Koin 3.2/Compose - injecting an activity-scoped viewmodel from a composable

Question

I have scoped a viewmodel to an activity like this:

    scope<MyActivity> {
      scoped<UseCase1> { UseCase1Impl(get()) }
      scoped<UseCase2> { UseCase2Impl(get()) }
      viewModel { parameters -> MyViewModel(parameters.get(), get(), get()) }
    }

In my activity I cannot access the viewmodel inside a composable with this call:

        setContent {

      val viewModel: MyViewModel by org.koin.androidx.compose.viewModel {
        ParametersHolder(mutableListOf("1"))
      }
      viewModel.doSomething() 
}

UNLESS I also do this outside the composable:

   private val viewModel by viewModel<CameraNameViewModel> { parametersOf("1") }

  override fun onCreate(savedInstanceState: Bundle?) {
    super.onCreate(savedInstanceState)
    viewModel // If I comment this, it crashes

   // setContent etc
}

The error is

 Caused by: org.koin.core.error.NoBeanDefFoundException: |- No definition found for class:'com.anonymised.path.to.MyViewModel'. Check your definitions!

Deep-diving with the debugger, it looks like the activities mViewmodelStore property is only populated when accessed outside the composable. I do have a workaround in that I can just inject every viewmodel in my top-level activity, but it doesn't seem right basically injecting it twice.

Answer 1

So you have two options:

---

Option 1: If your both your activity and your composable need the viewModel:

• Inject your viewModel into your activity like you already have

• just pass the viewModel to your composable

  class YourActivity : AppCompatActivity() {
      private val viewModel by viewModel<CameraNameViewModel> { parametersOf("1") }
  
      override fun onCreate(savedInstanceState: Bundle?) {
          super.onCreate(savedInstanceState)
  
          setContent {
              YourComposeScreen(viewModel)
          }
      }
  }
  
  @Composable fun YourComposeScreen(viewModel: CameraNameViewModel){
      /*your composable */
  }
  

---

Option 2: you only need your viewModel in your composable:

• don't inject the viewModel into your composable

• just use koins Compose-Syntax to inject the viewModel to your composable

  class YourActivity : AppCompatActivity() {
  
      override fun onCreate(savedInstanceState: Bundle?) {
          super.onCreate(savedInstanceState)
  
          setContent {
              YourComposeScreen() // <- we do not need any parameter here
          }
      }
  }
  
  @Composable fun YourComposeScreen(
      viewModel: CameraNameViewModel = getViewModel(parameters = { parametersOf("1") })
  ){
      /*your composable */
  }