function LanguageBlock::build

Builds and returns the renderable array for this block plugin.

If a block should not be rendered because it has no content, then this method must also ensure to return no content: it must then only return an empty array, or an empty array with #cache set (with cacheability metadata indicating the circumstances for it being empty).

Return value

array A renderable array representing the content of the block.

Overrides BlockPluginInterface::build

File

core/modules/language/src/Plugin/Block/LanguageBlock.php, line 88

Class

LanguageBlock

Provides a 'Language switcher' block.

Namespace

Code

public function build() {
  $build = [];
  $type = $this->getDerivativeId();
  $route_match = \Drupal::routeMatch();
  // If there is no route match, for example when creating blocks on 404 pages
  // for logged-in users with big_pipe enabled using the front page instead.
  if ($this->pathMatcher
    ->isFrontPage() || !$route_match->getRouteObject()) {
    // We are skipping the route match on both 404 and front page.
    // Example: If on front page, there is no route match like when creating
    // blocks on 404 pages for logged-in users with big_pipe enabled, use the
    // front page.
    $url = Url::fromRoute('<front>');
  }
  else {
    $url = Url::fromRouteMatch($route_match);
  }
  $links = $this->languageManager
    ->getLanguageSwitchLinks($type, $url);
  // In any render cache items wrapping this block, account for variations
  // by user access to each switcher link, the current path and query
  // arguments, and language negotiation.
  $cache_metadata = BubbleableMetadata::createFromRenderArray($build)->addCacheContexts([
    'url.path',
    'url.query_args',
    'url.site',
    'languages:' . $type,
  ]);
  if (isset($links->links)) {
    $build = [
      '#theme' => 'links__language_block',
      '#links' => $links->links,
      '#attributes' => [
        'class' => [
          "language-switcher-{$links->method_id}",
        ],
      ],
      '#set_active_class' => TRUE,
    ];
    foreach ($links->links as $link) {
      if ($link['url'] instanceof Url) {
        $cache_metadata->addCacheableDependency($link['url']->access(NULL, TRUE));
      }
    }
  }
  $cache_metadata->applyTo($build);
  return $build;
}