df_di 0.1.0

A powerful and versatile dependency injection (DI) system with service classes for easy state management.

example/example.dart

//.title
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//
// Dart/Flutter (DF) Packages by DevCetra.com & contributors. The use of this
// source code is governed by an MIT-style license described in the LICENSE
// file located in this project's root directory.
//
// See: https://opensource.org/license/mit
//
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//.title~

// ignore_for_file: invalid_use_of_protected_member

import 'dart:async';

import 'package:df_di/df_di.dart';
import 'package:flutter/foundation.dart';

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void main() async {
  if (kDebugMode) {
    // Print the current state of di to understand what's registed.
    print(di.registry.state); // Nothing registered at this point.

    // Register FooBarService as a lazy singleton.
    di.registerSingletonService(FooBarService.new);
    // Now we have a SingletonInst<FooBarService> registered.
    print(di.registry.state);

    final fooBarService1 = await di.get<FooBarService>();

    // SingletonInst<FooBarService> is gone, now we have a FooBarService registered.
    print(di.registry.state);

    final fooBarService2 = di<FooBarService>();
    final fooBarService3 = di<FooBarService>();

    // Same instances, prints true.
    print(fooBarService1 == fooBarService2);
    print(fooBarService2 == fooBarService3);

    di.registerSingletonService(SyncServiceExmple.new);
    print(di.get<SyncServiceExmple>() is Future); // false
    // Use getSync/getSyncOrNull if you expect a sync.
    print(di.getSync<SyncServiceExmple>());

    di.registerSingletonService(AsyncServiceExample.new);
    print(di.registry.state);

    // Use getAsync/getAsyncOrNull if you expect an async.
    print(di.getAsync<AsyncServiceExample>());
    print(di.registry.state);

    di.registerSingletonService(CountingService.new);
    final coutingService = di.get<CountingService>();
    print(coutingService);

    Future.delayed(
      const Duration(seconds: 5),
      () async {
        di.unregisterAll(
          (e) {
            if (kDebugMode) {
              print(e);
            }
          },
        ).thenOr((_) {
          if (kDebugMode) {
            print('Disposed all!');
          }
        });
      },
    );
  }
}

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/// A new service class that extends [Service].
///
/// - Register via `di.initSingletonService(FooBarService.new);`
/// - Get via `di.get<FooBarService>();`
/// - Unregister via `di.unregister<FooBarService>();`
final class FooBarService extends Service {
  /// Gets [_vFooBar] as a [ValueListenable] to discourage tampering with [ValueNotifier].
  ValueListenable<String?> get vFooBar => _vFooBar;
  final _vFooBar = ValueNotifier<String?>(null);

  @override
  FutureOr<void> onInitService() async {
    _vFooBar.value = 'FooBar';
  }

  @override
  FutureOr<void> onDispose() {
    if (kDebugMode) {
      print('Disposed $CountingService');
    }
    _vFooBar.dispose();
  }
}

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final class CountingService extends StreamingService<int> {
  @override
  Stream<int> provideInputStream() async* {
    for (var n = 0; n < 100; n++) {
      await Future<void>.delayed(const Duration(seconds: 1));
      yield n;
    }
  }

  @override
  void onPushToStream(int data) {
    if (kDebugMode) {
      print('[CountingService]: $data');
    }
  }

  @override
  FutureOr<void> onDispose() {
    if (kDebugMode) {
      print('Disposed $CountingService');
    }
    return super.onDispose();
  }
}

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// An example of a service that DI will treat as sync.
final class SyncServiceExmple extends Service {
  @override
  void onInitService() {}

  @override
  void onDispose() {}
}

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// An example of a service that DI will treat as async.
final class AsyncServiceExample extends Service {
  @override
  Future<void> onInitService() async {
    await Future<void>.delayed(
      const Duration(seconds: 3),
    );
  }

  @override
  Future<void> onDispose() async {}
}