Enable controller service with #[Route] attribute in Symfony < 7.3

README.md

It's possible to backport into an older Symfony project the new feature for Symfony 7.3 that automatically register classes declaring #[Route] attribute for injection of services into the controller.

symfony/symfony#60081

You need to update your App\Kernel class to register the attribute autoconfiguration.

Kernel.php

<?php


namespace App;

use Symfony\Bundle\FrameworkBundle\Kernel\MicroKernelTrait;
use Symfony\Component\DependencyInjection\ChildDefinition;
use Symfony\Component\DependencyInjection\ContainerBuilder;
use Symfony\Component\HttpKernel\Kernel as BaseKernel;
use Symfony\Component\Routing\Attribute\Route;

class Kernel extends BaseKernel
{
    use MicroKernelTrait;

    public function build(ContainerBuilder $container): void
    {
        $container->registerAttributeForAutoconfiguration(Route::class, static function (ChildDefinition $definition, Route $attribute, \ReflectionClass|\ReflectionMethod $reflection): void {
            $definition->addTag('controller.service_arguments');
        });
    }
}