async_lite #

Lightweight asynchronous utilities for Dart applications.

✨ Features #

• Result Type - Type-safe error handling with ValueResult and ErrorResult
• UI State - Convert Result to UI states (LoadingUiState, ValueUiState, ErrorUiState)
• LazyFutureExt - Automatic caching for concurrent async calls
• AsyncCache - Flexible caching with customizable TTL
• Minimal Dependencies - Lightweight and performant

🚀 Why async_lite? #

• Prevent Duplicate Calls - Multiple simultaneous calls to the same async function return the same result
• Type Safety - Explicit error handling without try-catch blocks
• Zero Boilerplate - Simple API that just works
• Production Ready - Battle-tested in real applications

💡 Usage #

LazyFutureExt - Prevent Duplicate API Calls #

import 'package:async_lite/async_lite.dart';

// Multiple calls return the same result
for (var i = 0; i < 5; i++) {
  fetchData.byLazy().then((result) => print(result));
}
// Only one actual call is made!

Future<String> fetchData() async {
  await Future.delayed(Duration(seconds: 2));
  return 'Data loaded';
}

Result Type - Clean Error Handling #

Future<Result<User>> getUser(String id) async {
  try {
    final user = await api.fetchUser(id);
    return ValueResult(user);
  } catch (e) {
    return ErrorResult(e.toString());
  }
}

// Usage
final result = await getUser('123');
switch (result) {
  case ValueResult(:final value):
    print('User: $value');
  case ErrorResult(:final error):
    print('Error: $error');
}

AsyncCache - Flexible Caching #

final cache = AsyncCache<Data>(Duration(minutes: 5));

// First call fetches data
final data1 = await cache.fetch(() => fetchExpensiveData());

// Subsequent calls return cached result
final data2 = await cache.fetch(() => fetchExpensiveData());

UI State - Simplify State Management #

import 'package:async_lite/src/ui_state.dart';

// Convert Result to UI State
final result = await fetchUser();
final state = result.toUiState();

// Handle different states
switch (state.type) {
  case UiState.loading:
    showLoader();
  case UiState.value:
    showData(state.valueOrNull);
  case UiState.error:
    showError(state.messageOrNull);
}

📖 Full Example #

See example/main.dart for complete usage examples.

📄 License #

MIT License - see LICENSE file for details.