modern-app-patterns

DI with Hilt

Use Hilt for constructor injection and module-provided dependencies.

Example

// App.kt
@HiltAndroidApp
class App: Application()

// NetworkModule.kt
@Module
@InstallIn(SingletonComponent::class)
object NetworkModule {
  @Provides @Singleton fun okHttp(): OkHttpClient = OkHttpClient.Builder().build()
  @Provides @Singleton fun retrofit(client: OkHttpClient): Retrofit =
    Retrofit.Builder().baseUrl("https://example.com").client(client).addConverterFactory(MoshiConverterFactory.create()).build()
  @Provides @Singleton fun api(retrofit: Retrofit): Api = retrofit.create(Api::class.java)
}

// RepoModule.kt
@Module
@InstallIn(SingletonComponent::class)
object RepoModule {
  @Provides fun todosRepo(api: Api, dao: TodoDao): TodosRepo = TodosRepoImpl(api, dao)
}

Notes

• Keep bindings in feature modules when possible.

Sandbox copy map

Paste into Android Studio project (see sandboxes/android-compose):

• App.kt — annotate your Application with @HiltAndroidApp.
• di/NetworkModule.kt and di/RepoModule.kt — provide Retrofit/OkHttp/Api and repositories.
• ViewModels — use @HiltViewModel and obtain instances with hiltViewModel() in composables.
• Gradle — apply Hilt plugin and add dependencies in your module and project build files.

This site is open source. Improve this page.