EventSubscriber exemple

<?php

namespace Drupal\MY_MODULE\EventSubscriber;

use Drupal\Core\Session\AccountInterface;
use Drupal\taxonomy\TermInterface;
use Symfony\Component\EventDispatcher\EventSubscriberInterface;
use Symfony\Component\HttpKernel\Event\GetResponseEvent;
use Symfony\Component\HttpKernel\KernelEvents;
use Symfony\Component\HttpKernel\Exception\NotFoundHttpException;
use Drupal\Core\Routing\RouteMatch;

/**
 * Class Subscriber.
 *
 * @package Drupal\MY_MODULE
 */
class TermAccessSubscriber implements EventSubscriberInterface {

  /**
   * the terms allowed to be accessed on their canonical page.
   *
   * @var array
   */
  protected $allowed_terms;

  /**
   * The current user.
   *
   * @var \Drupal\Core\Session\AccountInterface
   */
  protected $currentUser;

  /**
   * Constructor.
   *
   * @param \Drupal\Core\Session\AccountInterface $current_user
   *   The current user.
   */
  public function __construct(AccountInterface $current_user) {
    $this->currentUser = $current_user;
    $this->allowed_terms = [
      'service',
      'expertise',
      'territory',
      'keyword',
      'newsletter',
    ];
  }

  /**
   * {@inheritdoc}
   */
  static function getSubscribedEvents() {
    $events[KernelEvents::REQUEST] = ['onRequestRedirect'];
    return $events;
  }

  /**
   * This method is called whenever the kernel.request event is
   * dispatched.
   *
   * @param GetResponseEvent $event
   */
  public function onRequestRedirect(GetResponseEvent $event) {
    $request = $event->getRequest();

    if ($this->currentUser->hasPermission('administer taxonomy')) {
      return;
    }

    // If we've got an exception, nothing to do here.
    if ($request->get('exception') != NULL) {
      return;
    }

    /** @var \Drupal\taxonomy\Entity\Term $term */
    $term = $request->get('taxonomy_term');
    $route_match = RouteMatch::createFromRequest($request);
    $route_name = $route_match->getRouteName();
    if ($term instanceof TermInterface && $route_name == 'entity.taxonomy_term.canonical') {
      if (!in_array($term->bundle(), $this->allowed_terms)) {
        throw new NotFoundHttpException();
      }
    }

  }

}