Abusing The Router (For Hexagonal Fun) - RoRoSyd December 12

A short overview of the Hexagonal Architecture style with some fun usages of the router to help us out.

Transcript

1. ABUSING THE ROUTER (FOR HEXAGONAL FUN) JON ROWE
2. World.new.hello! Hi everybody. I’m Jon.
3. World.new.hello! Hi everybody. I’m Jon. Freelance Rubyist.
4. World.new.hello! Hi everybody. I’m Jon. Freelance Rubyist. Why is the rum gone?
5. ABUSING THE ROUTER (FOR HEXAGONAL FUN) JON ROWE
6. HEXAWAT?
7. HEXAGONAL Hexagonal Architecture
8. HEXAGONAL Hexagonal Architecture Describes the structure of an app
9. HISTORY
10. HISTORY Originally by Alistair Cockburn
11. Application
12. HISTORY Originally by Alistair Cockburn Also called “Ports and Adaptors”
13. HEXAGONAL
14. HEXAGONAL Decouple the application
15. HEXAGONAL Decouple the application Make the business logic the focus
16. HEXAGONAL Decouple the application Make the business logic the focus Provide adaptors for technology
17. HEXAGONAL Decouple the application Make the business logic the focus Provide adaptors for technology Provide adaptors for I/O
18. HEXAGONAL RAILS
19. HEXAGONAL RAILS Describes structure of application
20. HEXAGONAL RAILS Describes structure of application but... Rails is not the application
21. HEXAGONAL RAILS Describes structure of application but... Rails is not the application ... Rails is the HTTP Adaptor
22. HEXAGONAL RAILS Describes structure of application but... Rails is not the application ... Rails is the HTTP Adaptor Describes building apps *with* Rails
23. Application
24. RAILS DB LOGGING CMD LINE Application
25. WHY?
26. WHY? Separate responsibilities
27. WHY? Separate responsibilities Push dependencies inwards
28. WHY? Separate responsibilities Push dependencies inwards Make things more explicit
29. WHY?
30. WHY? Modular code
31. WHY? Modular code Isolated / Testable code
32. WHY? Modular code Isolated / Testable code Cleaner code
33. HOW?
34. HOW? Dependency Injection / Inversion
35. HOW? Dependency Injection / Inversion Pure Ruby service classes
36. HOW? Dependency Injection / Inversion Pure Ruby service classes Response Objects
37. HOW? Dependency Injection / Inversion Pure Ruby service classes Response Objects Define an API
38. BUT WAIT... WASN’T THIS TALK ABOUT THE ROUTER?
39. Pushing Inwards
40. Pushing Inwards Dependency Inversion
41. Pushing Inwards Dependency Inversion Push things down into the app
42. Pushing Inwards Dependency Inversion Push things down into the app Take decisions early
43. Pushing Inwards Dependency Inversion Push things down into the app Take decisions early Tell don’t ask
44. Rails
45. Rails The router is top of the Rails stack
46. Rails The router is top of the Rails stack Push inwards from there
47. Rails The router is top of the Rails stack Push inwards from there Without an addition to the framework?
48. Rails The router is top of the Rails stack Push inwards from there Without an addition to the framework?
49. resources :one, controller: :generic, type: One resources :two, controller: :generic, type: Two controller GenericController def show params[:type].find params[:id] end #snip... end Router
50. resources :listing class ListingController before_filter :ensure_admin!, except: :show #snip... end Router
51. namespace :admin resources :listing, except: :show end resources :listing, only: :show Router
52. constraint IsAdmin do resources :listing, except: :show end constraint IsUser do resources :listing, only: :show end Router
53. Constraints class IsAdmin def self.matches? request request.env[‘warden.env’].user!.is_admin? end end class IsUser def self.matches? request request.env[‘warden.env’].user! end end
54. Constraints constraint AllowedAccess.new(:beta) do resource :shiney_thing end class AllowedAccess < Struct.new(:feature) attr_reader :feature def matches? request unless Features.new(user).allow? feature throw :warden, Warden::Redirect... end end end
55. Summary
56. Summary Push things inwards
57. Summary Push things inwards Isolate your business logic
58. Summary Push things inwards Isolate your business logic Bend Rails to your application
59. Summary Push things inwards Isolate your business logic Bend Rails to your application Have fun!
60. THANKS @jonrowe (Twitter, GitHub, etc) http://jonrowe.co.uk P.S. I’m available...