ExceptionListener.php

1. 9.x drupal/core/lib/Drupal/Core/EventSubscriber/ExceptionListener.php
2. 9.x drupal/core/vendor/symfony/http-kernel/Symfony/Component/HttpKernel/EventListener/ExceptionListener.php

<?php

/*
 * @file
 * Definition of Drupal\Core\EventSubscriber\ExceptionListener.
 */
namespace Drupal\Core\EventSubscriber;

use Symfony\Component\HttpKernel\Event\GetResponseForExceptionEvent;
use Symfony\Component\HttpKernel\KernelEvents;
use Symfony\Component\HttpKernel\HttpKernelInterface;
use Symfony\Component\HttpKernel\Exception\FlattenException;
use Symfony\Component\HttpKernel\Exception\HttpExceptionInterface;
use Symfony\Component\EventDispatcher\EventSubscriberInterface;

/**
 * Override of Symfony EventListener class to kill 403 and 404 from server logs.
 *
 * This is mostly a copy of Symfony's ExceptionListener but it doesn't have a
 * $logger property as we are not currently using a logger. The class from
 * Symfony will, in the absense of a logger, call error_log() on every http
 * exception.
 *
 * @todo Remove this class once we introduce a logger.
 *
 * @see http://drupal.org/node/1803338
 */
class ExceptionListener implements EventSubscriberInterface {
  private $controller;
  public function __construct($controller) {
    $this->controller = $controller;
  }
  public function onKernelException(GetResponseForExceptionEvent $event) {
    static $handling;
    if ($handling) {
      return FALSE;
    }
    $handling = TRUE;
    $exception = $event
      ->getException();
    $request = $event
      ->getRequest();

    // Do not put a line in the server logs for every HTTP error.
    if (!$exception instanceof HttpExceptionInterface || $exception
      ->getStatusCode() >= 500) {
      error_log(sprintf('Uncaught PHP Exception %s: "%s" at %s line %s', get_class($exception), $exception
        ->getMessage(), $exception
        ->getFile(), $exception
        ->getLine()));
    }
    $attributes = array(
      '_controller' => $this->controller,
      'exception' => FlattenException::create($exception),
      'logger' => NULL,
      'format' => $request
        ->getRequestFormat(),
    );
    $request = $request
      ->duplicate(NULL, NULL, $attributes);
    $request
      ->setMethod('GET');
    try {
      $response = $event
        ->getKernel()
        ->handle($request, HttpKernelInterface::SUB_REQUEST, TRUE);
    } catch (\Exception $e) {
      $message = sprintf('Exception thrown when handling an exception (%s: %s)', get_class($e), $e
        ->getMessage());
      error_log($message);

      // Set handling to false otherwise it won't be able to handle further
      // exceptions.
      $handling = FALSE;
      return;
    }
    $event
      ->setResponse($response);
    $handling = FALSE;
  }
  public static function getSubscribedEvents() {
    return array(
      KernelEvents::EXCEPTION => array(
        'onKernelException',
        -128,
      ),
    );
  }

}