Select Git revision
DefaultExceptionSubscriber.php

#2457887 by prateekMehta, stefan.r, rpayanm, alexpott: Use...
Angie Byron authored
Issue #2457887 by prateekMehta, stefan.r, rpayanm, alexpott: Use Utility\SafeMarkup class instead of Utility\String for placeholder(), checkPlain(),format() functions
Code owners
Assign users and groups as approvers for specific file changes. Learn more.
DefaultExceptionSubscriber.php 8.32 KiB
<?php
/**
* @file
* Contains \Drupal\Core\EventSubscriber\DefaultExceptionSubscriber.
*/
namespace Drupal\Core\EventSubscriber;
use Drupal\Component\Utility\SafeMarkup;
use Drupal\Core\Config\ConfigFactoryInterface;
use Drupal\Core\Render\BareHtmlPageRendererInterface;
use Drupal\Core\StringTranslation\StringTranslationTrait;
use Drupal\Core\Utility\Error;
use Symfony\Component\EventDispatcher\EventSubscriberInterface;
use Symfony\Component\HttpFoundation\JsonResponse;
use Symfony\Component\HttpFoundation\Request;
use Symfony\Component\HttpFoundation\Response;
use Symfony\Component\HttpKernel\Event\GetResponseForExceptionEvent;
use Symfony\Component\HttpKernel\Exception\HttpExceptionInterface;
use Symfony\Component\HttpKernel\KernelEvents;
/**
* Last-chance handler for exceptions.
*
* This handler will catch any exceptions not caught elsewhere and report
* them as an error page.
*/
class DefaultExceptionSubscriber implements EventSubscriberInterface {
use StringTranslationTrait;
/**
* @var string
*
* One of the error level constants defined in bootstrap.inc.
*/
protected $errorLevel;
/**
* The config factory.
*
* @var \Drupal\Core\Config\ConfigFactoryInterface
*/
protected $configFactory;
/**
* The bare HTML page renderer.
*
* @var \Drupal\Core\Render\BareHtmlPageRendererInterface
*/
protected $bareHtmlPageRenderer;
/**
* Constructs a new DefaultExceptionSubscriber.
*
* @param \Drupal\Core\Config\ConfigFactoryInterface $config_factory
* The configuration factory.
* @param \Drupal\Core\Render\BareHtmlPageRendererInterface $bare_html_page_renderer
* The bare HTML page renderer.
*/
public function __construct(ConfigFactoryInterface $config_factory, BareHtmlPageRendererInterface $bare_html_page_renderer) {
$this->configFactory = $config_factory;
$this->bareHtmlPageRenderer = $bare_html_page_renderer;
}
/**
* Gets the configured error level.
*
* @return string
*/
protected function getErrorLevel() {
if (!isset($this->errorLevel)) {
$this->errorLevel = $this->configFactory->get('system.logging')->get('error_level');
}
return $this->errorLevel;
}
/**
* Handles any exception as a generic error page for HTML.
*
* @param \Symfony\Component\HttpKernel\Event\GetResponseForExceptionEvent $event
* The event to process.
*/
protected function onHtml(GetResponseForExceptionEvent $event) {
$exception = $event->getException();
$error = Error::decodeException($exception);
// Display the message if the current error reporting level allows this type
// of message to be displayed, and unconditionally in update.php.
if (error_displayable($error)) {
$class = 'error';
// If error type is 'User notice' then treat it as debug information
// instead of an error message.
// @see debug()
if ($error['%type'] == 'User notice') {
$error['%type'] = 'Debug';
$class = 'status';
}
// Attempt to reduce verbosity by removing DRUPAL_ROOT from the file path
// in the message. This does not happen for (false) security.
$root_length = strlen(DRUPAL_ROOT);
if (substr($error['%file'], 0, $root_length) == DRUPAL_ROOT) {
$error['%file'] = substr($error['%file'], $root_length + 1);
}
// Do not translate the string to avoid errors producing more errors.
unset($error['backtrace']);
$message = SafeMarkup::format('%type: !message in %function (line %line of %file).', $error);
// Check if verbose error reporting is on.
if ($this->getErrorLevel() == ERROR_REPORTING_DISPLAY_VERBOSE) {
$backtrace_exception = $exception;
while ($backtrace_exception->getPrevious()) {
$backtrace_exception = $backtrace_exception->getPrevious();
}
$backtrace = $backtrace_exception->getTrace();
// First trace is the error itself, already contained in the message.
