dependency injection - Koin how to inject outside of Android activity / appcompatactivity

Question

Koin is a new, lightweight library for DI and can be used in Android as well as in standalone kotlin apps.

Usually you inject dependencies like this:

class SplashScreenActivity : Activity() {

    val sampleClass : SampleClass by inject()

    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
    }
}

with the inject() method.

But what about injecting stuff in places where Activity context is not available i.e. outside of an Activity?

Answer 1

There is the KoinComponent which comes to the rescue. In any class you can simply:

class SampleClass : KoinComponent {

    val a : A? by inject()
    val b : B? by inject()
}

Extending KoinComponent gives you access to inject() method.

Remember that usually it's enough to inject stuff the usual way:

class SampleClass(val a : A?, val b: B?)