ioc_locator 1.0.0

ioc_locator: ^1.0.0 copied to clipboard

example/ioc_locator_example.dart

import 'package:ioc_locator/ioc_locator.dart';

abstract class GreetingRepository {
  String greetingFor(String name);
}

class EnglishGreetingRepository implements GreetingRepository {
  @override
  String greetingFor(String name) => 'Hello, $name!';
}

class GreetingService {
  GreetingService(this.repository);

  final GreetingRepository repository;

  void greet(String name) => print(repository.greetingFor(name));
}

/// A service that needs asynchronous initialization — think: opening a
/// database, reading a settings file, establishing a connection.
class GreetingLog {
  GreetingLog._();

  static Future<GreetingLog> open() async {
    await Future<void>.delayed(const Duration(milliseconds: 10)); // e.g. file I/O
    return GreetingLog._();
  }

  final List<String> _entries = [];

  void add(String name) => _entries.add(name);

  Future<void> close() async {
    print('greeted ${_entries.length} time(s): ${_entries.join(', ')}');
  }
}

final ioc = IocLocator();

Future<void> main() async {
  // Register a lazily created singleton for the repository interface, a
  // factory for the service that depends on it, and an async singleton —
  // its factory starts running right here, at registration.
  ioc
    ..registerSingleton<GreetingRepository>(
      (locator) => EnglishGreetingRepository(),
    )
    ..register<GreetingService>(
      (locator) => GreetingService(locator.get<GreetingRepository>()),
    )
    ..registerSingletonAsync<GreetingLog>(
      (locator) => GreetingLog.open(),
      disposeAsync: (log) => log.close(),
    );

  // One await after registration. From here on every service — the async one
  // included — resolves with the plain synchronous get. (Without this await,
  // a too-early get<GreetingLog>() would throw IocServiceNotReady.)
  await ioc.allReady();

  final service = ioc.get<GreetingService>();
  service.greet('world');
  ioc.get<GreetingLog>().add('world');

  // Tear down everything created by the locator, in reverse creation order;
  // async disposers are awaited — close() has printed before this returns.
  await ioc.dispose();
}