ABUS - A-synchronous Business Unified System #

A unified Flutter package for handling asynchronous operations with built-in optimistic updates, automatic rollback, and seamlessly integrated feedback and storage capabilities.

Key Features #

• 🚀 Optimistic Updates - Instant UI responses with automatic rollback on failure
• 💬 Core Feedback System - Built-in, persistent managed feedback queue (Toasts, Snobars, Banners)
• 💾 Cross-App Communication - Synchronize state and events across apps using shared storage
• 🔄 Universal Integration - Works with BLoC, Provider, setState, or any state management
• 🛡️ Race Condition Prevention - Intelligent operation queuing
• 🎯 Type-Safe Operations - Define operations once, use everywhere
• 🔧 Zero Boilerplate - Minimal setup, maximum functionality

Quick Start #

Installation #

dependencies:
  abus: ^0.0.7

1. Unified Setup #

Initialize ABUS with the integrated Storage and Feedback systems for the full experience.

void main() async {
  // 1. Configure shared storage (optional but recommended for persistence/cross-app)
  final storage = AndroidSharedStorage(
    Directory('/sdcard/Android/data/com.example/files'),
    syncInterval: Duration(seconds: 5),
  );

  // 2. Initialize ABUS components
  ABUS.setStorage(storage);
  await FeedbackBus.initialize(storage: storage);

  runApp(MyApp());
}

2. Core Usage Flow #

Execute operations that update the UI instantly and automatically handle feedback.

// Define an operation
final interaction = InteractionTypes.crud(
  action: 'create',
  resourceType: 'user',
  payload: {'name': 'John'},
);

// Execute: Optimistic update -> API Call -> Feedback
final result = await ABUS.execute(interaction);

if (result.isSuccess) {
  // Show persistent feedback automatically managed by the system
  FeedbackBus.showSnackbar(
    message: 'User created successfully',
    type: SnackbarType.success,
    actionLabel: 'UNDO',
    onAction: () => undoCreate(),
  );
}

3. Widget Integration #

React to both data changes and feedback events in one place using AbusWidgetMixin and FeedbackWidgetMixin.

class UserScreen extends StatefulWidget {
  const UserScreen({super.key});

  @override
  State<UserScreen> createState() => _UserScreenState();
}

class _UserScreenState extends State<UserScreen> with AbusWidgetMixin, FeedbackWidgetMixin {
  
  @override
  Widget build(BuildContext context) {
    return Scaffold(
      body: Stack(
        children: [
          // Your main content
          ListView(children: [/*...*/]),
          
          // Render persistent banners from the feedback queue
          Column(
             children: bannerEvents.map((e) => MaterialBanner(/*...*/)).toList(),
          ),
        ],
      ),
    );
  }

  @override
  void onFeedbackQueueChanged(List<FeedbackEvent> queue) {
    // Check for new snackbars in the queue
    final latest = snackbarEvents.lastOrNull;
    if (latest != null && !isShown(latest.id)) {
      ScaffoldMessenger.of(context).showSnackBar(/*...*/);
      markAsShown(latest.id);
    }
  }
}

Deep Integration #

State Management (BLoC Example) #

ABUS handlers integrate deeply with your state management to handle optimistic updates and rollbacks.

class UserBloc extends Bloc<UserEvent, UserState> with AbusBloc<UserState> {
  // ... configuration ...

  @override
  Future<void> handleOptimistic(String id, InteractionDefinition interaction) async {
    // 1. Update state immediately
    emit(state.copyWith(loading: true, tempUser: interaction.payload));
  }

  @override
  Future<ABUSResult> executeAPI(InteractionDefinition interaction) async {
    try {
      // 2. Perform actual API call
      return await api.createUser(interaction.payload);
    } catch (e) {
      // 3. System automatically triggers handleRollback on failure
      return ABUSResult.error(e.toString());
    }
  }
}

Storage & Cross-App Sync #

Enable powerful multi-app workflows where events in one app (e.g., a background service) are instantly reflected in another.

// App A (Background Service)
await FeedbackBus.showBanner(
  message: 'Background Sync Complete',
  priority: 10
);

// App B (Foreground UI)
// Automatically receives the banner event via AndroidSharedStorage 
// and updates the UI through FeedbackWidgetMixin.

Read full documentation on Cross-App Communication

Documentation #

• 📖 Full Documentation
  • Feedback System Details
  • Storage Internals
• 🎯 API Reference
• 💡 Example App

License #

This project is licensed under the MIT License - see the LICENSE file for details.