How to Use Multiple Transports

Symfony UX Turbo allows sending Turbo Streams updates using multiple transports. For instance, it's possible to use several Mercure hubs with the following configuration:

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        # config/packages/mercure.yaml
mercure:
    hubs:
        hub1:
            url: https://hub1.example.net/.well-known/mercure
            jwt: snip
        hub2:
            url: https://hub2.example.net/.well-known/mercure
            jwt: snip
    

Use the appropriate Mercure HubInterface service to send a change using a specific transport:

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        // src/Controller/TaskController.php
namespace App\Controller;

use Symfony\Bundle\FrameworkBundle\Controller\AbstractController;
use Symfony\Component\HttpFoundation\Response;
use Symfony\Component\Mercure\HubInterface;
use Symfony\Component\Mercure\Update;
use Symfony\Component\Routing\Attribute\Route;

#[Route('/task')]
class TaskController extends AbstractController
{
    #[Route('/publish', name: 'app_task_publish', methods: ['POST'])]
    public function publish(HubInterface $hub1): Response
    {
        $id = $hub1->publish(new Update('tasks', 'content'));

        return new Response("Update #{$id} published.");
    }
}
    

Changes made to entities marked with the #[Broadcast] attribute will be sent using all configured transports by default. You can specify the list of transports to use for a specific entity class using the transports parameter:

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        // src/Entity/Task.php
namespace App\Entity;

use Doctrine\ORM\Mapping as ORM;
use Symfony\UX\Turbo\Attribute\Broadcast;

#[ORM\Entity]
#[Broadcast(transports: ['hub1', 'hub2'])]
class Task
{
    #[ORM\Id]
    #[ORM\GeneratedValue]
    #[ORM\Column]
    private ?int $id = null;

    #[ORM\Column(length: 255)]
    private ?string $title = null;
}
    

Finally, generate the HTML attributes registering the Stimulus controller corresponding to your transport by passing an extra argument to turbo_stream_listen():

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        <div id="tasks" {{ turbo_stream_listen('App\\Entity\\Task', 'hub2') }}></div>
    

This work, including the code samples, is licensed under a Creative Commons BY-SA 3.0 license.

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