As presented in droidcon Tel Aviv 2018: http://il.droidcon.com

1. Who needs MVVM? Architecture components & MVP!

2. Timor Surkis | TSurkis.com
Mobile Software Engineer
Fundamentals Squad &
Mentor

3. Disclaimers

4. Prelude

5. MVP or MVVM?

6. MVP
MyAPP

7. MVP
View Presenter Data
Controller
onReceived(...)
GetListSize()
getItem(...)
onUpdate(...)
onDelete(...)

8. MVP | ListAdapter
ListAdapter
DiffUtil.ItemCallback<T>
List<T>List<T>
MyAPP

9. View Presenter Data
ControlleronReceived(...)
GetListSize()
getItem(...)
onUpdate(...)
onDelete(...)
MVP | ListAdapter

10. MVP | LiveData
LiveData<T>Observer<T>
Activity
Fragment
Forever
Lifecycle

11. LiveData<T>
ObserverWrapper
MVP | LiveData
Map of
Observer<T>
ObserverWrapper : GenericLifecycleObserver
AlwaysActiveObserverLifecycleBoundObserver
LifecycleOwner
Observer<T>
Observer<T>

12. MVP | LiveData
ActivityFragment* : LifecycleOwner
LifecycleRegistry
LifecycleBoundObserver
as
LifecycleObserver
ObserverWithState
Map of
State
LifecycleObserver
* FragmentActivity/ Fragment(support libraries)

13. View
loadList(data: List<T>)
getLifecycleOwnerInstance() = this
MVP | LiveData

14. DataController
bindData(
lifecycleOwner: LifecycleOwner,
newDataBlock: (List<T>) -> Unit
)
MVP | LiveData
data: MutableLiveData<T>

15. Presenter
onBusinessLogicReady() {
dataController.bindData(
screen.getLifeCycleOwnerInstance(),
screen::loadList
)
...
}
MVP | LiveData

16. MVP | LiveData
View
ListAdapter
DiffUtil.ItemCallback<T>
List<T>
DataController
LiveData<T>
Repository

17. MVP
MyAPP
?

18. lifecycle
aware
Presenter
MVP | Lifecycle
onCreate
onStart
onResume
onPause
onStop
onDestroy
onCreate
onStart
onResume
onPause
onStop
onDestroy
create
rotate
finish
ViewModel
onCleared
Presenter

19. BasePresenter
MVP | Lifecycle
abstract class BasePresenter<ScreenType>(
protected val screen: ScreenType
)

20. BasePresenter
MVP | Lifecycle
abstract class BasePresenter<ScreenType> {
private var screen: WeakReference<ScreenType>? = null
fun attach(screen: ScreenType) {
this.screen = WeakReference(screen)
}
protected fun getScreen(): ScreenType? = screen?.get()
}

21. BasePresenter
MVP | Lifecycle
abstract class BasePresenter<ScreenType> {
private var screen: WeakReference<ScreenType>? = null
fun attach(screen: ScreenType) {
this.screen = WeakReference(screen)
}
protected fun getScreen(): ScreenType? = screen?.get()
}

22. BasePresenter
MVP | Lifecycle
abstract class BasePresenter<ScreenType> {
private var screen: WeakReference<ScreenType>? = null
fun attach(screen: ScreenType) {
this.screen = WeakReference(screen)
}
protected fun getScreen(): ScreenType? = screen?.get()
}

23. Activity Fragment
MVP | Lifecycle
...
presenter = /* Initialization */
presenter.attach(this)
...

24. Activity Fragment
MVP | Lifecycle
ViewModelProviders
.of(this, viewModelFactory)
.get(SomeViewModel::class.java)

25. MVP | Lifecycle
ActivityFragment* : ViewModelStoreOwner
ViewModelStore
String
Map of
* FragmentActivity/ Fragment(support libraries)
ViewModel

26. MVP | Lifecycle
of( ),ActivityFragment Factory
ViewModelProvider
ViewModelStore Factory
ViewModelStoreOwner
.getViewModelStore()

