Showing Items from Room with Jetpack Compose

Question

I am trying to show items from my room database with JetPack Compose like in this example.

My Entity:

@Entity(tableName = "trains")
data class TrainSearch(
    @PrimaryKey(autoGenerate = true)
    override var id: Long = 0L,
    var type: TrainType = TrainType.ICE,
    var number: String = "",
    override var name: String? = null
) : Listable {}

My Repository:

class ListableRepositoryImpl(private val trainSearchDao: TrainSearchDao) : ListableRepository {
    override fun fetchAllItems(): Flow<TrainSearch> {
        return trainSearchDao.getAllTrainSearches()
    }
}

My ViewModel:

class FavListViewModel(private val homeRepo: ListableRepository) : ViewModel() {

    val savedItems = homeRepo.fetchAllItems()
}

My Compose Function:

(...)
import androidx.compose.runtime.collectAsState
import androidx.compose.runtime.getValue
(...)

fun FavListScreen(
    modifier: Modifier = Modifier,
    favListViewModel: FavListViewModel = koinViewModel()
) {

    val savedItems:List<TrainSearch> by favListViewModel.savedItems.collectAsState(initial = emptyList<TrainSearch>())
(...)

But I am getting the Error Message, that getValue is not suitable. And I have no Idea why. :(

Can anyone point me into the right direction?

Answer 1

I figured it out after a lot of debugging and logging sessions. I was using the wrong type Flow<TrainSearch>. In the example the Author uses typealias Books = List<Book>. This was misleading me. I had to use Flow<List<TrainSearch>>.