bloc_signals_flutter 1.1.0

Flutter extensions and bindings for BlocSignal state management library.

⚡ bloc_signals_flutter "With the rigor of BLoC and the flex and speed of Signals" Flutter extensions, UI widgets, dependency injection providers, and reactive bindings for the bloc_signals state management library.

This companion package provides BlocSignalProvider, MultiBlocSignalProvider, BlocSignalBuilder, BlocSignalListener, BlocSignalConsumer, BlocSignalSelector, BuildContext extensions (read(), watch()), and Flutter Listenable interop helpers.

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🌐 Ecosystem Packages

The BlocSignal monorepo consists of 10 modular packages:

Package	Version	Description
bloc_signals		Core pure Dart reactive state primitives bridging BLoC & Signals
bloc_signals_flutter		Flutter UI bindings, providers, builders, listeners & selectors
bloc_signals_jaspr		Jaspr web component integration and state binding for BlocSignal
bloc_signals_riverpod		Bidirectional Riverpod 2/3 interop adapters & provider extensions
bloc_signals_hydrate		Automated synchronous local state persistence & hydration
bloc_signals_replay		Undo & redo state history tracking for CubitSignal and BlocSignal
bloc_signals_otel		OpenTelemetry tracing and span generation for state transitions
bloc_signals_devtools		Universal DevTools telemetry observer using dart:developer
bloc_signals_test		Declarative unit testing utilities (blocSignalTest)
bloc_signals_lint		Custom analyzer lint rules & automated IDE quick-fixes

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⚡ Key Features

• 📦 BlocSignalProvider: Dependency injection InheritedWidget with automatic container disposal on unmount.
• 🔗 MultiBlocSignalProvider: Nesting-free multi-bloc provider wrapper.
• ⚡ BlocSignalBuilder: Fine-grained reactive UI widget triggered synchronously on state changes.
• 👂 BlocSignalListener: Side-effect listener widget for snackbars, dialogs, and navigation.
• 🔀 BlocSignalConsumer: Combines builder and listener into a single widget.
• 🔍 BlocSignalSelector: Rebuilds ONLY when a derived state slice changes.

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🚀 Getting Started

Add bloc_signals_flutter to your pubspec.yaml:

dependencies:
  flutter:
    sdk: flutter
  bloc_signals_flutter: ^1.0.0

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💡 Quick Examples

1. Providing & Building (BlocSignalProvider & BlocSignalBuilder)

import 'package:flutter/material.dart';
import 'package:bloc_signals_flutter/bloc_signals_flutter.dart';

void main() {
  runApp(
    MaterialApp(
      home: BlocSignalProvider(
        create: (context) => CounterBloc(),
        child: const CounterScreen(),
      ),
    ),
  );
}

class CounterScreen extends StatelessWidget {
  const CounterScreen({super.key});

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(title: const Text('BlocSignal Counter')),
      body: Center(
        child: BlocSignalBuilder<CounterBloc, int>(
          builder: (context, state) => Text('Count: $state'),
        ),
      ),
      floatingActionButton: FloatingActionButton(
        onPressed: () => context.read<CounterBloc>().add(Increment()),
        child: const Icon(Icons.add),
      ),
    );
  }
}

2. Side-Effect Listener (BlocSignalListener)

BlocSignalListener<AuthBloc, AuthState>(
  listener: (context, state) {
    if (state is AuthFailure) {
      ScaffoldMessenger.of(context).showSnackBar(
        SnackBar(content: Text(state.error)),
      );
    }
  },
  child: const LoginForm(),
)

3. Combined Consumer (BlocSignalConsumer)

BlocSignalConsumer<CartBloc, CartState>(
  listener: (context, state) {
    if (state.itemAdded) {
      ScaffoldMessenger.of(context).showSnackBar(
        const SnackBar(content: Text('Item added to cart!')),
      );
    }
  },
  builder: (context, state) {
    return Text('Cart items: ${state.items.length}');
  },
)

4. Selective Rebuilds (BlocSignalSelector & context.select)

BlocSignalSelector<UserBloc, UserState, String>(
  selector: (state) => state.username, // Rebuilds ONLY if username changes
  options: ComputedOptions(name: 'UsernameSelector'), // Optional debug name
  builder: (context, username) {
    return Text('Hello, $username!');
  },
)

Or directly via BuildContext:

final canSubmit = context.select<FormCubit, bool>(
  (cubit) => cubit.stateValue.canSubmit,
);

Tip

Generic Type Parameters for context.select: Unlike Riverpod's 3-parameter context.select or package:flutter_bloc, BlocSignal's context.select takes 2 generic type parameters:

1. B: The BlocSignalBase container type (e.g., UserCubit or CounterBloc)
2. R: The selected return value type (e.g., String or bool)

The callback receives the bloc instance directly: context.select<FormCubit, bool>((cubit) => cubit.stateValue.canSubmit).

5. MultiBlocSignalProvider

MultiBlocSignalProvider(
  providers: [
    BlocSignalProvider<AuthBloc>(create: (context) => AuthBloc()),
    BlocSignalProvider<ThemeBloc>(create: (context) => ThemeBloc()),
  ],
  child: const AppShell(),
)

6. Flutter Listenable & ChangeNotifier Interop

// Convert any ChangeNotifier into a CubitSignal
final ChangeNotifier notifier = MyChangeNotifier();
final cubit = notifier.toBlocSignal(initialState: 0);

// Convert any CubitSignal into a Flutter ValueListenable
final ValueListenable<int> listenable = cubit.toValueListenable();

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🤖 AI Coding Assistant Skill & Guides

This package is supported by official pre-packaged AI Coding Skills and architectural documentation guides representing Flutter widget lifecycle patterns, UI binding rules, and migration paths for BlocSignal:

• 🔄 Migration Guide: Transitioning from classic package:flutter_bloc / package:bloc to BlocSignal.
• 🌁 Universal Interoperability Guide: Bridging state containers across BLoC, Riverpod, Provider, and Listenable primitives.
• 📦 AI Skill Bundle: Load the pre-packaged bloc-signals skill bundle for AI coding assistants (such as Claude Code, Antigravity, Gemini, Cursor, or Codex) to guide code generation and analysis.

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📜 Credits & Acknowledgements

Inspired by flutter_bloc by Felix Angelov and signals_flutter by Rody Davis.