code: @Override
      public void onRequest(final AjaxRequestTarget _target)
      {
          final UICmdField uiObject = (UICmdField) getDefaultModelObject();
          final StringBuilder snip = new StringBuilder();
          try {
              final AbstractUIPageObject pageObject = (AbstractUIPageObject) getPage().getDefaultModelObject();
              final Map<String, String> uiID2Oid = pageObject == null ? null : pageObject.getUiID2Oid();
              final List<Return> returns = uiObject.executeEvents(null, uiID2Oid);
              for (final Return oneReturn : returns) {
                  if (oneReturn.contains(ReturnValues.SNIPLETT)) {
                      snip.append(oneReturn.get(ReturnValues.SNIPLETT));
                  }
              }
          } catch (final EFapsException e) {
              throw new RestartResponseException(new ErrorPage(e));
          }
          _target.appendJavaScript(snip.toString());
      }
docs: On submit.
  
  @param _target   AjaxRequestTarget