// While the second trace is the error source and also contained in the
// message, the message doesn't contain argument values, so we output it
// once more in the backtrace.
array_shift($backtrace);
// Generate a backtrace containing only scalar argument values. Make
// sure the backtrace is escaped as it can contain user submitted data.
$message .= '<pre class="backtrace">' . SafeMarkup::escape(Error::formatBacktrace($backtrace)) . '</pre>';
}
drupal_set_message(SafeMarkup::set($message), $class, TRUE);
}
$content = $this->t('The website has encountered an error. Please try again later.');
$output = $this->bareHtmlPageRenderer->renderBarePage(['#markup' => $content], $this->t('Error'), 'maintenance_page');
$response = new Response($output);
if ($exception instanceof HttpExceptionInterface) {
$response->setStatusCode($exception->getStatusCode());
$response->headers->add($exception->getHeaders());
}
else {
$response->setStatusCode(Response::HTTP_INTERNAL_SERVER_ERROR, '500 Service unavailable (with message)');
}
$event->setResponse($response);
}
/**
* Handles any exception as a generic error page for JSON.
*
* @todo This should probably check the error reporting level.
*
* @param \Symfony\Component\HttpKernel\Event\GetResponseForExceptionEvent $event
* The event to process.
*/
protected function onJson(GetResponseForExceptionEvent $event) {
$exception = $event->getException();
$error = Error::decodeException($exception);
// Display the message if the current error reporting level allows this type
// of message to be displayed,
$data = NULL;
if (error_displayable($error) && $message = $exception->getMessage()) {
$data = ['error' => sprintf('A fatal error occurred: %s', $message)];
}
$response = new JsonResponse($data, Response::HTTP_INTERNAL_SERVER_ERROR);
if ($exception instanceof HttpExceptionInterface) {
$response->setStatusCode($exception->getStatusCode());
$response->headers->add($exception->getHeaders());
}
$event->setResponse($response);
}
/**
* Handles errors for this subscriber.
*
* @param \Symfony\Component\HttpKernel\Event\GetResponseForExceptionEvent $event
* The event to process.
*/
public function onException(GetResponseForExceptionEvent $event) {
$format = $this->getFormat($event->getRequest());
// If it's an unrecognized format, assume HTML.
$method = 'on' . $format;
if (!method_exists($this, $method)) {
$method = 'onHtml';
}
$this->$method($event);
}
/**
* Gets the error-relevant format from the request.
*
* @param \Symfony\Component\HttpFoundation\Request $request
* The request object.
*
* @return string
* The format as which to treat the exception.
*/
protected function getFormat(Request $request) {
// @todo We are trying to switch to a more robust content negotiation
// library in https://www.drupal.org/node/1505080 that will make
// $request->getRequestFormat() reliable as a better alternative
// to this code. We therefore use this style for now on the expectation
// that it will get replaced with better code later. This approach makes
// that change easier when we get to it.
$format = \Drupal::service('http_negotiation.format_negotiator')->getContentType($request);
// These are all JSON errors for our purposes. Any special handling for
// them can/should happen in earlier listeners if desired.
if (in_array($format, ['drupal_modal', 'drupal_dialog', 'drupal_ajax'])) {
$format = 'json';
}
// Make an educated guess that any Accept header type that includes "json"
// can probably handle a generic JSON response for errors. As above, for
// any format this doesn't catch or that wants custom handling should
// register its own exception listener.
foreach ($request->getAcceptableContentTypes() as $mime) {
if (strpos($mime, 'html') === FALSE && strpos($mime, 'json') !== FALSE) {
$format = 'json';
}
}
return $format;
}
/**
* Registers the methods in this class that should be listeners.
*
* @return array
* An array of event listener definitions.
*/
public static function getSubscribedEvents() {
$events[KernelEvents::EXCEPTION][] = ['onException', -256];
return $events;
}
}