chat with Symfony mercure Failed to send an update & Message does not added in the data base

Question

i want to create a real time chat group with symfony mercure, this is my MessageController code but i have this error when i ping mercure to do the update "Failed to send an update", also the message does not added in the database what is the problem!! Does anyone know what causes this issue and how to resolve it?

<?php

namespace App\Controller;

use App\Entity\GroupConversation;
use App\Entity\Message;
use App\Entity\User;
use App\Form\MessageType;
use App\Repository\MessageRepository;
use App\Repository\UserRepository;
use App\Service\CookieGenerator;
use Doctrine\ORM\EntityManagerInterface;
use Symfony\Bundle\FrameworkBundle\Controller\AbstractController;
use Symfony\Component\HttpFoundation\Request;
use Symfony\Component\HttpFoundation\Response;
use Symfony\Component\Routing\Annotation\Route;
use Symfony\Component\Mercure\HubInterface;
use Symfony\Component\Mercure\Update;
use Symfony\Component\Security\Core\Security;
use Symfony\Component\Uid\Uuid;


/**
 * @Route("/messages", name="messages_")
 */
class MessageController extends AbstractController
{

    /**
     * @var MessageRepository
     */
    private $messageRepository;
    /**
     * @var UserRepository
     */
    private UserRepository $userRepository;

    /**
     * @var EntityManagerInterface
     */
    private $em;

    /**
     * @var Security
     */
    private Security $security;

    public function __construct(MessageRepository $messageRepository,
                                UserRepository $userRepository,
                                EntityManagerInterface $em,
                                Security $security)
    {
        $this->messageRepository    = $messageRepository;
        $this->userRepository       = $userRepository;
        $this->em                   = $em;
        $this->security             = $security;
    }

    //BREAD controller action pattern

    /**
     * Display list of messages from conversation
     *
     * @Route("/{groupConversation}", name="browse")
     * @param GroupConversation $groupConversation
     * @return Response
     */
    public function browse(GroupConversation $groupConversation): Response {

        $this->denyAccessUnlessGranted('ROLE_USER');

        $messages = $this->messageRepository->findMessageByConversationId($groupConversation->getId());

        $response = $this->render('message/browse.html.twig', [
            'conversation' => $groupConversation,
            'messages' => $messages,
        ]);

        return $response;
    }

    /**
     * Create new message
     *
     * @Route("/{id}/add", name="add", requirements={"id" : "\d+"})
     */
    public function add(Request $request,
                        HubInterface $hub,
                        GroupConversation $groupConversation): Response
    {
        $this->denyAccessUnlessGranted('ROLE_USER');
        //used with connected user
        $user = $this->security->getUser();
        if(!($user)) {
            $this->addFlash('error', 'Utilisateur incorrect.');
            return $this->redirectToRoute('app_login');
        }

        $message = new Message();

        $form = $this->createForm(MessageType::class, $message);
        $form->handleRequest($request);
        $content = $request->get('message-box', null);

        if ($content) {

            $message->setCreated(new \DateTime('now'));
            $message->setUpdated(new \DateTime('now'));
            $message->setContent($content);
            $message->setMine(true);
            $message->setSeen(false);

            $message->setUser($user);
            $groupConversation->addMessage($message);

            try {
                $date   = new \DateTime('now');
                $update = new Update(
                    '/messages/' . $groupConversation->getId(), //IRI, the topic being updated, can be any string usually URL
                    json_encode([
                        'conversation'  => 'Nouveau message conversation :' . $groupConversation->getName(),
                        'message'       => $content,
                        'from'          => $user->getUsername(),
                        'to'            => $groupConversation->getUsers(),
                        'date'          => $date->format('H:i'),
                    ]), //the content of the update, can be anything
                    $groupConversation->getPrivate(), //private
                    'message-' . Uuid::v4(),//mercure id
                    'message'
                );

                //PUBLISHER JWT : doit contenir la liste des conversations dans lesquels il peut publier conf => mercure.publish
                //SUBSCRIBER JWT: doit contenir la liste des conversations dans lesquels il peut recevoir conf => mercure.subcribe

                $hub->publish($update);
                $this->em->flush();
            }
            catch (\Exception $e) {
                //dd($groupConversation);
                throw $e;
            }
        }

        return $this->redirectToRoute('messages_browse', ['groupConversation' => $groupConversation->getId()] );
    }

    /**
     * Ping mercure
     * @Route("/{id}/ping", name="ping")
     */
    public function ping(Request $request, HubInterface $hub)
    {
        $this->denyAccessUnlessGranted('ROLE_USER');

        $update = new Update(
            '/ping/' .  $request->get('id'), //IRI, the topic being updated, can be any string usually URL
            json_encode(['message' => 'pinged !']), //the content of the update, can be anything
            false, //private
            'ping-' . Uuid::v4(), //mercure id
            'ping'
        );

        $hub->publish($update);

        return $this->redirectToRoute('messages_browse', ['groupConversation' => $request->get('id')]);
    }
}

like so

Answer 1

I don't know what $groupConversation->addMessage() does internally, but I can't see where the $message or $groupConversation get persisted to the entity manager, so they can be added to the DB when it is flushed and have IDs generated if required.

Only after they are flushed, would I publish the update to the Mercure $hub.