MVI - Yet Another Android Architecture Model

A quick introduction into MVI architecture applied for Android backed by RxKotlin and Mosby MVI 3.0

Demo code: https://github.com/AndroidIasi/Codecamp-2.0/tree/presentation/cluj_181124

Transcript

1. MVI Yet Another Android Architecture Model Andrei Verdes (@averdesh)
3. What is MVI?
4. What is MVI • MVI stands for Model View Intent
5. What is MVI • MVI stands for Model View Intent • Invented by André Medeiros (Staltz) - Cycle.js
6. What is MVI • MVI stands for Model View Intent • Invented by André Medeiros (Staltz) - Cycle.js • State machine
7. What is MVI • MVI stands for Model View Intent • Invented by André Medeiros (Staltz) - Cycle.js • State machine • Immutability
8. What is MVI • MVI stands for Model View Intent • Invented by André Medeiros (Staltz) - Cycle.js • State machine • Immutability • Unidirectional and Circular Data Flows
9. Repository Reducer State Render Interactor Intents Result Intent viewmodel or presenter UI User
11. codecamp app lite (really lite)
12. • Resume screen codecamp app lite (really lite)
13. • Resume screen • Refresh list codecamp app lite (really lite)
14. • Resume screen • Refresh list • Click on the favorite button codecamp app lite (really lite)
15. • Resume screen • Refresh list • Click on the favorite button • Click on an item codecamp app lite (really lite)
16. • Resume screen • Refresh list • Click on the favorite button • Click on an item • Swipe left to <custom action> codecamp app lite (really lite)
17. Repository Reducer State Render Interactor Intents Result Intent
18. Repository Reducer State Render Interactor Intents Result Intent opens app
19. Repository Reducer State Render Interactor Intents Result Intent opens app resumeScreen()
20. Repository Reducer State Render Interactor Intents Result Intent opens app resumeScreen() get sessions request
21. Repository Reducer State Render Interactor Intents Result Intent opens app resumeScreen() get sessions request sessions list result
22. Repository Reducer State Render Interactor Intents Result Intent opens app resumeScreen() get sessions request sessions list result new state result 
 + 
 initial state
23. Repository Reducer State Render Interactor Intents Result Intent opens app resumeScreen() get sessions request
24. Repository Reducer State Render Interactor Intents Result Intent opens app resumeScreen() get sessions request sessions loading result
25. Repository Reducer State Render Interactor Intents Result Intent opens app resumeScreen() get sessions request sessions loading result result 
 + 
 initial state
26. Repository Reducer State Render Interactor Intents Result Intent opens app resumeScreen() get sessions request sessions loading result new state result 
 + 
 initial state
27. Repository Reducer State Render Interactor Intents Result Intent opens app resumeScreen() get sessions request sessions list result new state result 
 + 
 old state
28. Repository Reducer State Render Interactor Intents Result Intent opens app resumeScreen() get sessions request sessions error result new state result 
 + 
 old state
29. Loading Content Error
30. Repository Reducer State Render Interactor Intents Result Intent opens app resumeScreen() get sessions request sessions list result new state result 
 + 
 initial state
31. Repository Reducer State Render Interactor Intents Result Intent clicks on favorite
32. Repository Reducer State Render Interactor Intents Result Intent clicks on favorite saveFavoriteSession (id: String)
33. Repository Reducer State Render Interactor Intents Result Intent clicks on favorite saveFavoriteSession (id: String) save favorite session
34. Repository Reducer State Render Interactor Intents Result Intent clicks on favorite saveFavoriteSession (id: String) save favorite session session saved to favorites
35. Repository Reducer State Render Interactor Intents Result Intent clicks on favorite saveFavoriteSession (id: String) save favorite session session saved to favorites result 
 + 
 old state
36. Repository Reducer State Render Interactor Intents Result Intent clicks on favorite saveFavoriteSession (id: String) save favorite session session saved to favorites new state result 
 + 
 old state
37. Loading Content Error Idle
38. Repository Reducer State Render Interactor Intents Result Intent clicks on favorite saveFavoriteSession (id: String) save favorite session session saved to favorites new state result 
 + 
 old state
39. Mosby MVI 3.0
 
 by Hannes Dorfmann hannesdorfmann.com
41. demo time
 (because it’s 10:30AM and I don’t have time to draw another slide)
42. Pros and Cons • Single source of truth • Decoupling • Immutability • More info!!! (render history) • boilerplate code • steep learning curve • combining multiple streams can trigger unwanted renders • startWith { Result( ) } vs startWith( Result( ) )
43. Alternatives • https://github.com/airbnb/MvRx/ • https://github.com/freeletics/RxRedux • https://github.com/groupon/grox
44. Resources • MVI - http://hannesdorfmann.com/ • Redux-ing UI Bugs by Christina Lee - https:// www.youtube.com/watch?v=UsuzhTlccRk • { } vs ( ) https://medium.com/@ragdroid/rxify-the-startwith- mvi-pitfall-68764ae8946d • https://raw.githubusercontent.com/oldergod/android- architecture/todo-mvi-rxjava-kotlin/art/MVI_detail.png • https://github.com/AndroidIasi/Codecamp-2.0/tree/ presentation/cluj_181124
46. thank you!