Autowire DSL for Android

This guide covers Android-specific autowire DSL extensions. For core autowire DSL concepts (singleOf, factoryOf, scopedOf), see Autowire DSL.

info

Naming Note: This feature was previously called "Constructor DSL" in earlier documentation. Both terms refer to the same capability.

Android-Specific Keywords

In addition to the core autowire DSL keywords, Koin provides Android-specific keywords for common Android components:

• viewModelOf() - equivalent of viewModel { } - declare a ViewModel
• fragmentOf() - equivalent of fragment { } - declare a Fragment (when using Fragment Factory)
• workerOf() - equivalent of worker { } - declare a WorkManager Worker

Complete Example

Given an Android application with the following components:

// A simple service
class SimpleServiceImpl() : SimpleService

// a Presenter, using SimpleService and can receive "id" injected param
class FactoryPresenter(val id: String, val service: SimpleService)

// a ViewModel that can receive "id" injected param, use SimpleService and get SavedStateHandle
class SimpleViewModel(val id: String, val service: SimpleService, val handle: SavedStateHandle) : ViewModel()

// a scoped Session, that can received link to the MyActivity (from scope)
class Session(val activity: MyActivity)

// a Worker, using SimpleService and getting Context & WorkerParameters
class SimpleWorker(
    private val simpleService: SimpleService,
    appContext: Context,
    private val params: WorkerParameters
) : CoroutineWorker(appContext, params)

we can declare them like this:

module {
    singleOf(::SimpleServiceImpl){ bind<SimpleService>() }

    factoryOf(::FactoryPresenter)

    viewModelOf(::SimpleViewModel)

    scope<MyActivity>(){
        scopedOf(::Session)
    }

    workerOf(::SimpleWorker)
}

Android Reflection DSL (Deprecated since 3.2)

caution

Koin Reflection DSL is now deprecated. Please use Koin Autowire DSL above