symfony-conventions

Symfony Conventions (6.4 / 7.x)

This skill encodes the conventions used across modern Symfony projects. Apply alongside php-foundation:php-conventions (language idioms) when implementing features.

1. Attribute routing

Routes are declared with #[Route] attributes on controller actions — not YAML/XML for new code.

namespace App\Controller;

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

#[Route('/subscriptions', name: 'subscription_')]
final class SubscriptionController extends AbstractController
{
    #[Route('/{id}', name: 'show', methods: ['GET'], requirements: ['id' => '\d+'])]
    public function show(int $id): Response
    {
        // ...
    }
}

A class-level #[Route] sets a path prefix and name prefix. Always set methods: explicitly. Use requirements: to constrain route params.

2. Controllers as services + thin actions

• Extend AbstractController (gives render(), json(), denyAccessUnlessGranted(), getUser()).
• A controller with #[Route] is automatically registered as a service with autowired action arguments.
• Keep actions thin: authorize → map/validate input → call a service → return a response. Business logic lives in services.

public function __construct(
    private readonly SubscriptionManager $subscriptions,
) {
}

#[Route('', name: 'store', methods: ['POST'])]
public function store(#[MapRequestPayload] CreateSubscriptionRequest $request): Response
{
    $this->denyAccessUnlessGranted('SUBSCRIPTION_CREATE');

    $subscription = $this->subscriptions->create($this->getUser(), $request);

    return $this->redirectToRoute('subscription_show', ['id' => $subscription->getId()]);
}

#[MapRequestPayload] deserializes + validates the request body into a DTO automatically.

3. Dependency injection / autowiring

• Constructor injection only. Never property injection or @required setters for new code.
• Services are autowired + autoconfigured by default (config/services.yaml _defaults: autowire: true, autoconfigure: true).
• Inject scalars/parameters with #[Autowire]: