http_handler.module

<?php

/**
 * @file
 * Enables the ability to return correct HTTP Status code.
 */

use Drupal\http_handler\Component\Enum\HttpStatusCodeEnum;

/**
 * Implements hook_help().
 *
 * @see https://api.drupal.org/api/drupal/modules%21system%21system.api.php/function/hook_help/7.x
 */
function http_handler_help($path, $arg) {
  switch ($path) {
    case 'admin/help#http_handler':
      $output = '<pre>';
      $filepath = drupal_get_path('module', 'http_handler') . DIRECTORY_SEPARATOR . 'README.md';
      if (file_exists($filepath)) {
        if ($readme = file_get_contents($filepath)) {
          $output .= $readme;
          if (module_exists('markdown')) {
            $filters = module_invoke('markdown', 'filter_info');
            $info = $filters['filter_markdown'];
            if (function_exists($info['process callback'])) {
              $output = $info['process callback']($readme, NULL);
            }
          }
        }
      }
      $output .= '</pre>';
      break;

    default:
      $output = '';
      break;
  }
  return $output;
}

/**
 * Implements hook_init().
 *
 * @see https://api.drupal.org/api/drupal/modules%21system%21system.api.php/function/hook_init/7
 */
function http_handler_init() {
  module_load_include('inc', 'http_handler', 'includes/http_handler.functions');
  set_exception_handler('http_handler_exception_handler');
}

/**
 * Implements hook_page_delivery_callback_alter().
 *
 * @see https://api.drupal.org/api/drupal/modules%21system%21system.api.php/function/hook_page_delivery_callback_alter/7.x
 */
function http_handler_page_delivery_callback_alter(&$callback) {
  if ($callback == 'drupal_deliver_html_page') {
    $callback = 'http_handler_deliver_html_page';
  }
}

/**
 * Implements hook_form_FORM_ID_alter().
 *
 * @see https://api.drupal.org/api/drupal/modules%21system%21system.api.php/function/hook_form_FORM_ID_alter/7.x
 */
function http_handler_form_system_site_information_settings_alter(&$form, &$form_state, $form_id) {
  $clean_url = variable_get('clean_url', 0);
  $default_site_403 = variable_get('site_403', '');

  $form['error_page']['site_' . HttpStatusCodeEnum::HTTP_BAD_REQUEST] = array(
    '#type' => 'textfield',
    '#title' => t('Default @code (@text) page', array('@code' => HttpStatusCodeEnum::HTTP_BAD_REQUEST, '@text' => 'bad request')),
    '#default_value' => variable_get('site_' . HttpStatusCodeEnum::HTTP_BAD_REQUEST, $default_site_403),
    '#size' => 40,
    '#description' => t(
      'This page is displayed when the requested document is on error to the current user. Leave blank to display a generic "@text" page.',
      array('@text' => 'bad request')
    ),
    '#field_prefix' => url(NULL, array('absolute' => TRUE)) . ($clean_url ? '' : '?q='),
  );
  $form['error_page']['site_' . HttpStatusCodeEnum::HTTP_UNAUTHORIZED] = array(
    '#type' => 'textfield',
    '#title' => t('Default @code (@text) page', array('@code' => HttpStatusCodeEnum::HTTP_UNAUTHORIZED, '@text' => 'unauthorized')),
    '#default_value' => variable_get('site_' . HttpStatusCodeEnum::HTTP_UNAUTHORIZED, $default_site_403),
    '#size' => 40,
    '#description' => t(
      'This page is displayed when the requested document is on error to the current user. Leave blank to display a generic "@text" page.',
      array('@text' => 'unauthorized')
    ),
    '#field_prefix' => url(NULL, array('absolute' => TRUE)) . ($clean_url ? '' : '?q='),
  );
  $form['error_page']['site_' . HttpStatusCodeEnum::HTTP_METHOD_NOT_ALLOWED] = array(
    '#type' => 'textfield',
    '#title' => t('Default @code (@text) page', array('@code' => HttpStatusCodeEnum::HTTP_METHOD_NOT_ALLOWED, '@text' => 'method not allowed')),
    '#default_value' => variable_get('site_' . HttpStatusCodeEnum::HTTP_METHOD_NOT_ALLOWED, $default_site_403),
    '#size' => 40,
    '#description' => t(
      'This page is displayed when the requested document is on error to the current user. Leave blank to display a generic "@text" page.',
      array('@text' => 'method not allowed')
    ),
    '#field_prefix' => url(NULL, array('absolute' => TRUE)) . ($clean_url ? '' : '?q='),
  );

  $form['#validate'][] = 'http_handler_system_site_information_settings_validate';
}

