@angular/core

Injectable

decorator

Decorator that marks a class as available to be provided and injected as a dependency.

API

@Injectable();
@Injectable(
  options?: {
    providedIn: Type<any> | 'root' | 'platform' | 'any' | null;
  } & InjectableProvider,
);

Usage Notes

Marking a class with @Injectable ensures that the compiler will generate the necessary metadata to create the class's dependencies when the class is injected.

The following example shows how a service class is properly marked so that a supporting service can be injected upon creation.

@Injectable()        class UsefulService {}        @Injectable()        class NeedsService {          constructor(public service: UsefulService) {}        }        const injector = Injector.create({          providers: [            {provide: NeedsService, deps: [UsefulService]},            {provide: UsefulService, deps: []},          ],        });        expect(injector.get(NeedsService).service instanceof UsefulService).toBe(true);