Routing

Attribute routes are your React Router / Vue Router config - but for the server. You've already built the toy version.

Basic routes

<?php

namespace App\Controller;

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

class HelloController extends AbstractController
{
    #[Route('/', name: 'app_home')]
    public function home(): Response
    {
        return $this->render('home.html.twig');
    }

    #[Route('/hello/{name}', name: 'app_hello')]
    public function hello(string $name): Response
    {
        return new Response("Hello, {$name}");
    }

    #[Route('/posts', name: 'app_posts_index', methods: ['GET'])]
    public function index(): Response
    {
        // …
    }
}

Comments for the code above:

• {name} is the same idea as your mini-router params
• name: 'app_posts_index' gives you stable links (path('app_posts_index') in Twig / $this->generateUrl(...)) so URLs can change without hunting strings
• methods: restricts verbs - browser forms only do GET/POST natively

Path requirements & defaults

<?php

#[Route('/posts/{id}', name: 'app_posts_show', requirements: ['id' => '\d+'])]
public function show(int $id): Response
{
    // …
}

As you can see, requirements are just regex constraints on placeholders.

Prefixes via class attributes

<?php

#[Route('/dashboard')]
class DashboardController extends AbstractController
{
    #[Route('', name: 'app_dashboard')]
    public function index(): Response { /* … */ }

    #[Route('/settings', name: 'app_dashboard_settings')]
    public function settings(): Response { /* … */ }
}

Inspecting routes

php bin/console debug:router
php bin/console debug:router app_posts_show

When a URL 404s mysteriously, debug:router is the first stop - same energy as php artisan route:list.

YAML / XML routes?

Still exist. Modern apps lean on attributes on controllers. If you open an older codebase and see config/routes.yaml full of path definitions - same router, different syntax.

Next: controllers as thin HTTP adapters.

Best,

-- ł.