MiruResourceView

Composable that eliminates repetitive when (resource) boilerplate by declaratively rendering loading, error, and success states.

Module: :ui-components

Definition

@Composable
fun <T> MiruResourceView(
    resource: Resource<T>,
    modifier: Modifier = Modifier,
    loadingMessage: String? = null,
    onRetry: (() -> Unit)? = null,
    onLoading: (@Composable () -> Unit)? = null,
    onError: (@Composable (String) -> Unit)? = null,
    content: @Composable (T) -> Unit
)

Parameters

Parameter	Type	Default	Description
resource	Resource<T>	required	The resource state to render
modifier	Modifier	Modifier	Applied to the root container
loadingMessage	String?	null	Message displayed in the default loading view
onRetry	(() -> Unit)?	null	Retry callback shown in the default error view
onLoading	@Composable?	null	Custom loading composable (overrides default)
onError	@Composable (String)?	null	Custom error composable (overrides default)
content	@Composable (T)	required	Content rendered when resource is Success

Default Behavior

State	Default Rendering
Resource.Loading	MiruFullScreenLoading(message = loadingMessage)
Resource.Error	MiruErrorView(message = ..., onRetry = onRetry)
Resource.Success	Calls content(data)

Basic Usage

@Composable
fun UserListScreen(viewModel: UserListViewModel = koinViewModel()) {
    val usersResource by viewModel.users.collectAsStateWithLifecycle()

    MiruResourceView(
        resource = usersResource,
        loadingMessage = "Loading users...",
        onRetry = { viewModel.loadUsers() }
    ) { users ->
        LazyColumn {
            items(users, key = { it.id }) { user ->
                UserCard(user)
            }
        }
    }
}

Custom Loading & Error

MiruResourceView(
    resource = feedResource,
    onRetry = { viewModel.refresh() },
    onLoading = {
        // Custom shimmer placeholder
        Column {
            repeat(5) { ShimmerCard() }
        }
    },
    onError = { message ->
        // Custom error banner
        Column(horizontalAlignment = Alignment.CenterHorizontally) {
            Icon(Icons.Default.Warning, contentDescription = null)
            Text(message)
            MiruButton(text = "Try Again", onClick = { viewModel.refresh() })
        }
    }
) { data ->
    FeedContent(data)
}

Data Source Agnostic

MiruResourceView works with any StateFlow<Resource<T>>, regardless of which BaseViewModel helper populated it:

// collectResource — suspend one-shot
fun load() = collectResource(_data) { useCase() }

// collectFlow — plain Flow<T>
fun observe() = collectFlow(_data) { dao.getAll() }

// collectFlowResource — Flow<Resource<T>>
fun stream() = collectFlowResource(_data) { useCase.observe() }

All three produce a StateFlow<Resource<T>> that you collect and pass to MiruResourceView:

val dataResource by viewModel.data.collectAsStateWithLifecycle()
MiruResourceView(resource = dataResource) { data -> /* render */ }

Before vs After

Before (manual handling):

val resource by viewModel.users.collectAsStateWithLifecycle()

when (resource) {
    is Resource.Loading -> MiruFullScreenLoading()
    is Resource.Error -> MiruErrorView(
        message = (resource as Resource.Error).exception.message ?: "Error",
        onRetry = { viewModel.loadUsers() }
    )
    is Resource.Success -> {
        val users = (resource as Resource.Success).data
        LazyColumn {
            items(users) { UserCard(it) }
        }
    }
}

After (with MiruResourceView):

val resource by viewModel.users.collectAsStateWithLifecycle()

MiruResourceView(
    resource = resource,
    onRetry = { viewModel.loadUsers() }
) { users ->
    LazyColumn {
        items(users) { UserCard(it) }
    }
}