javascript - NestJS 在拦截器中设置 HttpStatus

Question

我正在使用拦截器来转换我的响应。我想设置HttpStatus在里面，但我现在使用的代码不起作用。

import { CallHandler, ExecutionContext, NestInterceptor, SetMetadata } from '@nestjs/common';
import { Observable } from 'rxjs';
import { map } from 'rxjs/operators';
import { classToPlain } from 'class-transformer';
import { ApiResponse } from '../models/apiResponse';

export class TransformInterceptor implements NestInterceptor {
  intercept(
    context: ExecutionContext,
    next: CallHandler<ApiResponse | any>,
  ): Observable<ApiResponse | any> {
    return next.handle().pipe(
      map(data => {
        const http = context.switchToHttp();
        const res = http.getResponse();

        if(data instanceof ApiResponse) {
          if(data.status !== undefined) {
            res.status(data.status);
          }
        }

        return classToPlain(data);
      }),
    );
  }
}

Answer 1

更新的答案

从 Nest 版本 6.1.0 开始，可以在拦截器中设置状态码；它不会再被覆盖(见 this PR ):

context.switchToHttp()
      .getResponse()
      .status(205);

过时的答案

从拦截器设置状态码是不可能的(见 issue )，因为:

• sometimes response status codes are dependent on exceptions and exception filters are executed after interceptors,
• global response controller's logic is the last step performed just before sending a final result through the network (that's the place where default status codes come in).

因此，您的状态代码将被默认代码 200/201 或异常过滤器覆盖。



作为(hacky)解决方法，您可以使用异常过滤器在拦截器中设置状态代码:

1) 创建自己的异常作为 HttpException 的包装器:

export class StatusException extends HttpException {
  constructor(data, status: HttpStatus) {
    super(data, status);
  }
}

2)创建一个异常过滤器，设置响应码并返回数据:

@Catch(StatusException)
export class StatusFilter implements ExceptionFilter {
  catch(exception: StatusException, host: ArgumentsHost) {
    const ctx = host.switchToHttp();
    const response = ctx.getResponse<Response>();
    const status = exception.getStatus();
    console.log(`Setting status to ${status}`);
    response.status(status).json(exception.message);
  }
}

3)而不是设置响应在你的拦截器中抛出相应的异常:

@Injectable()
export class StatusInterceptor implements NestInterceptor {
  intercept(context: ExecutionContext, next): Observable<any> {
    return next.handle().pipe(
      map((data: any) => {
        if (data.text === 'created') {
          throw new StatusException(data, HttpStatus.CREATED);
        } else {
          throw new StatusException(data, HttpStatus.ACCEPTED);
        }
      }),
    );
  }
}

4)在您的 Controller 中使用它:

@UseFilters(StatusFilter)
@UseInterceptors(StatusInterceptor)
@Controller()
export class AppController {
  @Get(':param')
  async get(@Param('param') param) {
    return { text: param };
  }
}

或者，您可以注入(inject) @Res()在您的 Controller 中并直接控制响应代码(但也会丢失拦截器、异常过滤器等)