Symfony4: 自前のアノテーションでコントローラ制御 https://karafuru-ramune.com/blog/827c536bef00d652d1d08de69d49a1eb

services.yaml

# EventListenerはAutowiringではなくマニュアルで設定
# ちなみにEventSubscriberはAutowiring可能
# https://symfony.com/doc/current/doctrine/event_listeners_subscribers.html
services:
    App\EventListener\XMLHttpRequestListener:
        tags:
            - { name: kernel.event_listener, event: kernel.request }
        arguments:
            - '@annotations.reader'
            - '@controller_resolver'
            - '@router'

XHRController.php

<?php
namespace App\Controller;

use App\Annotation\XMLHttpRequest;
use Sensio\Bundle\FrameworkExtraBundle\Configuration\Method;
use Sensio\Bundle\FrameworkExtraBundle\Configuration\Route;
use Symfony\Bundle\FrameworkBundle\Controller\Controller;
use Symfony\Component\HttpFoundation\Request;

/**
 * @XMLHttpRequest()
 */
class XHRController extends Controller
{
    /**
     * メソッドのアノテーションが優先される
     *
     * @Route("/xhr", name="list")
     * @Method("GET")
     * @XMLHttpRequest("index")
     */
    public function list() {...}
    
    /**
     * メソッドにアノテーションが付いていない場合は、クラスのアノテーションで動作
     *
     * @Route("/xhr", name="post")
     * @Method("POST")
     */
    public function post() {...}
}

XMLHttpRequest.php

<?php
namespace App\Annotation;

use Doctrine\Common\Annotations\Annotation;

/**
 * アノテーション
 *
 * @Annotation
 */
class XMLHttpRequest
{
    public $value;
}

XMLHttpRequestListener.php

<?php
namespace App\EventListener;

use App\Annotation\XMLHttpRequest;
use Doctrine\Common\Annotations\AnnotationReader;
use Symfony\Bundle\FrameworkBundle\Routing\Router;
use Symfony\Component\HttpFoundation\RedirectResponse;
use Symfony\Component\HttpKernel\Controller\ControllerResolverInterface;
use Symfony\Component\HttpKernel\Event\GetResponseEvent;
use Symfony\Component\HttpKernel\Exception\BadRequestHttpException;
use Symfony\Component\HttpKernel\Exception\NotFoundHttpException;

class XMLHttpRequestListener
{
    /** @var AnnotationReader */
    private $reader;
    
    /** @var ControllerResolverInterface */
    private $resolver;
    
    /** @var Router */
    private $router;
    
    public function __construct(
        AnnotationReader $reader,
        ControllerResolverInterface $resolver,
        Router $router
    )
    {
        $this->reader = $reader;
        $this->resolver = $resolver;
        $this->router = $router;
    }
    
    public function onKernelRequest(GetResponseEvent $event)
    {
        // twigのcontroller renderなど、サブリクエストはアノテーション処理しない
        if (!$event->isMasterRequest()) {
            return;
        }
        // アノテーション取得
        $annotations = $this->getAnnotations($event);
        
        foreach ($annotations as $annotation) {
            // XMLHttpRequestアノテーションでない場合はスキップ
            if (!($annotation instanceof XMLHttpRequest)) {
                continue;
            }
            
            // X-Requested-Withヘッダーを持っている場合はスキップ
            if ($event->getRequest()->isXmlHttpRequest()) {
                continue;
            }
            
            // 以下から、4xxや別ページに飛ばしたりする処理
            
            if (!is_string($annotation->value) || trim($annotation->value) === '') {
                throw new BadRequestHttpException();
            }
            try {
                $url = $this->router->generate($annotation->value);
                $event->setResponse(new RedirectResponse($url));
            } catch (\Exception $e) {
                throw new NotFoundHttpException($e);
            }
            
            return;
        }
    }
    
    private function getAnnotations(GetResponseEvent $event)
    {
        // $controller[0]にコントローラのオブジェクト、$controller[1]にメソッド名
        $controller = $this->resolver->getController($event->getRequest());
        $class = get_class($controller[0]);
        $methodName = $controller[1];
        
        if (!class_exists($class)) {
            throw new \AssertionError('class does not exist: ' . $class);
        }
        
        $reflection = new \ReflectionClass($class);
        
        return array_merge(
            $this->reader->getMethodAnnotations($reflection->getMethod($methodName)),
            $this->reader->getClassAnnotations($reflection)
        );
    }
}