Jetpack Compose: State Management Best Practices

State management is crucial in Jetpack Compose. Let's explore the best practices I've learned from production apps.

Understanding State in Compose

In Compose, state is any value that can change over time. When state changes, Compose automatically recomposes the UI.

State Hoisting

Always hoist state to the lowest common ancestor:

@Composable
fun SearchScreen() {
    var searchQuery by remember { mutableStateOf("") }
    
    Column {
        SearchBar(
            query = searchQuery,
            onQueryChange = { searchQuery = it }
        )
        SearchResults(query = searchQuery)
    }
}

@Composable
fun SearchBar(
    query: String,
    onQueryChange: (String) -> Unit
) {
    TextField(
        value = query,
        onValueChange = onQueryChange
    )
}

ViewModel Integration

For complex state, use ViewModels:

class SearchViewModel : ViewModel() {
    private val _searchState = MutableStateFlow(SearchState())
    val searchState = _searchState.asStateFlow()
    
    fun onSearchQueryChanged(query: String) {
        _searchState.update { it.copy(query = query) }
        performSearch(query)
    }
}

@Composable
fun SearchScreen(viewModel: SearchViewModel = hiltViewModel()) {
    val state by viewModel.searchState.collectAsState()
    
    SearchContent(
        state = state,
        onQueryChange = viewModel::onSearchQueryChanged
    )
}

Remember vs RememberSaveable

• Use remember for temporary state
• Use rememberSaveable for state that survives configuration changes

Conclusion

Proper state management makes your Compose UI predictable and performant. Start simple and add complexity only when needed.