@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);