drupal/core/modules/toolbar/toolbar.module

<?php

/**
 * @file
 * Administration toolbar for quick access to top level administration items.
 */

use Drupal\Core\Cache\Cache;
use Drupal\Core\Menu\MenuTreeParameters;
use Drupal\Core\Render\Element;
use Drupal\Core\Routing\RouteMatchInterface;
use Drupal\Core\Template\Attribute;
use Drupal\Component\Datetime\DateTimePlus;
use Drupal\Component\Utility\Crypt;
use Drupal\Component\Utility\String;
use Drupal\user\Entity\Role;
use Drupal\Core\Url;

/**
 * Implements hook_help().
 */
function toolbar_help($route_name, RouteMatchInterface $route_match) {
  switch ($route_name) {
    case 'help.page.toolbar':
      $output = '<h3>' . t('About') . '</h3>';
      $output .= '<p>' . t('The Toolbar module provides a toolbar for site administrators, which displays tabs and trays provided by the Toolbar module itself and other modules. For more information, see the <a href="!toolbar_docs">online documentation for the Toolbar module</a>.', array('!toolbar_docs' => 'https://drupal.org/documentation/modules/toolbar')) . '</p>';
      $output .= '<h4>' . t('Terminology') . '</h4>';
      $output .= '<dl>';
      $output .= '<dt>' . t('Tabs') . '</dt>';
      $output .= '<dd>' . t('Tabs are buttons, displayed in a bar across the top of the screen. Some tabs execute an action (such as starting Edit mode), while other tabs toggle which tray is open.') . '</dd>';
      $output .= '<dt>' . t('Trays') . '</dt>';
      $output .= '<dd>' . t('Trays are usually lists of links, which can be hierarchical like a menu. If a tray has been toggled open, it is displayed either vertically or horizontally below the tab bar, depending on the browser width. Only one tray may be open at a time. If you click another tab, that tray will replace the tray being displayed. In wide browser widths, the user has the ability to toggle from vertical to horizontal, using a link at the bottom or right of the tray. Hierarchical menus only have open/close behavior in vertical mode; if you display a tray containing a hierarchical menu horizontally, only the top-level links will be available.') . '</dd>';
      $output .= '</dl>';
      return $output;
  }
}

/**
 * Implements hook_theme().
 */
function toolbar_theme($existing, $type, $theme, $path) {
  $items['toolbar'] = array(
    'render element' => 'element',
  );

  return $items;
}

/**
 * Implements hook_page_top().
 *
 * Add admin toolbar to the top of the page automatically.
 */
function toolbar_page_top(array &$page_top) {
  $page_top['toolbar'] = array(
    '#type' => 'toolbar',
    '#access' => \Drupal::currentUser()->hasPermission('access toolbar'),
  );
}

/**
 * Prepares variables for administration toolbar templates.
 *
 * Default template: toolbar.html.twig.
 *
 * @param array $variables
 *   An associative array containing:
 *   - element: An associative array containing the properties and children of
 *     the tray. Properties used: #children, #attributes and #bar.
 */
function template_preprocess_toolbar(&$variables) {
  $element = $variables['element'];

  // Prepare the toolbar attributes.
  $variables['attributes'] = $element['#attributes'];
  $variables['toolbar_attributes'] = new Attribute($element['#bar']['#attributes']);
  $variables['toolbar_heading'] = $element['#bar']['#heading'];

  // Prepare the trays and tabs for each toolbar item as well as the remainder
  // variable that will hold any non-tray, non-tab elements.
  $variables['trays'] = array();
  $variables['tabs'] = array();
  $variables['remainder'] = array();
  foreach (Element::children($element) as $key) {
    // Add the tray.
    if (isset($element[$key]['tray'])) {
      $variables['trays'][$key] = array(
        'links' => $element[$key]['tray'],
        'attributes' => new Attribute($element[$key]['tray']['#wrapper_attributes']),
      );
      if (array_key_exists('#heading', $element[$key]['tray'])) {
        $variables['trays'][$key]['label'] = $element[$key]['tray']['#heading'];
      }
    }

    $attributes = array();
    // Pass the wrapper attributes along.
    if (array_key_exists('#wrapper_attributes', $element[$key])) {
      $attributes = $element[$key]['#wrapper_attributes'];
    }

    // Add the tab.
    $variables['tabs'][$key] = array(
      'link' => $element[$key]['tab'],
      'attributes' => new Attribute($attributes),
    );

    // Add other non-tray, non-tab child elements to the remainder variable for
    // later rendering.
    foreach (Element::children($element[$key]) as $child_key) {
      if (!in_array($child_key, array('tray', 'tab'))) {
        $variables['remainder'][$key][$child_key] = $element[$key][$child_key];
      }
    }
  }
}

