android-viewmodel

To manage persistent UI state across configuration changes, use a ViewModel with StateFlow. Store your state in a private backing MutableStateFlow and expose a public read-only StateFlow to ensure the state survives lifecycle events safely.

The best way to handle one-off events like navigation or toasts is using SharedFlow with replay = 0. This ensures transient events are emitted only once and are not duplicated when configuration changes recreate the UI.

Stale values after rotation often occur when state is not properly lifecycle-safe. Using a ViewModel with StateFlow as a UI state container with an initial value ensures the state persists correctly during configuration changes.

No, you should use separate flows. Use StateFlow for persistent UI state with an initial value and SharedFlow with replay = 0 for one-off events. This separation keeps your Android ViewModel state and event management clean.

To expose a read-only StateFlow, create a private MutableStateFlow as a backing property and expose it as a public StateFlow. This pattern prevents external modifications while allowing the Android ViewModel to update the UI state internally.

Yes, using viewModelScope and coroutines provides lifecycle-safe and testable patterns for StateFlow UI state. This approach ensures your Android ViewModel manages state and one-off events correctly during asynchronous operations.