Touching motif - DI library for Android and Java applications

I have talked about uber/motif library which provides simple API for dependency injection at potatotips#54.

uber/motif: A simple DI API for Android / Java
https://github.com/uber/motif

Transcript

1. uber/motif
   @shaunkawano
   

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2. •DI library - simple API optimized for
   nested scopes
   •Generates Dagger code for actual
   DI
   •Under heavily development
   uber/motif
   

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4. Usage
   

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5. @motif.Scope
   interface AppScope {
   @motif.Objects
   abstract class Objects {
   fun okHttpClient(): OkHttpClient = 

   OkHttpClient.Builder().build()
   fun retrofit(okHttpClient: OkHttpClient): Retrofit =
   Retrofit.Builder().client(okHttpClient).baseUrl("")
   .addCallAdapterFactory(RxJava2CallAdapterFactory.createAsync())
   .build()
   fun service(retrofit: Retrofit): Service =
   retrofit.create(Service::class.java)
   fun api(service: Service): Api = ApiClient(service)
   }
   }
   

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6. @motif.Scope
   interface AppScope {
   @motif.Objects
   abstract class Objects {
   fun okHttpClient(): OkHttpClient = 

   OkHttpClient.Builder().build()
   fun retrofit(okHttpClient: OkHttpClient): Retrofit =
   Retrofit.Builder().client(okHttpClient).baseUrl("")
   .addCallAdapterFactory(RxJava2CallAdapterFactory.createAsync())
   .build()
   fun service(retrofit: Retrofit): Service =
   retrofit.create(Service::class.java)
   fun api(service: Service): Api = ApiClient(service)
   }
   }
   

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7. @motif.Scope
   interface AppScope {
   @motif.Objects
   abstract class Objects {
   fun okHttpClient(): OkHttpClient = 

   OkHttpClient.Builder().build()
   fun retrofit(okHttpClient: OkHttpClient): Retrofit =
   Retrofit.Builder().client(okHttpClient).baseUrl("")
   .addCallAdapterFactory(RxJava2CallAdapterFactory.createAsync())
   .build()
   fun service(retrofit: Retrofit): Service =
   retrofit.create(Service::class.java)
   fun api(service: Service): Api = ApiClient(service)
   }
   }
   

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8. @motif.Scope
   interface AppScope {
   @motif.Objects
   abstract class Objects {
   fun okHttpClient(): OkHttpClient = 

   OkHttpClient.Builder().build()
   fun retrofit(okHttpClient: OkHttpClient): Retrofit =
   Retrofit.Builder().client(okHttpClient).baseUrl("")
   .addCallAdapterFactory(RxJava2CallAdapterFactory.createAsync())
   .build()
   fun service(retrofit: Retrofit): Service =
   retrofit.create(Service::class.java)
   fun api(service: Service): Api = ApiClient(service)
   }
   }
   

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11. public class AppScopeImpl implements AppScope {
    private final Component component;
    public AppScopeImpl(Dependencies dependencies) {
    this.component = DaggerAppScopeImpl_Component.builder()
    .dependencies(dependencies)
    .module(new Module())
    .build();
    }
    public AppScopeImpl() {
    this(new Dependencies() {});
    }
    public interface Dependencies {
    }
    @DaggerScope
    @dagger.Component(
    dependencies = Dependencies.class,
    modules = Module.class
    )
    interface Component {
    }
    private static class Objects extends AppScope.Objects {
    }
    …
    

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12. @dagger.Module
    class Module {
    private final AppScope.Objects objects = new Objects();
    @Provides
    AppScope appScope() {
    return AppScopeImpl.this;
    }
    @Provides
    @DaggerScope
    OkHttpClient okHttpClient() {
    return objects.okHttpClient();
    }
    @Provides
    @DaggerScope
    Retrofit retrofit(OkHttpClient okHttpClient) {
    return objects.retrofit(okHttpClient);
    }
    @Provides
    @DaggerScope
    Service service(Retrofit retrofit) {
    return objects.service(retrofit);
    }
    …
    }
    

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14. public final class AppScopeImpl_Module_ApiFactory implements Factory {
    private final AppScopeImpl.Module module;
    private final Provider serviceProvider;
    public AppScopeImpl_Module_ApiFactory(
    AppScopeImpl.Module module, Provider serviceProvider) {
    this.module = module;
    this.serviceProvider = serviceProvider;
    }
    @Override
    public Api get() {
    return provideInstance(module, serviceProvider);
    }
    public static Api provideInstance(AppScopeImpl.Module module, Provider
    serviceProvider) {
    return proxyApi(module, serviceProvider.get());
    }
    …
    public static Api proxyApi(AppScopeImpl.Module instance, Service service) {
    return Preconditions.checkNotNull(
    instance.api(service), "Cannot return null from a non-@Nullable @Provides
    method");
    }
    }
    

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15. It generates code similar to
    or the same as what dagger
    generates
    

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16. dagger & motif?
    

