Nest: Question: Inject class by identifier for interfaces

Created on 5 May 2017 · 3Comments · Source: nestjs/nest

Hi,

is it possible to configure the dependency injector that I can map a typescript interface to a specific class?

Example:

@Controller('registration')
export class RegistrationController {

  private readonly registrationService: RegistrationService;

  constructor(registrationService: IRegistrationService) {
    this.registrationService = registrationService;
  }

export interface IRegistrationService {
  register(): void;
}

export class RegistrationService implements IRegistrationService {
  public register(): void {
    // ...
 }
}

How can I tell my module that for the IRegistrationService I'd like to inject the RegistrationService class?

In AngularJS I could use a string as identifier and use an @Inject decorator on the constructor parameter of the controller class

Example:

@ngModule({
  providers: [
    {provide: 'RegistrationService', useClass: RegistrationService},
  ],
})
export class RegistrationModule {
}

@Controller('registration')
export class RegistrationController {

  private readonly registrationService: RegistrationService;

  constructor(@Inject('RegistrationService') registrationService: IRegistrationService) {
    this.registrationService = registrationService;
  }

Is this possible?

Source