Wrapping a `Flow<List<Entity>>` I get ...

# compose

[Filip Stanis]

Wrapping a Flow<List<Entity>> I get from Room into either a SharedFlow or a StateFlow seems to prevent it from working (I get the initial list of items from Room, but it never updates). What could be causing this?

(code in first reply)

[Filip Stanis]

In my composable: val state = viewModel.state.collectAsState(State()) in every situation.

// This works as expected
val state = repository.getAll().map { State(items = it) }

// StateFlow - this doesn't
val state = repository.getAll().map { State(items = it) }.stateIn(viewModelScope, WhileSubscribed(5000), State())

// SharedFlow - same as StateFlow
val state = repository.getAll().map { State(items = it) }.shareIn(viewModelScope, WhileSubscribed(5000), 1)

(I'm aware I'm exposing a mutable flow here, that's just to keep the example simple)

[corneil]

How are you updating the state at source?

[Filip Stanis]

it's directly from my Room DAO:

interface MyDao {
    @Query("SELECT * FROM Entity ORDER BY timestamp DESC")
    fun getAll(): Flow<List<Entity>>
}

[corneil]

Shouldn't you be using getAll().collect in order to let the flow emit values.

[Filip Stanis]

OK, I found the issue is because I forgot to make my repository / DB a @Singleton. Why this caused an issue only for a StateFlow / stateIn is a mystery.

[Chris Fillmore]

For future reference there is #room

[Filip Stanis]

Thanks, I was convinced this is a compose / flow issue when I wrote it 😕