/**
 * Validates the submitted site-information form.
 *
 * Callback for http_handler_form_system_site_information_settings_alter().
 *
 * @param array $form
 *   Nested array of form elements that comprise the form.
 * @param array $form_state
 *   A keyed array containing the current state of the form.
 *
 * @see system_site_information_settings_validate()
 */
function http_handler_system_site_information_settings_validate(array $form, array &$form_state) {
  // Validate 400 error path.
  if (
   !empty($form_state['values']['site_' . HttpStatusCodeEnum::HTTP_BAD_REQUEST])
   && !drupal_valid_path($form_state['values']['site_' . HttpStatusCodeEnum::HTTP_BAD_REQUEST])
   ) {
    form_set_error('site_' . HttpStatusCodeEnum::HTTP_BAD_REQUEST, t('The path "@path" is either invalid or you do not have access to it.', array('@path' => $form_state['values']['site_' . HttpStatusCodeEnum::HTTP_BAD_REQUEST])));
  }

  // Validate 401 error path.
  if (
   !empty($form_state['values']['site_' . HttpStatusCodeEnum::HTTP_UNAUTHORIZED])
   && !drupal_valid_path($form_state['values']['site_' . HttpStatusCodeEnum::HTTP_UNAUTHORIZED])
   ) {
    form_set_error('site_' . HttpStatusCodeEnum::HTTP_UNAUTHORIZED, t('The path "@path" is either invalid or you do not have access to it.', array('@path' => $form_state['values']['site_' . HttpStatusCodeEnum::HTTP_UNAUTHORIZED])));
  }

  // Validate 405 error path.
  if (
   !empty($form_state['values']['site_' . HttpStatusCodeEnum::HTTP_METHOD_NOT_ALLOWED])
   && !drupal_valid_path($form_state['values']['site_' . HttpStatusCodeEnum::HTTP_METHOD_NOT_ALLOWED])
   ) {
    form_set_error('site_' . HttpStatusCodeEnum::HTTP_METHOD_NOT_ALLOWED, t('The path "@path" is either invalid or you do not have access to it.', array('@path' => $form_state['values']['site_' . HttpStatusCodeEnum::HTTP_METHOD_NOT_ALLOWED])));
  }
}

/**
 * Change the exception handler.
 *
 * Callback for http_handler_init().
 *
 * @param \Exception $exception
 *   The exception raised.
 *
 * @todo be more specific for exception and add an alter
 */
function http_handler_exception_handler(\Exception $exception) {
  watchdog_exception('http_handler', $exception);
  switch (TRUE) {
    case $exception instanceof \LogicException:
      restore_exception_handler();
      throw $exception;

    case $exception instanceof \BadFunctionCallException:
      // No break.
    case $exception instanceof \BadMethodCallException:
      drupal_method_not_allowed();
      break;

    case $exception instanceof \DomainException:
      // No break.
    case $exception instanceof \RangeException:
      // No break.
    case $exception instanceof \LengthException:
      // No break.
    case $exception instanceof \InvalidArgumentException:
      // No break.
    case $exception instanceof \UnexpectedValueException:
      // No break.
    case $exception instanceof \RuntimeException:
      drupal_bad_request();
      break;

    case $exception instanceof \UnderflowException:
      drupal_gone();
      break;

    case $exception instanceof \LogicException:
      // No break.
    case $exception instanceof \OutOfBoundsException:
      // No break.
    case $exception instanceof \OutOfRangeException:
      // No break.
    case $exception instanceof \OverflowException:
      // No break.
    default:
      _drupal_exception_handler($exception);
      break;
  }
}

/**
 * Packages and sends the result of a page callback to the browser as HTML.
 *
 * Callback for http_handler_page_delivery_callback_alter().
 *
 * @param mixed $page_callback_result
 *   The result of a page callback. Can be one of:
 *   - null: to indicate no content.
 *   - An integer menu status constant: to indicate an error condition.
 *   - A string of HTML content.
 *   - A renderable array of content.
 *
 * @see drupal_deliver_page()
 */
function http_handler_deliver_html_page($page_callback_result) {
  // Emit the correct charset HTTP header, but not if the page callback
  // result is null, since that likely indicates that it printed something
  // in which case, no further headers may be sent, and not if code running
  // for this page request has already set the content type header.
  if (isset($page_callback_result) && is_null(drupal_get_http_header('Content-Type'))) {
    drupal_add_http_header('Content-Type', 'text/html; charset=utf-8');
  }

  // Send appropriate HTTP-Header for browsers and search engines.
  global $language;
  drupal_add_http_header('Content-Language', $language->language);

  // By default, do not allow the site to be rendered in an iframe on another
  // domain, but provide a variable to override this. If the code running for
  // this page request already set the X-Frame-Options header earlier, don't
  // overwrite it here.
  $frame_options = variable_get('x_frame_options', 'SAMEORIGIN');
  if ($frame_options && is_null(drupal_get_http_header('X-Frame-Options'))) {
    drupal_add_http_header('X-Frame-Options', $frame_options);
  }

