android-viewmodel

SKILL.md

Android ViewModel & State Management

Instructions

Use ViewModel to hold state and business logic. It must outlive configuration changes.

1. UI State (StateFlow)

What: Represents the persistent state of the UI (e.g., Loading, Success(data), Error).

Type: StateFlow<UiState>.

Initialization: Must have an initial value.

Exposure: Expose as a read-only StateFlow backing a private MutableStateFlow.
private val _uiState = MutableStateFlow<UiState>(UiState.Loading)
val uiState: StateFlow<UiState> = _uiState.asStateFlow()

Updates: Update state using .update { oldState -> ... } for thread safety.