CallBackResponse not working all the times

[promi8eas]

What are you trying to accomplish? The browser window dimensions are already set in WebApplication.FormWidth and FormHeight.

If you want to keep track if it when browser resizes, set an OnAsyncResize event handler and the information will be updated every time the browser resizes.

Unfortunately, I have already tried this and for sure it doesn't work. FormWidth and FormHeight cannot return the correct dimensions when it runs from a mobile browser like Samsung Internet.  Anyway I found somewhere else the following solution:

procedure TIndex.IWAppFormCreate(Sender: TObject);
const
  jsTag = '<script language="javascript" type="text/javascript">%s</script>';
var
  AjaxFunc: string;
begin
  AjaxFunc := 'function myAjaxFunc() {' + #13 +
      'executeAjaxEvent("&data="+screen.width, null,"' + UpperCase(Self.Name) +
      '.DoMyAjaxFunc", false, null, true);' + #13 +
      'return true;}';
  PageContext.ExtraHeader.Add(Format(jsTag, [AjaxFunc]));
  WebApplication.RegisterCallBack(UpperCase(Self.Name) + '.DoMyAjaxFunc', DoMyAjaxFunc);
  cmdLogin.ScriptEvents.HookEvent('OnMouseOver', 'myAjaxFunc();');
end;

procedure TIndex.DoMyAjaxFunc(EventParams: TStringList);
var
  sl: TStrings;
  s: string;
begin
  sl := TStringList.Create;
  try
    sl.StrictDelimiter := True;
    sl.CommaText := EventParams.Values['data'];
    s := sl.CommaText;
  finally
    sl.Free;
  end;
  UserSession.MyBrowserWidth:=s2i(s);
end;