Question

我在后端中使用Nest JS。我有日志记录服务scoped.Request

@Injectable({ scope: Scope.REQUEST })
export class LoggingService extends BaseLoggerService implements LoggerService {
  constructor(readonly configService: ConfigurationService, @Inject(RequestContextService) readonly requestContextService: IRequestContextService) {}

我有需要记录服务的全局拦截器。

@Injectable()
export class LoggingInterceptor implements NestInterceptor {
    constructor(@Inject(LoggingService) private readonly logger: LoggingService) {
    }  }

现在在app.ts中，我试图绕过useGlobalInterceptors的实例来定义Logging service。但是，它在npm run start上引发错误。

app.useGlobalInterceptors(new LoggingInterceptor(app.get(LoggingService)));

错误

2020-02-20T10:51:54.409Z ERROR [object Object] (RID:NOT_SET RP:NOT_SET TK:) (AN:NOT_SET COM:NOT_SET UAN:NOT_SET) LoggingService is marked as a scoped provider. Request and transient-scoped providers can't be used in combination with "get()" method. Please, use "resolve()" instead. Error: LoggingService is marked as a scoped provider. Request and transient-scoped providers can't be used in combination with "get()" method. Please, use "resolve()" instead.

Answer 1

由于错误状态，LoggerService的作用域为REQUEST，因此您需要使用await app.resolve<LoggingService>(LoggingService)，但是，您可能想做的是在全局范围内绑定拦截器，然后让Nest通过将拦截器添加到providers数组中来处理依赖项注入：

@Module({
  imports: [...],
  providers: [
    {
      provide: APP_INTERCEPTOR,
      useClass: LoggingInterceptor
    },
    ...
  ]
})
export class AppModule {}

要记住的一点是，拦截器已经具有可用的整个请求上下文。另外，我不确定增强器在成为REQUEST范围的情况下如何工作（如果它具有REQUEST范围的依赖项，将会发生这种情况），因此请记住，这可能不是最佳的前进途径。

如何将请求范围服务的实例传递给全局拦截器

1 个答案: