MVVM com RxJava com Kotlin

Iremos falar sobre a arquitetura MVVM(Model/View/ViewModel) no Android usando RxJava com Kotlin.

Transcript

1. MVVM com RxJava em Kotlin no
   Android
   

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2. GDGFoz
   Quem ?
   • Houssan Ali Hijazi - hussanhijazi@gmail.com
   • Desenvolvedor Android na www.HElabs.com
   • Organizador GDG Foz do Iguaçu
   • www.lojasnoparaguai.com.br
   • www.desaparecidosbr.org
   • www.hussan.com.br
   

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3. GDGFoz
   Kotlin
   • 2011/JetBrains
   • 1.0 em Fev. 2016
   • 1.1 em Mar. 2017
   • Pinterest, Coursera, Netflix, Uber, Square, Trello e
   Basecamp
   • 17/Maio - Google IO 2017
   

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4. GDGFoz
   Kotlin
   • Interoperabilidade
   • Null Safety
   • Conciso
   

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5. GDGFoz
   Manifesto reativo
   • Responsivo - Reagir rápido
   • Resiliente - Reagir a falhas
   • Elástico - Reagir a carga / Autoescalar
   • Orientado a mensagens - Comunicação
   assíncrona
   Fonte: https://www.reactivemanifesto.org/pt-BR
   

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6. GDGFoz
   RxJava
   • RxJava - Reactive Extensions para a JVM - uma
   biblioteca para compor programas assíncronos e
   baseados em eventos usando sequências
   observáveis.
   • Netflix
   • 1.0.0 em 18 Nov 2014
   • 2.0.0 em 28 Out 2016
   

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7. GDGFoz
   RxJava
   Observable
   Disposable
   subscribe(Observer)
   Emite
   Observer
   onNext(T)
   onComplete()
   onError(Throwable)
   Consome
   

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8. GDGFoz
   RxJava
   • Observable - Emite dados
   • Observer - Consome dados
   • Disposable
   • Operators: map, flatmap, filter, last, first etc..
   • Schedulers
   

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9. GDGFoz
   Código
   • Robusto
   • Estável
   • Testável
   • Modular
   

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10. GDGFoz
    Model/View/Controller
    Activity
    IView
    

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11. GDGFoz
    Model/View/Presenter
    Contract
    

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12. GDGFoz
    App
    

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13. GDGFoz
    Model/View/Presenter
    // View contract
    interface RepositoriesContract{
    interface View{
    fun setRepositories(repositories: List)
    }
    }
    // Activity/Fragment
    class RepositoriesActivity : AppCompatActivity(), RepositoriesContract.View {
    ...
    // Passing the View to Presenter
    presenter = RepositoriesPresenter(this)
    override fun setRepositories(repositories: List) {
    // Setting data to view
    }
    

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14. GDGFoz
    Model/View/Presenter
    // Presenter contract
    interface RepositoriesContract {
    interface Presenter {
    fun getAllRepositories()
    }
    }
    // Passing View to Presenter
    class RepositoriesPresenter(val view: RepositoriesContract.View): RepositoriesContract.Presenter
    lateinit var model: RepositoryModel
    override fun getAllRepositories() {
    // Call model and set data to View
    // Can be RxJava
    var repositories:List = model.getAllRepositories()
    view.setRepositories(repositories)
    }
    

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15. GDGFoz
    Model/View/ViewModel
    • Microsoft
    • 2005
    • Orientado à eventos
    

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16. GDGFoz
    Model/View/ViewModel
    

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17. GDGFoz
    MVVM
    // ViewModel
    class RepositoriesViewModel(var model: RepositoryDataSource) {
    ...
    fun getAllRepositories() {
    // Return an Observable
    fun getAllRepositories(): Observable> = model.getAllRepositories()
    }
    

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18. GDGFoz
    MVVM
    // Activity/Fragment
    class RepositoriesActivity : AppCompatActivity() {
    private val viewModel: RepositoriesViewModel by lazy {
    RepositoriesViewModel(RepositoryModel())
    }
    private val mDisposable = CompositeDisposable()
    ...
    

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19. GDGFoz
    MVVM
    // Activity/Fragment
    override fun onCreate(savedInstanceState: Bundle?) {
    ...
    mDisposable.add(
    viewModel.getAllRepositories()
    .subscribeOn(Schedulers.io())
    .observeOn(AndroidSchedulers.mainThread())
    .subscribe(
    // onNext
    this::setRepositories,
    // onError
    { error -> Log.d(TAG, "Error: ", error) },
    // onComplete
    { Log.d(TAG, "Completed: ") }
    )
    )
    // Activity/Fragment
    fun setRepositories(repositories: List) {
    // Setting data to view
    }
    

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20. GDGFoz
    Android lifecycle
    // Activity/Fragment
    override fun onDestroy() {
    super.onDestroy()
    mDisposable.dispose()
    }
    

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21. GDGFoz
    MVP/MVVM
    class Presenter: IPresenter {
    override fun getAllRepositories() {
    ...
    view.setRepositories(repositories)
    }
    }
    class ViewModel {
    fun getAllRepositories(): Observable> {
    ...
    }
    }
    

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22. GDGFoz
    MVVM tests
    class RepositoriesViewModelTest {
    @Mock
    lateinit var model: RepositoryDataSource
    lateinit var viewModel: RepositoriesViewModel
    …
    @Before
    fun setup()
    {
    model = mock()
    viewModel = RepositoriesViewModel(model)
    }
    

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23. GDGFoz
    MVVM tests
    @Test
    fun `get repositories emit correct values`() {
    val repositories = listOf(Repository(name = "Test"), Repository(name = "Test2"
    `when`(model.getAllRepositories()).thenReturn(Observable.just(repositories))
    viewModel.getAllRepositories()
    .test()
    .assertNoErrors()
    .assertComplete()
    .assertValue(repositories)
    }
    

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24. GDGFoz
    Save states
    // Save
    override fun onSaveInstanceState(state: Bundle?) {
    super.onSaveInstanceState(state)
    //Can create Bundle here
    state.putAll(viewModel.getState())
    }
    // Restore
    override fun onRestoreInstanceState(bundle: Bundle) {
    super.onRestoreInstanceState(bundle)
    viewModel.restoreState(bundle)
    }
    

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25. GDGFoz
    Activity
    Fragment
    CustomView
    CustomView
    P / VM
    View
    

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26. GDGFoz
    Lógica de UI ?
    • Tem lógica de UI ?
    • Sim - Presenter/ViewModel (Testes)
    • Não - View
    

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27. GDGFoz
    Qual ?
    • Classes Android sem lógica ?
    • Pode ser testado (unit test) ?
    • Suas classes tem uma responsabilidade bem
    definida ?
    

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28. GDGFoz
    Links
    • http://reactivex.io/
    • https://github.com/ReactiveX/RxJava/
    • https://kotlinlang.org/
    • https://medium.com/upday-devs/android-architecture-patterns-part-3-
    model-view-viewmodel-e7eeee76b73b
    • https://github.com/googlesamples/android-architecture
    • https://github.com/hussanhijazi/retrofit-rxjava-databinding/tree/kotlin-mvvm
    

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29. Obrigado
    

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