PostConstruct class

Marks a method to be invoked after a pod has been fully constructed and its dependencies injected, but before it is made available for use in the context.

This is typically used for:

• Initialization logic that depends on injected fields.
• Validating configuration.
• Opening resources (like database connections).

Rules

• Must be a no-arg method.
• Return type should be void or Future<void>.
• Only applied to methods (not classes or fields).

Example — Synchronous Initialization

@Service()
class CacheManager {
  late final Cache _cache;

  @Autowired()
  late final DataSource dataSource;

  @PostConstruct()
  void init() {
    print("Initializing cache from database...");
    _cache = Cache.loadFrom(dataSource);
  }
}

Example — Asynchronous Initialization

@Service()
class WorkerPool {
  final _workers = <Worker>[];

  @PostConstruct()
  Future<void> startWorkers() async {
    for (var i = 0; i < 4; i++) {
      final worker = Worker();
      await worker.start();
      _workers.add(worker);
    }
  }
}