Need to display server down error


#1

I need to show server down error or Server busy error when Server is stopped. how to popup error

return this._http.post(this._queryUrlAuth, body, options)
      .map((res: Response) => res.json())
      .catch(this._errorHandler);

I am implementing the auth service here

getActivityQuery(): any {
    this._authServiec.getAuth().subscribe(data => {
      var token = JSON.parse(JSON.stringify(data));

      this._searchSubActivity.getSearchActivites(token, this.SearchStr).subscribe(data => {
        this._subActivityList = data.json();
      })
    });