27. MVP | Lifecycle
ViewModelProvider
ViewModelStore Factory
.get(ViewModelClass)

28. MVP | Lifecycle
ViewModelProvider.Factory
@NonNull
<T extends ViewModel> T create(@NonNull Class<T> modelClass);

29. MVP | Lifecycle
SimpleFactory : ViewModelProvider.Factory
override fun <T : ViewModel?> create(modelClass: Class<T>): T {
when (modelClass) {
QuotesPresenter::class.java -> {
return QuotesPresenter(QuotesInteractor(quotesRepository))
}
...
}
...
}

30. MVP | Lifecycle
SimpleFactory : ViewModelProvider.Factory
override fun <T : ViewModel?> create(modelClass: Class<T>): T {
when (modelClass) {
QuotesPresenter::class.java -> {
return QuotesPresenter(QuotesInteractor(quotesRepository))
}
...
}
...
}

31. MVP | Lifecycle
SimpleFactory : ViewModelProvider.Factory
override fun <T : ViewModel?> create(modelClass: Class<T>): T {
when (modelClass) {
QuotesPresenter::class.java -> {
return QuotesPresenter(QuotesInteractor(quotesRepository))
}
...
}
...
}

32. MVP | Lifecycle
PresenterModule
@Module
abstract class PresenterModule {
@Binds
@IntoMap
@PresenterKey(QuotesPresenter::class)
abstract fun provideQuotesViewModel(
quotesViewModel: QuotesPresenter
): ViewModel
...
}

33. MVP | Lifecycle
PresenterFactory : ViewModel.Factory
ViewModelClass
Map of
Provider<ViewModel>

34. MVP | Lifecycle
ViewModel
protected void onCleared() {
}

35. BasePresenter
MVP | Lifecycle
abstract class BasePresenter<ScreenType> : ViewModel() {
private var screen: WeakReference<ScreenType>? = null
fun attach(screen: ScreenType) {
this.screen = WeakReference(screen)
}
protected fun getScreen(): ScreenType? = screen?.get()
}

36. Activity Fragment
MVP | Lifecycle
presenter = ViewModelProviders
.of(this, presenterFactory)
.get(SomePresenter::class.java)
presenter.attach(this)

37. MVP | Conclusion
Regular MVP:
https://github.com/TSurkis/AppinionMVP
MVP & LiveData:
https://github.com/TSurkis/AppinionMVP/tree/livedata_integrat
ion
MVP & LiveData & Lifecycle
https://github.com/TSurkis/AppinionMVP/tree/lifecycle_integrat
ion_by_presenter_as_viewmodel

38. MVVM
ViewModel
Repository
View ?

39. MVVM
MVPMVVM
M?|View|ViewModel M?|View|Presenter
MVVM MVP

40. MVVM Contract
interface QuotesScreenContract {
interface Screen {
fun showProgressBar()
fun hideProgressBar()
fun showList()
fun hideList()
fun loadList(quotes: List<Quote>)
}
interface Presenter { ... }
interface Interactor { ... }
}

41. MVVM
Screen
showProgressBar()
hideProgressBar()
showList()
hideList()
loadList(quotes: List<Quote>)
ScreenState
showProgressBar: Boolean
showListOfQuotes: Boolean
LiveData<Quote>

42. MVVM
ViewModel
Repository
LiveData<ScreenState>
LiveData<Data>
View
ListAdapter

43. MVVM | Conclusion
MVVM with a touch of MVP:
https://github.com/TSurkis/AppinionMVVM

44. Conclusion

45. Credits
Medium Article:
https://medium.com/@t.surkiss/architecture-components-mvp-mvvm-237eaa83109
6
Hannes Dorfman:
http://hannesdorfmann.com/android/mosby3-mvi-1
MVP:
https://github.com/TSurkis/AppinionMVP
MVVM:
https://github.com/TSurkis/AppinionMVVM
Presentation Image:
https://unsplash.com/photos/3Ijt7UkSBYE