Off the Rails: Patterns for fixing fat models, out-of-controllers, and other Rails problems

Transcript

1. Off the Rails
   Patterns for fixing fat models, out-of-controllers, and
   other Rails problems
   

   View Slide

2. What I’m about to tell
   you is wrong.
   

   View Slide

3. YMMV
   

   View Slide

4. MVC
   

   View Slide

5. View
   Controller
   Model
   

   View Slide

6. 3 Tier Architecture
   

   View Slide

7. Business Logic
   Presentation
   Data
   

   View Slide

8. Business Logic
   Presentation
   Data
   

   View Slide

9. Business Logic
   Presentation
   Data
   View
   Controller
   Model
   

   View Slide

10. Business Logic
    Presentation
    Data
    View Controller
    Model
    

    View Slide

11. View Controller
    Model
    Business Logic
    Presentation
    Data
    

    View Slide

12. View Slide

13. View Slide

14. View Slide

15. View Controller
    Model
    

    View Slide

16. Model
    Service
    View Controller
    

    View Slide

17. Business Logic
    Presentation
    Data
    

    View Slide

18. Business Logic
    Presentation
    Data
    

    View Slide

19. Business Logic
    Presentation
    Data
    Service
    

    View Slide

20. View Slide

21. View Slide

22. Controller Rule of Thumb
    A Controller May Contain:
    • Public REST methods
    
    • Private before_action setters
    
    • Private strong params method
    

    View Slide

23. Models
    

    View Slide

24. Business Logic
    Presentation
    Data
    View Controller
    Model
    

    View Slide

25. Business Logic
    Presentation
    Data
    View Controller
    Model
    

    View Slide

26. Business Logic
    Presentation
    Data
    View Controller
    Model
    Repository
    

    View Slide

27. View Slide

28. Business Logic
    Presentation
    Data
    View Controller
    Validator
    Model
    

    View Slide

29. View Slide

30. View Slide

31. View Slide

32. View Slide

33. –Sandi Metz
    “duplication is far cheaper than the wrong
    abstraction”
    

    View Slide

34. YAGNI
    

    View Slide

35. Bonus Tip
    

    View Slide

36. View Slide

37. View Slide

38. Thanks for Listening
    Alexander Clark
    atheclark
    alexander-clark.com
    alexander-clark
    

    View Slide

39. Further reading
    • https://codeclimate.com/blog/7-ways-to-decompose-fat-
    activerecord-models/
    
    • Patterns of Enterprise Application Architecture (Fowler)
    
    • Domain Driven Design (Evans)
    
    • All the Little Things (Metz) https://www.youtube.com/
    watch?v=8bZh5LMaSmE
    
    • Ruby Object Mapper https://rom-rb.org/
    

    View Slide

40. Questions?
    

    View Slide