Consuming #Coroutines #Flows safely in #JetpackCompose 📚.

ConsumingFlowsSafelyInJetpackCompose.kt

// CONSUMING FLOWS SAFELY IN JETPACK COMPOSE

import androidx.compose.runtime.*
import androidx.compose.ui.Modifier
import androidx.compose.ui.platform.LocalLifecycleOwner
import androidx.hilt.navigation.compose.hiltViewModel
import androidx.lifecycle.*
import androidx.lifecycle.compose.*
import androidx.lifecycle.repeatOnLifecycle
import kotlinx.collections.immutable.*
import kotlinx.coroutines.channels.*
import kotlinx.coroutines.flow.*

@Suppress("ComposableNaming")
@Composable
fun <T> Flow<T>.collectInLaunchedEffectWithLifecycle(
  vararg keys: Any?,
  lifecycle: Lifecycle = LocalLifecycleOwner.current.lifecycle,
  minActiveState: Lifecycle.State = Lifecycle.State.STARTED,
  collector: suspend (T) -> Unit
) {
  val flow = this
  LaunchedEffect(flow, lifecycle, minActiveState, *keys) {
    lifecycle.repeatOnLifecycle(minActiveState) { flow.collect(collector) }
  }
}

@Immutable data class User(val name: String, val age: Int)
@Immutable data class UsersUiState(
  val users: ImmutableList<User> = persistentListOf(),
  val isLoading: Boolean = true,
  val error: Throwable? = null
)

sealed class UsersSingleEvent {
  data class Failure(val error: Throwable) : UsersSingleEvent()
  object Success : UsersSingleEvent()
}

@HiltViewModel class UsersViewModel @Inject constructor() : ViewModel() {
  private val _eventChannel = Channel<UsersSingleEvent>(Channel.UNLIMITED)

  val uiStateFlow: StateFlow<UsersUiState> = TODO()
  val eventFlow: Flow<UsersSingleEvent> get() = _eventChannel.receiveAsFlow()
}

@OptIn(ExperimentalLifecycleComposeApi::class)
@Composable fun UsersScreen(
  modifier: Modifier = Modifier,
  viewModel: UsersViewModel = hiltViewModel()
) {
  viewModel.eventFlow.collectInLaunchedEffectWithLifecycle { event ->
    when (event) {
      is UsersSingleEvent.Failure -> TODO()
      UsersSingleEvent.Success -> TODO()
    }
  }

  // Use "androidx.lifecycle:lifecycle-runtime-compose:2.6.0-alpha03"
  val uiState = viewModel.uiStateFlow.collectAsStateWithLifecycle()
  // Use uiState ...
}