android-compose-state-effects

Android Compose State Effects

When To Use

• Use this skill when the request is about: compose side effect problem, remember vs derivedstateof, collect flow in compose screen.
• Primary outcome: Manage Compose state, remember APIs, side effects, snapshots, and lifecycle-aware collection without leaks or loops.
• Reach for this skill when the problem lives inside a composable or Compose runtime primitive, not when redesigning app-wide state holders or reducers.
• This skill is about runtime primitives inside Compose. If the question is reducer design, screen contracts, or ViewModel ownership, hand off to android-state-management.
• Handoff skills when the scope expands:
• android-state-management
• android-compose-performance

Workflow

1. Classify the issue first: local remembered state, saved state, derived state, lifecycle-aware collection, or one-off side effects.
2. Pick the narrowest Compose primitive that matches that problem: remember, rememberSaveable, derivedStateOf, produceState, collectAsStateWithLifecycle, LaunchedEffect, DisposableEffect, SideEffect, or snapshotFlow.
3. Keep durable UI state separate from transient events such as snackbars, navigation, and analytics.
4. Stabilize effect keys and callback references so recomposition does not relaunch work or capture stale lambdas.
5. Hand off broader state-holder design to android-state-management only after the Compose-runtime issue is isolated.

Guardrails

• Prefer lifecycle-aware collection such as collectAsStateWithLifecycle for UI-facing flows.
• Use rememberUpdatedState when an effect should see the latest lambda or value without restarting.
• Keep one-shot effects out of immutable screen state when they are really events.
• Do not launch coroutines or trigger navigation directly from the composable body outside the appropriate effect APIs.

Anti-Patterns

• Using LaunchedEffect(Unit) or unstable keys when the effect should restart on real dependency changes.
• Collecting flows in multiple places and wondering why events duplicate.
• Storing transient events as persistent booleans in screen state and then manually resetting them.
• Using derivedStateOf or snapshotFlow when plain state reads would be simpler and cheaper.