// update operations upon selection
selectionModel.addSelectionChangeHandler(new SelectionChangeEvent.Handler() {
@Override
public void onSelectionChange(final SelectionChangeEvent event) {
code.clear();
AuditLogItem item = selectionModel.getSelectedObject();
JSONArray jsonArray = JSONParser.parseStrict(item.getOperations().getPayload()).isArray();
if (jsonArray != null) {
String stringify = stringify(jsonArray.getJavaScriptObject());
code.setValue(SafeHtmlUtils.fromString(stringify));