# Java Client Customizing

## Widget handling

| The client only gets layout and data changes for the current widget (the widget a userexit was executed in). If server side code modifies an already opened widget that is not in the scope of the current call, the client has to be informed by calling dal_wdg_rfr_cli. Adding or removing fields from a mask should be done in the pre-mask trigger. If done later, the server does not inform the client. Hiding or unhiding a field however works fine.