android-state

name

android-state

description

Configure ViewModel state emission with StateFlow, sealed UiState classes, and lifecycle-safe collection in Android. Use when working with ViewModel files, UiState sealed classes, MutableStateFlow, collectAsStateWithLifecycle, or exposing state from ViewModels. (triggers: **/*ViewModel.kt, **/*UiState.kt, viewmodel, stateflow, livedata, uistate, MutableStateFlow, collectAsState, viewModelScope, UiState)

Android State Management

Priority: P0

1. Structure the ViewModel

• Expose ONE StateFlow<UiState> via .asStateFlow().
• Use viewModelScope for all coroutines.
• Trigger initial load in init block.

See templates for ViewModel and UiState examples.

2. Define UI State (LCE Pattern)

• Use sealed interface with Loading, Content, Error variants.
• Data classes inside should be @Immutable.

See templates for sealed UiState pattern.

3. Collect State Lifecycle-Safely

• Use collectAsStateWithLifecycle() in Compose.
• Use SharingStarted.WhileSubscribed(5000) for shared resources.

Anti-Patterns

• No LiveData for New Code: Use StateFlow — lifecycle-safe and Compose-compatible.
• No Public MutableStateFlow: Expose only .asStateFlow() to consumers.
• No Context in ViewModel: Leaks Activity. Use Application context if truly needed.

References

• Templates