android-viewmodel

Expose UI state from an Android ViewModel using StateFlow by backing a public StateFlow<T> with a private MutableStateFlow<T>, initializing it with a default value to ensure predictable state management and separation of concerns.

The best way to handle one-off events in Android MVVM is using SharedFlow with replay = 0, ensuring transient events like navigation or toasts are emitted only once without re-triggering when the UI recomposes or rotates.

Collect StateFlow safely with lifecycle awareness in Compose using the collectAsStateWithLifecycle extension, which pauses collection when the app enters the background and prevents unnecessary emissions.

Use SharedFlow instead of StateFlow for ViewModel events when dealing with transient, one-off occurrences like navigation or toast messages, as SharedFlow with replay = 0 prevents redundant emission unlike StateFlow which retains the latest value.

Trigger ViewModel coroutines for state updates by launching them within viewModelScope, allowing asynchronous data fetching and processing to safely update the private MutableStateFlow without leaking lifecycle-bound operations.