Angular Http Interceptor：catchError 并返回成功

Question

我有一个捕获错误的 Http 拦截器（Angular 7）。是否有可能捕获错误并根据某些条件返回成功而不是错误？我当前的代码。

export class RequestInterceptor implements HttpInterceptor {

  constructor() {}

  intercept(request: HttpRequest<any>, next: HttpHandler): Observable<HttpEvent<any>> {

    return next.handle(request).pipe(
      catchError( response => {
        if(someCondition) {
           //return something that won't throw an error
        }
        return of(response)
      })
    )

  }
}

Answer 1

您需要返回一个Observable<HttpEvent<any>>对象。您可以通过使用发出另一个请求来实现这一点next.handle(newReq)

例如，如果您想在错误为 401 时添加 Bearer 授权标头，您可以这样做

intercept(request: HttpRequest<any>, next: HttpHandler): Observable<HttpEvent<any>> {

return next.handle(request).pipe(
  catchError( response => {
    if(response.status === 401) {
       return next.handle(request.clone({
         setHeaders: { "Authorization": `Bearer ${token}` }
       }));
    }
    return throwError(() => new Error(response));
  })
 )
}