET code (makes you sweat) MVC architecture
- 14. Hexagonal Architecture: how, why and when - 11/2019 14 Controllers go fat MVC architecture
- 15. Hexagonal Architecture: how, why and when - 11/2019 15 MVC architecture ❌ No isolation of business logic ✅ Valid for prototyping and purely CRUD applications ❌ Data centric ❌ Hard to test, infrastructure everywhere
- 16. Hexagonal Architecture: how, why and when - 11/2019 16
- 17. Hexagonal Architecture: how, why and when - 11/2019 17 Layered architecture
- 18. Hexagonal Architecture: how, why and when - 11/2019 18 Layered architecture HTTP & CLI Same application service Diagram from book DDD in PHP
- 19. Hexagonal Architecture: how, why and when - 11/2019 19 Layered architecture (the wrong way) Now need to read products from this random API And we should notify warehouse guys Database language Outside world Outside world Our thing
- 20. Hexagonal Architecture: how, why and when - 11/2019 20 Layered architecture (the wrong way) Hey, plz generate a RSS feed with products we read from this weird machine And did I mentioned we are migrating to Mongo? Combinatorial explosion Infrastructure coupling
- 21. Hexagonal Architecture: how, why and when - 11/2019 21 Layered architecture (the wrong way) Hey, plz generate a RSS feed with products we read from this weird machine And did I mentioned we are migrating to Mongo? Combinatorial explosion Infrastructure coupling Aren’t tests taking too much time? Testability
- 22. Hexagonal Architecture: how, why and when - 11/2019 22 Layered architecture ❌ Data persistence is in the core* ✅ Separation of concerns ✅ Application layer encapsulating use cases ❌ Potential infrastructure leaks in other layers* ✅ You can build good stuff ❌ Lasagna antipattern * if you do it wrong
- 23. Hexagonal Architecture: how, why and when - 11/2019 23
- 24. Hexagonal Architecture: how, why and when - 11/2019 24 Hexagonal architecture
- 25. Hexagonal Architecture: how, why and when - 11/2019 25 Aka Ports and Adapters Coined by Alistair Cockburn in 2005 Hexagonal architecture Check out Alistair in the "Hexagone" in Youtube
- 26. Hexagonal Architecture: how, why and when - 11/2019 26 Allow an application to equally be driven by users, programs, automated test or batch scripts, and to be developed and tested in isolation from its eventual run-time devices and databases. Hexagonal architecture
- 27. Hexagonal Architecture: how, why and when - 11/2019 27 Outside the application A boundary Application Hexagonal architecture
- 28. Hexagonal Architecture: how, why and when - 11/2019 28 Port: ● Outside element communicating with the application ● Defined by an interface* Application Adapter: ● Implementation of a port interface into what application understands *Not a code interface, although sometimes represented by one Ports and adapters
- 29. Hexagonal Architecture: how, why and when - 11/2019 29 Primary ports Drivers Secondary ports Repositories and recipients Ports and adapters
- 30. Hexagonal Architecture: how, why and when - 11/2019 30 Test driver User interface Router + HTTP Controller Ports and adapters CLI Console component REST API External application Other adapter Other adapter
- 31. Hexagonal Architecture: how, why and when - 11/2019 31 Ports and adapters REST API adapter with Symfony: ● Routing component ● HTTP Kernel and Controller ● HTTP component Request
- 32. Hexagonal Architecture: how, why and when - 11/2019 32 Ports and adapters Persistence Queue Feed Interface implementation Interface implementation Interfaces defined by the application
- 33. Hexagonal Architecture: how, why and when - 11/2019 33 Ports and adapters Persistence adapter with Doctrine ORM Application defines the contract in its own language We don’t care about using database or library language in the adapter
- 34. Hexagonal Architecture: how, why and when - 11/2019 34 Ports and adapters Persistence adapter with Doctrine ORM No infrastructure leaks Testability improved!
- 35. Hexagonal Architecture: how, why and when - 11/2019 35 How?
- 36. Hexagonal Architecture: how, why and when - 11/2019 36 Allow an application to equally be driven by users, programs, automated test or batch scripts, and to be developed and tested in isolation from its eventual run-time devices and databases. Hexagonal architecture No mention to layers...
- 37. Hexagonal Architecture: how, why and when - 11/2019 37 Hexagonal architecture You can put whatever you want inside the hexagon
- 38. Hexagonal Architecture: how, why and when - 11/2019 38 Hexagonal + Layered
- 39. Hexagonal Architecture: how, why and when - 11/2019 39 Hexagonal + Layered
- 40. Hexagonal Architecture: how, why and when - 11/2019 40 User Interface and Infrastructure layer: ● UI for primary ports adapters ● Infrastructure for secondary ports implementations Application layer: ● Defines the system use cases ● Orchestrates the domain logic ● Command + Command Handler pattern Domain layer: ● Holds all the business logic and invariants ● Defines the contracts implemented in infrastructure Hexagonal + Layered: a proposal
- 41. Hexagonal Architecture: how, why and when - 11/2019 41 Hexagonal + Layered Domain Application UI Infrastructure
- 42. Hexagonal Architecture: how, why and when - 11/2019 42 Hexagonal + Layered: Domain layer Domain Application UI Infrastructure Don’t leak infrastructure in your domain
- 43. Hexagonal Architecture: how, why and when - 11/2019 43 Hexagonal + Layered: Application layer Domain Application UI Infrastructure More logic than this is suspicious
- 44. Hexagonal Architecture: how, why and when - 11/2019 44 Hexagonal + Layered: Driver port Domain Application UI Infrastructure
- 45. Hexagonal Architecture: how, why and when - 11/2019 45 Hexagonal + Layered: Repository port Domain Application UI Infrastructure Dependency inversion
- 46. Hexagonal Architecture: how, why and when - 11/2019 46 When?
- 47. Hexagonal Architecture: how, why and when - 11/2019 47 When to apply hexagonal architecture? ALWAYS*
- 48. Hexagonal Architecture: how, why and when - 11/2019 48 When to apply hexagonal architecture? Pros ● Testability ● Promotes separation of concerns ● Pushes accidental complexity out of the domain ● Open/Closed ● Handy base for DDD ● Handy base for CQRS and ES Cons ● Indirection ● Amount of boilerplate code
- 49. Hexagonal Architecture: how, why and when - 11/2019 49 When to apply hexagonal architecture? Makes no sense for ● Scripting ● Prototyping ● Tooling ● Frameworks Makes sense for ● Applications relying on external technologies ● CRUD applications ● Anything more complex than that
- 50. Hexagonal Architecture: how, why and when - 11/2019 50 When to apply hexagonal architecture? Take decisions based on the context and needs Keep in mind the reasons and the consequences ALWAYS
- 51. Hexagonal Architecture: how, why and when - 11/2019 51 Questions?
- 52. Hexagonal Architecture: how, why and when - 11/2019 ● Slides of this presentation anytime soon in @xoubaman ● Article: Hexagonal Architecture by Alistair Cockburn ● Article: Hexagonal Architecture by Fideloper ● Article: DDD, Hexagonal, Onion, Clean, CQRS, … How I put it all together by Hebert Graca ● Video: Introducción Arquitectura Hexagonal (Spanish) by CodelyTV ● Video: Hexagonal Architecture - Message-Oriented Software Design by Matthias Noback ● Video: Alistair in the “Hexagone” by DDD FR ● Book: DDD in PHP by Carlos Buenosvinos, Christian Soronellas, and Keyvan Akbary ● Book: Implementing Domain Driven Design by Vaughn Vernon ● Code samples glittered with Carbon 52 Some resources to follow up
- 53. Thank you!