xdebug/blog/vendor/symfony/http-kernel/Controller/ArgumentResolver/ServiceValueResolver.php

<?php

/*
 * This file is part of the Symfony package.
 *
 * (c) Fabien Potencier <fabien@symfony.com>
 *
 * For the full copyright and license information, please view the LICENSE
 * file that was distributed with this source code.
 */

namespace Symfony\Component\HttpKernel\Controller\ArgumentResolver;

use Psr\Container\ContainerInterface;
use Symfony\Component\HttpFoundation\Request;
use Symfony\Component\HttpKernel\Controller\ArgumentValueResolverInterface;
use Symfony\Component\HttpKernel\ControllerMetadata\ArgumentMetadata;

/**
 * Yields a service keyed by _controller and argument name.
 *
 * @author Nicolas Grekas <p@tchwork.com>
 */
final class ServiceValueResolver implements ArgumentValueResolverInterface
{
    private $container;

    public function __construct(ContainerInterface $container)
    {
        $this->container = $container;
    }

    /**
     * {@inheritdoc}
     */
    public function supports(Request $request, ArgumentMetadata $argument)
    {
        return is_string($controller = $request->attributes->get('_controller')) && $this->container->has($controller) && $this->container->get($controller)->has($argument->getName());
    }

    /**
     * {@inheritdoc}
     */
    public function resolve(Request $request, ArgumentMetadata $argument)
    {
        yield $this->container->get($request->attributes->get('_controller'))->get($argument->getName());
    }
}