如何用HttpInterceptor拦截角度4的响应

Question

我有以下拦截器:

@Injectable()
export class TokenInterceptor implements HttpInterceptor {

  constructor(private tokenService: TokenService) { }

  intercept(req: HttpRequest<any>, next: HttpHandler): Observable<HttpEvent<any>> {
    const token = this.tokenService.getToken();

    if (token) {
      const authReq = req.clone({
        headers: req.headers.set('Authorization', `Bearer ${token}`)
      });

      return next.handle(authReq);
    }

    return next
      .handle(req)
//
      .getSomehowTheResponse()
      .andSaveTheTokenInStorage()
      .andPropagateNextTheResponse()
  }
}

我想从本地存储中的响应头保存令牌,所有教程都显示如何拦截请求,但不是很清楚响应.

Answer 1

next.handle(req) 返回一个observable,以便您可以订阅它:

return next.handle(req).map((event: HttpEvent<any>) => {
  if (event instanceof HttpResponse) {
    // do stuff with response and headers you want
    event.headers
    event.body
  }
  return event;
})

要了解有关拦截器背后的力学的更多信息,请阅读:

• Insider的Angular中的拦截器和HttpClient机制指南