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17. # of concepts
    

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18. @RootComponent.Scope
    @Component(modules = RootComponent.Module.class)
    public interface RootComponent {
    RootController controller();
    LoggedInComponent.Builder loggedIn();
    @dagger.Component.Builder
    interface Builder {
    @BindsInstance
    Builder viewGroup(@Root ViewGroup parent);
    RootComponent build();
    }
    @dagger.Module
    abstract class Module {
    @Scope
    @Provides
    static RootView view(@Root ViewGroup parent) {
    return RootView.create(parent);
    }
    }
    @javax.inject.Scope
    @interface Scope {}
    @Qualifier
    @interface Root {}
    }
    

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19. @RootComponent.Scope
    @Component(modules = RootComponent.Module.class)
    public interface RootComponent {
    RootController controller();
    LoggedInComponent.Builder loggedIn();
    @dagger.Component.Builder
    interface Builder {
    @BindsInstance
    Builder viewGroup(@Root ViewGroup parent);
    RootComponent build();
    }
    @dagger.Module
    abstract class Module {
    @Scope
    @Provides
    static RootView view(@Root ViewGroup parent) {
    return RootView.create(parent);
    }
    }
    @javax.inject.Scope
    @interface Scope {}
    @Qualifier
    @interface Root {}
    }
    •@Scope
    •@Component / @Subcomponent
    •@Component.Buidler / @Subcomponent.Builder
    •@Qualifier
    •@BindsInstance
    •@Module
    •@Provides
    •abstract @Modules
    •static @Provides
    •Component provision method
    •Component factory method
    •Constructor injection
    

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20. @Scope
    public interface RootScope {
    RootController controller();
    LoggedInScope loggedIn(ViewGroup parentViewGroup);
    @motif.Objects
    abstract class Objects {
    abstract RootController controller();
    RootView view(ViewGroup viewGroup) {
    return RootView.create(viewGroup);
    }
    }
    }
    

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21. @Scope
    public interface RootScope {
    RootController controller();
    LoggedInScope loggedIn(ViewGroup parentViewGroup);
    @motif.Objects
    abstract class Objects {
    abstract RootController controller();
    RootView view(ViewGroup viewGroup) {
    return RootView.create(viewGroup);
    }
    }
    }
    •@motif.Scope
    •@motif.Objects
    •Access method
    •Child method
    •Factory method (Basic)
    •Factory method (Constructor Injected)
    

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22. •dagger
    •Fully customizable
    •Required to understand its concepts
    •Code readability concern
    •motif
    •Less customizable
    •Less concepts
    •More readable
    Philosophy
    

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23. @Expose
    

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24. @motif.Scope
    interface ChildScope {
    @motif.Objects
    open class Objects {
    fun childService(retrofit: Retrofit): ChildService =
    retrofit.create(ChildService::class.java)
    fun childApi(childService: ChildService): ChildApi =
    ChildApiClient(childService)
    }
    }
    

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25. @motif.Scope
    interface ChildScope {
    @motif.Objects
    open class Objects {
    fun childService(retrofit: Retrofit): ChildService =
    retrofit.create(ChildService::class.java)
    fun childApi(childService: ChildService): ChildApi =
    ChildApiClient(childService)
    }
    }
    

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26. @motif.Scope
    interface AppScope {
    fun childScope(): ChildScope
    @motif.Objects
    open class Objects {
    fun okHttpClient(): OkHttpClient =
    OkHttpClient.Builder().build()
    fun retrofit(okHttpClient: OkHttpClient): Retrofit =
    Retrofit.Builder().client(okHttpClient).baseUrl(“")
    .addCallAdapterFactory(RxJava2CallAdapterFactory
    .createAsync()).build()
    fun service(retrofit: Retrofit): Service =
    retrofit.create(Service::class.java)
    fun api(service: Service): Api = ApiClient(service)
    }
    }
    

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27. @motif.Scope
    interface AppScope {
    fun childScope(): ChildScope
    @motif.Objects
    open class Objects {
    fun okHttpClient(): OkHttpClient =
    OkHttpClient.Builder().build()
    fun retrofit(okHttpClient: OkHttpClient): Retrofit =
    Retrofit.Builder().client(okHttpClient).baseUrl(“")
    .addCallAdapterFactory(RxJava2CallAdapterFactory
    .createAsync()).build()
    fun service(retrofit: Retrofit): Service =
    retrofit.create(Service::class.java)
    fun api(service: Service): Api = ApiClient(service)
    }
    }
    

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29. @Expose
    

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30. @motif.Scope
    interface AppScope {
    fun childScope(): ChildScope
    @motif.Objects
    open class Objects {
    fun okHttpClient(): OkHttpClient =
    OkHttpClient.Builder().build()
    fun retrofit(okHttpClient: OkHttpClient): Retrofit =
    Retrofit.Builder().client(okHttpClient).baseUrl(“")
    .addCallAdapterFactory(RxJava2CallAdapterFactory
    .createAsync())
    .build()
    fun service(retrofit: Retrofit): Service =
    retrofit.create(Service::class.java)
    fun api(service: Service): Api = ApiClient(service)
    }
    }
    

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31. @motif.Scope
    interface AppScope {
    fun childScope(): ChildScope
    @motif.Objects
    open class Objects {
    fun okHttpClient(): OkHttpClient =
    OkHttpClient.Builder().build()
    @Expose
    fun retrofit(okHttpClient: OkHttpClient): Retrofit =
    Retrofit.Builder().client(okHttpClient).baseUrl("")
    .addCallAdapterFactory(RxJava2CallAdapterFactory
    .createAsync())
    .build()
    fun service(retrofit: Retrofit): Service =
    retrofit.create(Service::class.java)
    fun api(service: Service): Api = ApiClient(service)
    }
    }
    

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32. Summary
    

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33. •DI library
    •Clearly different from Dagger
    •Under heavily development
    •Read and understand its philosophy
    before choosing to use it or not
    uber/motif
    

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34. Uber/Motif
    @shaunkawano
    Thank you!
    

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