  $default_site_403 = variable_get('site_403', '');

  $q = $_GET['q'];
  switch ($page_callback_result) {
    case HttpStatusCodeEnum::HTTP_BAD_REQUEST:
      drupal_add_http_header('Status', $page_callback_result . ' Bad Request');
      watchdog('bad request', 'drupal_deliver_page error : @query', array('@query' => $q), WATCHDOG_WARNING);

      if (!isset($_GET['destination'])) {
        if (!url_is_external($q)) {
          $_GET['destination'] = $q;
        }
      }

      // Act as 400 in order to use defined page.
      $path = drupal_get_normal_path(variable_get('site_' . $page_callback_result, $default_site_403));
      if ($path && $path != $q) {
        menu_set_active_item($path);
        $return = menu_execute_active_handler($path, FALSE);
      }

      if (empty($return) || $return == MENU_NOT_FOUND || $return == MENU_ACCESS_DENIED) {
        drupal_set_title(t('Bad Request'));
        $return = t('You are not authorized to access this page.');
      }

      echo drupal_render_page($return);

      drupal_page_footer();
      break;

    case HttpStatusCodeEnum::HTTP_UNAUTHORIZED:
      drupal_add_http_header('Status', $page_callback_result . ' Unauthorized');
      watchdog('authentication required', 'drupal_deliver_page error : @query', array('@query' => $q), WATCHDOG_WARNING);

      if (!isset($_GET['destination'])) {
        if (!url_is_external($q)) {
          $_GET['destination'] = $q;
        }
      }

      // Act as 401 in order to use defined page.
      $path = drupal_get_normal_path(variable_get('site_' . $page_callback_result, $default_site_403));
      if ($path && $path != $q) {
        menu_set_active_item($path);
        $return = menu_execute_active_handler($path, FALSE);
      }

      if (empty($return) || $return == MENU_NOT_FOUND || $return == MENU_ACCESS_DENIED) {
        drupal_set_title(t('Access Unauthorized'));
        $return = t('You are not authorized to access this page.');
      }

      echo drupal_render_page($return);

      // Perform end-of-request tasks.
      drupal_page_footer();
      break;

    case HttpStatusCodeEnum::HTTP_METHOD_NOT_ALLOWED:
      drupal_add_http_header('Status', $page_callback_result . ' Method Not Allowed');
      watchdog('method not allowed', 'drupal_deliver_page error : @query', array('@query' => $q), WATCHDOG_WARNING);

      if (!isset($_GET['destination'])) {
        if (!url_is_external($q)) {
          $_GET['destination'] = $q;
        }
      }

      // Act as 405 in order to use defined page.
      $path = drupal_get_normal_path(variable_get('site_' . $page_callback_result, $default_site_403));
      if ($path && $path != $q) {
        menu_set_active_item($path);
        $return = menu_execute_active_handler($path, FALSE);
      }

      if (empty($return) || $return == MENU_NOT_FOUND || $return == MENU_ACCESS_DENIED) {
        drupal_set_title(t('Method Not Allowed'));
        $return = t('You are not authorized to access this page.');
      }

      echo drupal_render_page($return);

      drupal_page_footer();
      break;

    case HttpStatusCodeEnum::HTTP_GONE:
      drupal_add_http_header('Status', $page_callback_result . ' Gone');
      watchdog('gone', 'drupal_deliver_page error : @query', array('@query' => $q), WATCHDOG_WARNING);

      if (!isset($_GET['destination'])) {
        if (!url_is_external($q)) {
          $_GET['destination'] = $q;
        }
      }

      // Act as 410 in order to use defined page.
      $path = drupal_get_normal_path(variable_get('site_' . $page_callback_result, $default_site_403));
      if ($path && $path != $q) {
        menu_set_active_item($path);
        $return = menu_execute_active_handler($path, FALSE);
      }

      if (empty($return) || $return == MENU_NOT_FOUND || $return == MENU_ACCESS_DENIED) {
        drupal_set_title(t('Resource Gone'));
        $return = t('The resource is no longer available and no redirect address is known..');
      }

      echo drupal_render_page($return);

      drupal_page_footer();
      break;

    case HttpStatusCodeEnum::HTTP_NOT_FOUND:
      drupal_deliver_html_page($page_callback_result);
      break;

    case HttpStatusCodeEnum::HTTP_FORBIDDEN:
      // No break.
    case MENU_ACCESS_DENIED:
      if (user_is_anonymous()) {
        http_handler_deliver_html_page(HttpStatusCodeEnum::HTTP_UNAUTHORIZED);
      }
      else {
        drupal_deliver_html_page($page_callback_result);
      }
      break;

    default:
      drupal_deliver_html_page($page_callback_result);
      break;
  }
}