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Constructor DSL for Android

New Constructor DSL (Since 3.2)​

Koin now offer a new kind of DSL keyword that allow you to target a class constructor directly, and avoid to have type your definition within a lambda expression.

Check the new Constructor DSL section for more details.

For Android, this implies the following new constructor DSL Keyword:

  • viewModelOf() - equivalent of viewModel { }
  • fragmentOf() - equivalent of fragment { }
  • workerOf() - equivalent of worker { }
info

Be sure to use :: before your class name, to target your class constructor

An Android 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 Constructor DSL above