depend 3.0.0

depend simplifies dependency management in Flutter apps, providing easy initialization and access to services across the widget tree.

depend

depend is a library for managing dependencies in Flutter applications. It provides a convenient way to initialize and access services or repositories via an InheritedWidget.

---

Why it Rocks 🚀

• Initialize dependencies before launching the app
• Access dependencies from anywhere in the widget tree
• Clean and extensible way to manage dependencies
• Easy to use and integrate with existing codebases

---

• dependencies
  • Why it Rocks 🚀
  • Installation
  • Example Usage
    • Example 1: Define InjectionScope
      • Step 2: Initialize InjectionScope
      • Step 3: Access InjectionScope with InheritedWidget
    • Example 2: Use Parent InjectionScope
      • Step 1: Define Parent InjectionScope
  • Migrate v2 to v3

---

Installation

Add the package to your pubspec.yaml:

dependencies:
  depend: ^latest_version

Then run:

$ flutter pub get

---

Example Usage

Example 1: Define InjectionScope

Step 1: Extends Injection

Create a Injection that extends Injection and initializes your dependencies:

class RootInjection extends Injection {
  late final ApiService apiService;

  @override
  Future<void> init() async {
    apiService = await ApiService().init()
  }
}

Step 2: Initialize InjectionScope

Use InjectionScope to initialize your dependencies before launching the app:

void main() {
  runApp(
    InjectionScope<RootInjection>(
      injection: RootInjection(),
      placeholder: const ColoredBox(
        color: Colors.white,
        child: Center(child: CircularProgressIndicator()),
      ),
      child: const MyApp(),
    ),
  );
}

Step 3: Access InjectionScope with InheritedWidget

Once initialized, dependencies can be accessed from anywhere in the widget tree using InjectionScope.of(context).authRepository:

/// The repository for the example
final class AuthRepository {
  final AuthDataSource dataSource;

  AuthRepository({required this.dataSource});

  Future<String> login() => dataSource.login();
  
  void dispose() {
    // stream.close();
  }
}

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

  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      title: 'Flutter Demo',
      home: InjectionScope<ModuleInjection>(
        injection: ModuleInjection(
          parent: InjectionScope.of<RootInjection>(context),
        ),
        child: BlocProvider(
          create: (context) => DefaultBloc(
            InjectionScope.of<ModuleInjection>(context).authRepository,
          ),
          child: const MyHomePage(),
        ),
      ),
    );
  }
}

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

  @override
  State<MyHomePage> createState() => _MyHomePageState();
}

class _MyHomePageState extends State<MyHomePage> {
  void _login() {
    context.read<DefaultBloc>().add(DefaultEvent());
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      body: SafeArea(
        child: SingleChildScrollView(
          child: Column(
            children: [
              BlocBuilder<DefaultBloc, DefaultState>(
                builder: (context, state) {
                  return Text('Login: ${state.authorized}');
                },
              ),
              Builder(
                builder: (context) {
                  return ElevatedButton(
                    onPressed: _login,
                    child: const Text('Login'),
                  );
                },
              )
            ],
          ),
        ),
      ),
    );
  }
}

Example 2: Use Parent InjectionScope

Step 1: Define Parent InjectionScope

class RootInjection extends Injection {
  late final ApiService apiService;

  @override
  Future<void> init() async {
    apiService = await ApiService().init();
  }
}

class ModuleInjection extends Injection<RootInjection> {
  late final AuthRepository authRepository;

  ModuleInjection({required super.parent});

  @override
  Future<void> init() async {
    // initialize dependencies
    authRepository = AuthRepository(
      dataSource: AuthDataSource(
        apiService: parent.apiService, // parent - RootInjection
      ),
    );
  }

  @override
  void dispose() {
    authRepository.dispose();
  }
}

Migrate from v2 to v3

In version 2, dependencies were injected using Dependencies, but in version 3, this has been replaced by InjectionScope. Here's how you would migrate:

v2:

void main() {
  runApp(
    Dependencies<RootLibrary>(
      library: RootLibrary(),
      placeholder: const ColoredBox(
        color: Colors.white,
        child: Center(child: CircularProgressIndicator()),
      ),
      child: const MyApp(),
    ),
  );
}

v3:

void main() {
  runApp(
    InjectionScope<RootInjection>(
      injection: RootInjection(),
      placeholder: const ColoredBox(
        color: Colors.white,
        child: Center(child: CircularProgressIndicator()),
      ),
      child: const MyApp(),
    ),
  );
}

The key change is moving from Dependencies to InjectionScope, reflecting the updated structure for managing and accessing dependencies.

---

v2:

class RootLibrary extends DependenciesLibrary {
  late final ApiService apiService;

  @override
  Future<void> init() async {
    apiService = await ApiService().init();
  }
}

v3:

class RootInjection extends Injection {
  late final ApiService apiService;

  @override
  Future<void> init() async {
    apiService = await ApiService().init();
  }
}

The primary change here is the renaming of RootLibrary to RootInjection, aligning with the shift in naming conventions from DependenciesLibrary in v2 to Injection in v3.

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