This is a simple example; in production you may prefer to use the:doc:`Translation</components/translation>`

component to manage messages in one place::

namespace App\Listener\Workflow\Task;

use Symfony\Component\EventDispatcher\EventSubscriberInterface;

use Symfony\Component\Workflow\Event\GuardEvent;

use Symfony\Component\Workflow\TransitionBlocker;

class OverdueGuard implements EventSubscriberInterface

{

public function guardPublish(GuardEvent $event)

$timeLimit = $event->getMetadata('time_limit', $event->getTransition());

if (date('Hi') <= $timeLimit) {

return;

}

$explanation = $event->getMetadata('explanation', $event->getTransition());

$event->addTransitionBlocker(new TransitionBlocker($explanation , 0));

}

public static function getSubscribedEvents()

{

return [

'workflow.task.guard.done' => 'guardPublish',

];

}

..versionadded::4.1