Android State Management

---
name: android-state-management
description: Standards for ViewModel, StateFlow, and UI State Patterns
metadata:
  labels: [android, state, viewmodel, flow]
  triggers:
    files: ['**/*ViewModel.kt', '**/*UiState.kt']
    keywords: [viewmodel, stateflow, livedata, uistate]
---

# Android State Management

## **Priority: P0**

## Implementation Guidelines

### ViewModel Pattern

- **Exposure**: Expose ONE `StateFlow<UiState>` via `.asStateFlow()`.
- **Scope**: Use `viewModelScope` for all coroutines.
- **Initialization**: Trigger initial load in `init` or `LaunchedEffect` (once).

### UI State (LCE)

- **Type**: sealed interface `UiState` (Loading, Content, Error).
- **Immutability**: Data classes inside should be `@Immutable`.

### Flow Lifecycle

- **Collection**: Use `collectAsStateWithLifecycle()` in Compose.
- **Hot Flows**: Use `SharingStarted.WhileSubscribed(5000)` for shared resources.

## Anti-Patterns

- **LiveData**: `**No LiveData**: Use StateFlow.`
- **Mutable State**: `**No Mutable Public**: Expose read-only Flow.`
- **Context**: `**No Context in VM**: Memory Leak Risk.`

## References

- [Templates](references/implementation.md)