a12s-1.0.0-beta7/src/EventSubscriber/PhpErrorsSubscriber.php

<?php

namespace Drupal\a12s_core\EventSubscriber;

use Drupal\Component\Plugin\Exception\InvalidPluginDefinitionException;
use Drupal\Component\Plugin\Exception\PluginNotFoundException;
use Drupal\Core\Cache\CacheBackendInterface;
use Drupal\Core\Entity\EntityTypeManagerInterface;
use Drupal\Core\EventSubscriber\MainContentViewSubscriber;
use Drupal\Core\Render\BareHtmlPageRendererInterface;
use Drupal\Core\StringTranslation\StringTranslationTrait;
use Symfony\Component\EventDispatcher\EventSubscriberInterface;
use Symfony\Component\HttpFoundation\RedirectResponse;
use Symfony\Component\HttpKernel\Event\ExceptionEvent;
use Symfony\Component\HttpKernel\KernelEvents;

/**
 * Service for handling some PHP errors.
 *
 * The maintenance page is displayed when possible, instead of a raw page.
 */
class PhpErrorsSubscriber implements EventSubscriberInterface {

  use StringTranslationTrait;

  /**
   * Constructs a new MaintenanceModeSubscriber.
   *
   * @param \Drupal\Core\Render\BareHtmlPageRendererInterface $bareHtmlPageRenderer
   *   The bare HTML page renderer.
   * @param \Drupal\Core\Entity\EntityTypeManagerInterface $entityTypeManager
   *   The entity type manager.
   * @param \Drupal\Core\Cache\CacheBackendInterface $cacheDiscovery
   *   The cache backend for plugin discovery.
   */
  public function __construct(
    protected BareHtmlPageRendererInterface $bareHtmlPageRenderer,
    protected EntityTypeManagerInterface $entityTypeManager,
    protected CacheBackendInterface $cacheDiscovery
  ) {}

  /**
   * {@inheritdoc}
   */
  public static function getSubscribedEvents(): array {
    // Take care of errors that have not been handled by other subscribers, but
    // just before the last subscriber (256).
    $events[KernelEvents::EXCEPTION][] = ['onException', -255];
    return $events;
  }

  /**
   * Take care of errors that are not handled by anyone.
   *
   * @param \Symfony\Component\HttpKernel\Event\ExceptionEvent $event
   *   The event to process.
   */
  public function onException(ExceptionEvent $event): void {
    if (!$event->isMainRequest()) {
      return;
    }

    $exception = $event->getThrowable();

    // There is a very old issue with paragraph entity type, where the
    // "translation" handler is missing from the entity type definition.
    // In such case, a simple rebuild of the entity cache fixes the issue.
    // It seems that the "content_translation_entity_type_alter()" hook
    // is missing for some unclear reasons.
    // @see https://www.drupal.org/project/paragraphs/issues/3031598
    if ($exception instanceof InvalidPluginDefinitionException && $exception->getPluginId() === 'paragraph') {
      try {
        $entityType = $this->entityTypeManager->getDefinition('paragraph');

        if (!$entityType->hasHandlerClass('translation')) {
          // Rebuild the entity_type cache discovery, so the definition of the
          // paragraph entity type will be rebuilt on next call.
          $this->cacheDiscovery->delete('entity_type');

          // Reload current page. Note that we loose the anchor part if any.
          $request = $event->getRequest();
          $format = $request->query->get(MainContentViewSubscriber::WRAPPER_FORMAT, $request->getRequestFormat());

          // Do not try to redirect non-HTML request, as it may lead to bigger
          // errors than the one we try to fix.
          if ($format == 'html') {
            $url = $request->getSchemeAndHttpHost() . $request->getRequestUri();

            if (!empty($request->getQueryString())) {
              $url .= '?' . $request->getQueryString();
            }

            $response = new RedirectResponse($url, 302, ['Cache-Control' => 'no-cache']);
            $event->setResponse($response);
            return;
          }
        }
      }
      catch (PluginNotFoundException $e) {
        // Pass through.
      }
    }

    $request = $event->getRequest();
    $format = $request->query->get(MainContentViewSubscriber::WRAPPER_FORMAT, $request->getRequestFormat());

    if ($format === 'html') {
      drupal_maintenance_theme();
      $response = $this->bareHtmlPageRenderer->renderBarePage(
        ['#markup' => $this->t('The website encountered an unexpected error. Please try again later.')],
        $this->t('Unexpected error'),
        'maintenance_page'
      );
      $event->setResponse($response);
    }
  }

}