Add Language Switcher on admin toolbar

Question

What is the correct way for adding Language Switcher (Dropdown) or links on the admin toolbar menu from my custom module or from a contributed module?

Answer 1

Well, I got something up and running via hook_toolbar. Only thing left is, that you can't click directly on the "Language: EN" string in the toolbar. You have to click slightly next to it. Maybe you can fix this.

Apart from that, please also have a look at the Devel module and their implementation of hook_toolbar where they have an extra src/ToolbarHandler.php class for everything. You better should rebuild the code below into a dedicated handler.

---

use Drupal\Core\Url;
use Drupal\Core\Link;

/**
 * Implements hook_toolbar().
 */
function MYMODULE_toolbar() {

  // Get languages, get current route.
  $current_language = \Drupal::languageManager()->getCurrentLanguage()->getId();
  $languages = \Drupal::languageManager()->getLanguages();
  $route = \Drupal::service('path.matcher')
    ->isFrontPage() ? '<front>' : '<current>';

  // Get links.
  $links = [];
  foreach ($languages as $language) {
    $url = new Url($route, [], ['language' => $language]);
    $links[] = [
      '#markup' => Link::fromTextAndUrl($language->getName(), $url)
        ->toString(),
    ];
  }

  // Set cache.
  $items['admin_toolbar_langswitch'] = [
    '#cache' => [
      'contexts' => [
        'languages:language_interface',
        'url',
      ],
    ],
  ];

  // Build toolbar item and tray.
  $items['admin_toolbar_langswitch'] += [
    '#type'   => 'toolbar_item',
    '#weight' => 999,
    'tab'     => [
      '#type'       => 'html_tag',
      '#tag'        => 'div',
      '#value'      => '<span>' . t('Language') . '</span>: <span class="current-language">' . strtoupper($current_language) . '</span>',
      '#attributes' => [
        'class' => ['toolbar-item-admin-toolbar-langswitch'],
        'title' => t('Admin Toolbar Langswitch'),
      ],
    ],
    'tray'    => [
      '#heading' => t('Admin Toolbar Langswitch'),
      'content'  => [
        '#theme'      => 'item_list',
        '#items'      => $links,
        '#attributes' => [
          'class' => ['toolbar-menu'],
        ],
      ],
    ],
  ];

  return $items;
}

Answer 2

The example above for hook_toolbar is almost perfect. I fixed it, see code below. You just have to remove the span on the Language : EN then the click functionality works perfectly.

see my code:

/**
 * Implements hook_toolbar().
 */
function examplemodule_toolbar() {

  // Get languages, get current route.
  $current_language = \Drupal::languageManager()->getCurrentLanguage()->getId();
  $languages = \Drupal::languageManager()->getLanguages();
  $route = \Drupal::service('path.matcher')
    ->isFrontPage() ? '<front>' : '<current>';

  // Get links.
  $links = [];
  foreach ($languages as $language) {
    $url = new Url($route, [], ['language' => $language]);
    $links[] = [
      '#markup' => Link::fromTextAndUrl($language->getName(), $url)
        ->toString(),
    ];
  }

  // Set cache.
  $items['admin_toolbar_langswitch'] = [
    '#cache' => [
      'contexts' => [
        'languages:language_interface',
        'url',
      ],
    ],
  ];

  // Build toolbar item and tray.
  $items['admin_toolbar_langswitch'] += [
    '#type'   => 'toolbar_item',
    '#weight' => 999,
    'tab'     => [
      '#type'       => 'html_tag',
      '#tag'        => 'div',
      '#value'      => t('Language') . ': ' . strtoupper($current_language),
      '#attributes' => [
        'class' => ['toolbar-item-admin-toolbar-langswitch'],
        'title' => t('Admin Toolbar Langswitch'),
      ],
    ],
    'tray'    => [
      '#heading' => t('Admin Toolbar Langswitch'),
      'content'  => [
        '#theme'      => 'item_list',
        '#items'      => $links,
        '#attributes' => [
          'class' => ['toolbar-menu'],
        ],
      ],
    ],
  ];

  return $items;
}

Answer 3

The link in the reply berramou posted doesn't mention the contrib module toolbar_menu, which makes adding stuff in the toolbar more convenient than what is mentioned in the link.