function _drupal_log_error

Logs a PHP error or exception and displays an error page in fatal cases.

Parameters

$error: An array with the following keys: %type, @message, %function, %file, %line, @backtrace_string, severity_level, backtrace, and exception. All the parameters are plain-text, with the exception of @message, which needs to be an HTML string, backtrace, which is a standard PHP backtrace, and exception, which is the exception object (or NULL if the error is not an exception).

bool $fatal: TRUE for:

• An exception is thrown and not caught by something else.
• A recoverable fatal error, which is a fatal error.

Non-recoverable fatal errors cannot be logged by Drupal.

File

core/includes/errors.inc, line 149

Functions for error handling.

Code

function _drupal_log_error($error, $fatal = FALSE) {
  $is_installer = InstallerKernel::installationAttempted();

  // Backtrace, exception and 'severity_level' are not valid replacement values
  // for t().
  $backtrace = $error['backtrace'];
  $exception = $error['exception'];
  $severity = $error['severity_level'];
  unset($error['backtrace'], $error['exception'], $error['severity_level']);

  // When running inside the testing framework, we relay the errors
  // to the tested site by the way of HTTP headers.
  if (DRUPAL_TEST_IN_CHILD_SITE && !headers_sent() && (!defined('SIMPLETEST_COLLECT_ERRORS') || SIMPLETEST_COLLECT_ERRORS)) {
    _drupal_error_header($error['@message'], $error['%type'], $error['%function'], $error['%file'], $error['%line']);
  }
  $response = new Response();

  // Only call the logger if there is a logger factory available. This can occur
  // if there is an error while rebuilding the container or during the
  // installer.
  if (\Drupal::hasService('logger.factory')) {
    try {

      // Provide the PHP backtrace and exception to logger implementations. Add
      // 'severity_level' to the context to maintain BC and allow logging
      // implementations to use it.
      \Drupal::logger('php')
        ->log($severity, '%type: @message in %function (line %line of %file) @backtrace_string.', $error + [
        'backtrace' => $backtrace,
        'exception' => $exception,
        'severity_level' => $severity,
      ]);
    } catch (\Exception $e) {

      // We can't log, for example because the database connection is not
      // available. At least try to log to PHP error log.
      error_log(strtr('Failed to log error: ' . Error::DEFAULT_ERROR_MESSAGE . ' @backtrace_string', $error));
    }
  }

  // Log fatal errors, so developers can find and debug them.
  if ($fatal) {
    error_log(sprintf('%s: %s in %s on line %d %s', $error['%type'], $error['@message'], $error['%file'], $error['%line'], $error['@backtrace_string']));
  }
  if (PHP_SAPI === 'cli') {
    if ($fatal) {

      // When called from CLI, simply output a plain text message.
      // Should not translate the string to avoid errors producing more errors.
      $response
        ->setContent(html_entity_decode(strip_tags(new FormattableMarkup(Error::DEFAULT_ERROR_MESSAGE, $error))) . "\n");
      $response
        ->send();
      exit(1);
    }
  }
  if (\Drupal::hasRequest() && \Drupal::request()
    ->isXmlHttpRequest()) {
    if ($fatal) {
      if (error_displayable($error)) {

        // When called from JavaScript, simply output the error message.
        // Should not translate the string to avoid errors producing more errors.
        $response
          ->setContent(new FormattableMarkup(Error::DEFAULT_ERROR_MESSAGE, $error));
        $response
          ->send();
      }
      exit;
    }
  }
  else {

    // Display the message if the current error reporting level allows this type
    // of message to be displayed, and unconditionally in update.php.
    $message = '';
    $class = NULL;
    if (error_displayable($error)) {
      $class = 'error';

      // If error type is 'User notice' then treat it as debug information
      // instead of an error message.
      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.
      if (\Drupal::hasService('kernel')) {
        $root_length = strlen(\Drupal::root());
        if (substr($error['%file'], 0, $root_length) == \Drupal::root()) {
          $error['%file'] = substr($error['%file'], $root_length + 1);
        }
      }

      // Check if verbose error reporting is on.
      $error_level = _drupal_get_error_level();
      if ($error_level != ERROR_REPORTING_DISPLAY_VERBOSE) {

        // Without verbose logging, use a simple message.
        // We use \Drupal\Component\Render\FormattableMarkup directly here,
        // rather than use t() since we are in the middle of error handling, and
        // we don't want t() to cause further errors.
        $message = new FormattableMarkup(Error::DEFAULT_ERROR_MESSAGE, $error);
      }
      else {

        // With verbose logging, we will also include a backtrace.
        // 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.
        $error['@backtrace'] = Error::formatBacktrace($backtrace);
        $message = new FormattableMarkup('<details class="error-with-backtrace"><summary>' . Error::DEFAULT_ERROR_MESSAGE . '</summary><pre class="backtrace">@backtrace</pre></details>', $error);
      }
    }
    if ($fatal) {

      // We fallback to a maintenance page at this point, because the page generation
      // itself can generate errors.
      // Should not translate the string to avoid errors producing more errors.
      $message = 'The website encountered an unexpected error. Try again later.' . '<br />' . $message;
      if ($is_installer) {

        // install_display_output() prints the output and ends script execution.
        $output = [
          '#title' => 'Error',
          '#markup' => $message,
        ];
        install_display_output($output, $GLOBALS['install_state']);
        exit;
      }
      $response
        ->setContent($message);
      $response
        ->setStatusCode(500, '500 Service unavailable (with message)');
      $response
        ->send();

      // An exception must halt script execution.
      exit;
    }
    if ($message) {
      if (\Drupal::hasService('session')) {

        // Message display is dependent on sessions being available.
        \Drupal::messenger()
          ->addMessage($message, $class, TRUE);
      }
      else {
        print $message;
      }
    }
  }
}