PathAliasSubscriber.php

<?php

namespace Drupal\path_alias\EventSubscriber;

use Drupal\Core\Path\CurrentPathStack;
use Drupal\path_alias\AliasManagerInterface;
use Symfony\Component\EventDispatcher\EventSubscriberInterface;
use Symfony\Component\HttpKernel\KernelEvents;
use Symfony\Component\HttpKernel\Event\ControllerEvent;
use Symfony\Component\HttpKernel\Event\TerminateEvent;

/**
 * Provides a path subscriber that converts path aliases.
 */
class PathAliasSubscriber implements EventSubscriberInterface {
    
    /**
     * The alias manager that caches alias lookups based on the request.
     *
     * @var \Drupal\path_alias\AliasManagerInterface
     */
    protected $aliasManager;
    
    /**
     * The current path.
     *
     * @var \Drupal\Core\Path\CurrentPathStack
     */
    protected $currentPath;
    
    /**
     * Constructs a new PathSubscriber instance.
     *
     * @param \Drupal\path_alias\AliasManagerInterface $alias_manager
     *   The alias manager.
     * @param \Drupal\Core\Path\CurrentPathStack $current_path
     *   The current path.
     */
    public function __construct(AliasManagerInterface $alias_manager, CurrentPathStack $current_path) {
        $this->aliasManager = $alias_manager;
        $this->currentPath = $current_path;
    }
    
    /**
     * Sets the cache key on the alias manager cache decorator.
     *
     * KernelEvents::CONTROLLER is used in order to be executed after routing.
     *
     * @param \Symfony\Component\HttpKernel\Event\ControllerEvent $event
     *   The Event to process.
     */
    public function onKernelController(ControllerEvent $event) {
        // Set the cache key on the alias manager cache decorator.
        if ($event->isMainRequest()) {
            $this->aliasManager
                ->setCacheKey(rtrim($this->currentPath
                ->getPath($event->getRequest()), '/'));
        }
    }
    
    /**
     * Ensures system paths for the request get cached.
     */
    public function onKernelTerminate(TerminateEvent $event) {
        $this->aliasManager
            ->writeCache();
    }
    
    /**
     * Registers the methods in this class that should be listeners.
     *
     * @return array
     *   An array of event listener definitions.
     */
    public static function getSubscribedEvents() {
        $events[KernelEvents::CONTROLLER][] = [
            'onKernelController',
            200,
        ];
        $events[KernelEvents::TERMINATE][] = [
            'onKernelTerminate',
            200,
        ];
        return $events;
    }

}