Palestra apresentada no TDC Florianópolis 2016

1. CHOOSING THE ARCHITECTURE
FROM MV(X) TO VIP(ER)
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2. ABOUT US
Giovane Berny Possebon
Mobile Developer
giovane.possebon@ilegra.com
Lucas Dutra Fonseca
Mobile Developer
lucas.fonseca@ilegra.com

3. WHY CARE
ABOUT IT?
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4. "BECAUSE IF YOU DON’T, ONE DAY, DEBUGGING A
HUGE CLASS WITH DOZENS DIFFERENT THINGS,
YOU’LL FIND YOURSELF BEING UNABLE TO FIND
AND FIX ANY BUGS IN YOUR CLASS."
Someone who’s right
WHY CARE ABOUT IT? 4

5. WHY CARE ABOUT IT?
REASONS
▸ This class is the UIViewController subclass.
▸ Your data is stored directly in the UIViewController
▸ Your UIViews do almost nothing
▸ The Model is a dumb data structure
▸ Your Unit Tests cover nothing
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6. WHY CARE ABOUT IT?
SO WHAT A GOOD ARCHITECTURE SHOULD HAVE?
▸ Balanced distribution of responsibilities among entities
with strict roles.
▸ Testability usually comes from the first feature.
▸ Ease of use and a low maintenance cost.
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7. THEN SHOW ME
THESE ARCHITECTURES!
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8. THEN SHOW ME THESE ARCHITECTURES!
RENOWNED ARCHITECTURES
▸ MVC
▸ MVP
▸ MVVM
▸ VIPER
▸ VIP
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9. MVC
MODEL-VIEW-
CONTROLLER
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10. MVC - MODEL-VIEW-CONTROLLER
HOW IT SHOULD BE
VIEW
CONTROLLER
MODEL
Updates
NotifiesSend actions
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11. MVC - MODEL-VIEW-CONTROLLER
HOW IT REALLY IS
VIEW CONTROLLER MODEL
Owns and updates
Notifies
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12. MVC - MODEL-VIEW-CONTROLLER
HOW IT REALLY IS
VIEW CONTROLLER MODEL
Owns and updates
Notifies
MVC
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13. MVC - MODEL-VIEW-CONTROLLER
HOW IT REALLY IS
VIEW CONTROLLER MODEL
Owns and updates
Notifies
Massive View Controller
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14. MVC - MODEL-VIEW-CONTROLLER
CONCLUSION
▸ Distribution of Responsibilities - View and controller tightly
coupled
▸ Testability - Only model is testable
▸ Ease of Use - Low amount of code. Everyone is familiar
with it.
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15. MVP
MODEL-VIEW-PRESENTER
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16. What if I told you, the UIViewController is the View.

17. MVP - MODEL-VIEW-PRESENTER
MVC IN THE RIGHT WAY
PASSIVE VIEW
PRESENTER
MODELUpdates
Owns and updatesOwns and send actions
Notifies
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18. MVP - MODEL-VIEW-PRESENTER
MVC IN THE RIGHT WAY
PASSIVE VIEW
PRESENTER
MODELUpdates
Owns and updatesOwns and send actions
Notifies
UIViewController
UIKit independent mediator
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19. MVP - MODEL-VIEW-PRESENTER
CONCLUSION
▸ Distribution of Responsibilities - Most of responsibilities divided
between the Presenter and the Model, with the pretty dumb View
▸ Testability - Good, we can test most of the business logic due to
the dumb View
▸ Ease of Use - Substantial amount of code, although idea is very
clear
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20. MVVM
MODEL-VIEW-VIEWMODEL
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21. MVVM - MODEL-VIEW-VIEWMODEL
THE GREATEST OF THE MV(X) KIND
VIEW
VIEWMODEL
MODELUpdates
Owns and updatesOwns and send actions
Notifies
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22. MVVM - MODEL-VIEW-VIEWMODEL
CONCLUSION
▸ Distribution of Responsibilities - Similar to MVP, but View
has more responsibilities than the MVP’s
▸ Testability - View Model knows nothing about the View, this
allows us to test it easily. The View might be also tested
▸ Ease of Use - It has almost the same amount of code as the
MVP
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23. VIPER
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24. VIPER
THE LEGO ARCHITECTURE
VIEW
PRESENTER
ENTITY
Updates
Owns and asks for updatesOwns and send actions
Notifies INTERACTOR
ROUTER
Knows about
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25. VIPER
THE LEGO ARCHITECTURE
VIEW
PRESENTER
ENTITY
Updates
Owns and asks for updatesOwns and send actions
Notifies INTERACTOR
ROUTER
Knows about
Manipulates data and
use cases
UIKit independent mediator
Former Model
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26. VIPER
CONCLUSION
▸ Distribution of Responsibilities - VIPER is a champion in
distribution of responsibilities.
▸ Testability - better distribution — better testability
▸ Ease of Use - You have to write huge amount of interface
for classes with very small responsibilities.
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27. VIP
CLEAN SWIFT
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28. VIP
THE CLEAN ARCHITECTURE
VIEW PRESENTER
ENTITY
Updates
Process and deliver dataSend actions INTERACTOR
ROUTER
Knows about
Owns
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29. VIP
THE CLEAN ARCHITECTURE
VIEW PRESENTER
ENTITY
Updates
Process and deliver dataSend actions INTERACTOR
ROUTER
Knows about
Owns
UIKit independent mediator Former Model
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30. VIP
CONCLUSION
▸ Distribution of Responsibilities - VIP is as good as VIPER in
terms of distribution of responsibilities.
▸ Testability - Also comparable to VIPER
▸ Ease of Use - Great amount of classes with very small
responsibilities, but clearer than VIPER
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31. CHOOSING THE ARCHITECTURE
REFERENCES
▸ https://medium.com/ios-os-x-development/ios-
architecture-patterns-ecba4c38de52
▸ http://clean-swift.com/clean-swift-ios-architecture/
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32. CHOOSING THE ARCHITECTURE
CODE REPOSITORY
▸ https://github.com/lfonseca/choosing-the-architecture
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33. THANKS!
Giovane Berny Possebon
Mobile Developer
giovane.possebon@ilegra.com
Lucas Dutra Fonseca
Mobile Developer
lucas.fonseca@ilegra.com

34. EXPERIENCES SO
FAR…
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