prism_state_views

One widget for empty, loading, error, and success states in Flutter — with retry callbacks, Dart 3 sealed view-state classes, and compiler-checked exhaustiveness. Pure Flutter, all six platforms.

Features

• ✅ PrismStateView renders all four async UI states from one widget
• ✅ Dart 3 sealed class PrismViewState<T> — the compiler forces you to handle every state, no forgotten error branches
• ✅ Built-in "Retry" button on errors (opt-in via onRetry)
• ✅ Empty-state action button
• ✅ PrismViewStateNotifier.fromFuture for apps without state management
• ✅ Animated cross-fade between states
• ✅ All six Flutter platforms: Android, iOS, macOS, Windows, Linux, Web

Installation

dependencies:
  prism_state_views: ^0.1.0

Usage

PrismStateView<List<Item>>(
  state: state, // PrismViewState<List<Item>>
  onRetry: () => refetch(),
  emptyMessage: 'No items yet',
  emptyActionLabel: 'Add item',
  onEmptyAction: () => openEditor(),
  successBuilder: (items) => ListView.builder(
    itemCount: items.length,
    itemBuilder: (context, i) => ListTile(title: Text(items[i].name)),
  ),
)

Exhaustive switching (the Dart 3 way)

final widget = switch (state) {
  PrismViewLoading(:final message) => Text(message ?? 'Loading…'),
  PrismViewError(:final error) => Text('Failed: $error'),
  PrismViewEmpty() => const Text('Nothing here'),
  PrismViewSuccess(:final data) => Text(data.first.name),
};

Add a new state to the sealed class and every switch in your codebase stops compiling until it's handled — that's the whole point.

Without a state-management package

final state = PrismViewStateNotifier.fromFuture(loadItems());
// Use with ValueListenableBuilder, or pass .value to PrismStateView.

License

MIT — see LICENSE.