function hreflang_page_attachments in Hreflang 8

Implements hook_page_attachments().

File

./hreflang.module, line 28

Adds hreflang link elements to the header of each page.

Code

function hreflang_page_attachments(array &$page) {

  // No need to add hreflang tags for 404/403 pages.
  if (\Drupal::request()->attributes
    ->has('exception')) {
    return;
  }
  $language_manager = \Drupal::getContainer()
    ->get('language_manager');
  if (!$language_manager
    ->isMultilingual()) {
    return;
  }
  $route = \Drupal::service('path.matcher')
    ->isFrontPage() ? '<front>' : '<current>';
  $links = $language_manager
    ->getLanguageSwitchLinks(LanguageInterface::TYPE_INTERFACE, Url::fromRoute($route));
  if (empty($links->links)) {
    return;
  }
  foreach ($links->links as $langcode => $link) {
    if (!isset($link['query'])) {
      $link['query'] = [];
    }
    $link['query'] += \Drupal::request()->query
      ->all();
    if (isset($link['url'])) {
      $link['url']
        ->setOptions($link);
      $link['url']
        ->setAbsolute();
      $page['#attached']['html_head_link'][] = [
        [
          'rel' => 'alternate',
          'hreflang' => $langcode,
          'href' => $link['url']
            ->toString(),
        ],
        TRUE,
      ];
    }
  }
}