Angular 12 References/ Core
🍀 Angular References

@Self

A constructor parameter decorator that tells the DI framework to retrieve a dependency only from the local injector.

constructor(@Self() service: Service) {}

Example

In the following example, the dependency can be resolved by the local injector when instantiating the class itself, but not when instantiating a child.

class Dependency {}
 
@Injectable()
class NeedsDependency {
  constructor(@Self() public dependency: Dependency) {}
}
 
let inj = ReflectiveInjector.resolveAndCreate([Dependency, NeedsDependency]);
const nd = inj.get(NeedsDependency);
 
expect(nd.dependency instanceof Dependency).toBe(true);
 
inj = ReflectiveInjector.resolveAndCreate([Dependency]);
const child = inj.resolveAndCreateChild([NeedsDependency]);
expect(() => child.get(NeedsDependency)).toThrowError();