protected ServerMessage renderUpdate(Connection conn, Document clientMessageDocument) {
ServerMessage serverMessage = new ServerMessage();
RenderContext rc = new RenderContextImpl(conn, serverMessage);
ContainerInstance ci = rc.getContainerInstance();
ApplicationInstance applicationInstance = ci.getApplicationInstance();
try {
if (!validateTransactionId(ci, clientMessageDocument)) {
processInvalidTransaction(rc);
return serverMessage;
}
// Mark instance as active.
ApplicationInstance.setActive(applicationInstance);
UpdateManager updateManager = applicationInstance.getUpdateManager();
processClientFocusedComponent(rc, clientMessageDocument);
// Process updates from client.
processClientMessage(conn, clientMessageDocument);