/**
 * Implements hook_toolbar().
 */
function toolbar_toolbar() {
  // The 'Home' tab is a simple link, with no corresponding tray.
  $items['home'] = array(
    '#type' => 'toolbar_item',
    'tab' => array(
      '#type' => 'link',
      '#title' => t('Back to site'),
      '#url' => Url::fromRoute('<front>'),
      '#attributes' => array(
        'title' => t('Return to site content'),
        'class' => array('toolbar-icon', 'toolbar-icon-escape-admin'),
        'data-toolbar-escape-admin' => TRUE,
      ),
    ),
    '#wrapper_attributes' => array(
      'class' => array('hidden'),
    ),
    '#attached' => array(
      'library' => array(
        'toolbar/toolbar.escapeAdmin',
      ),
    ),
    '#weight' => -20,
  );

  // To conserve bandwidth, we only include the top-level links in the HTML.
  // The subtrees are fetched through a JSONP script that is generated at the
  // toolbar_subtrees route. We provide the JavaScript requesting that JSONP
  // script here with the hash parameter that is needed for that route.
  // @see toolbar_subtrees_jsonp()
  $langcode = \Drupal::languageManager()->getCurrentLanguage()->getId();
  $subtrees_attached['js'][] = array(
    'type' => 'setting',
    'data' => array('toolbar' => array(
      'subtreesHash' => _toolbar_get_subtrees_hash($langcode),
      'langcode' => $langcode,
    )),
  );

  // The administration element has a link that is themed to correspond to
  // a toolbar tray. The tray contains the full administrative menu of the site.
  $items['administration'] = array(
    '#type' => 'toolbar_item',
    'tab' => array(
      '#type' => 'link',
      '#title' => t('Manage'),
      '#url' => Url::fromRoute('system.admin'),
      '#attributes' => array(
        'title' => t('Admin menu'),
        'class' => array('toolbar-icon', 'toolbar-icon-menu'),
        // A data attribute that indicates to the client to defer loading of
        // the admin menu subtrees until this tab is activated. Admin menu
        // subtrees will not render to the DOM if this attribute is removed.
        // The value of the attribute is intentionally left blank. Only the
        // presence of the attribute is necessary.
        'data-drupal-subtrees' => '',
      ),
    ),
    'tray' => array(
      '#heading' => t('Administration menu'),
      '#attached' => $subtrees_attached,
      'toolbar_administration' => array(
        '#pre_render' => array(
          'toolbar_prerender_toolbar_administration_tray',
        ),
        '#type' => 'container',
        '#attributes' => array(
          'class' => array('toolbar-menu-administration'),
        ),
      ),
    ),
    '#weight' => -15,
  );

  return $items;
}

/**
 * Renders the toolbar's administration tray.
 *
 * @param array $element
 *   A renderable array.
 *
 * @return array
 *   The updated renderable array.
 *
 * @see drupal_render()
 */
function toolbar_prerender_toolbar_administration_tray(array $element) {
  $menu_tree = \Drupal::menuTree();
  // Render the top-level administration menu links.
  $parameters = new MenuTreeParameters();
  $parameters->setRoot('system.admin')->excludeRoot()->setTopLevelOnly()->onlyEnabledLinks();
  $tree = $menu_tree->load(NULL, $parameters);
  $manipulators = array(
    array('callable' => 'menu.default_tree_manipulators:checkAccess'),
    array('callable' => 'menu.default_tree_manipulators:generateIndexAndSort'),
    array('callable' => 'toolbar_menu_navigation_links'),
  );
  $tree = $menu_tree->transform($tree, $manipulators);
  $element['administration_menu'] = $menu_tree->build($tree);
  return $element;
}

/**
 * Adds toolbar-specific attributes to the menu link tree.
 *
 * @param \Drupal\Core\Menu\MenuLinkTreeElement[] $tree
 *   The menu link tree to manipulate.
 *
 * @return \Drupal\Core\Menu\MenuLinkTreeElement[]
 *   The manipulated menu link tree.
 */
function toolbar_menu_navigation_links(array $tree) {
  foreach ($tree as $element) {
    if ($element->subtree) {
      toolbar_menu_navigation_links($element->subtree);
    }

    // Make sure we have a path specific ID in place, so we can attach icons
    // and behaviors to the menu links.
    $link = $element->link;
    $url = $link->getUrlObject();
    if ($url->isExternal()) {
      // This is an unusual case, so just get a distinct, safe string.
      $id = substr(Crypt::hashBase64($url->getUri()), 0, 16);
    }
    else {
      $id = str_replace(array('.', '<', '>'), array('-', '', ''), $url->getRouteName());
    }

    // Get the non-localized title to make the icon class.
    $definition = $link->getPluginDefinition();

    $element->options['attributes']['id'] = 'toolbar-link-' . $id;
    $element->options['attributes']['class'][] = 'toolbar-icon';
    $element->options['attributes']['class'][] = 'toolbar-icon-' . strtolower(str_replace(array('.', ' ', '_'), array('-', '-', '-'), $definition['id']));
    $element->options['attributes']['title'] = String::checkPlain($link->getDescription());
  }
  return $tree;
}

/**
 * Returns the rendered subtree of each top-level toolbar link.
 */
function toolbar_get_rendered_subtrees() {
  $menu_tree = \Drupal::menuTree();
  $parameters = new MenuTreeParameters();
  $parameters->setRoot('system.admin')->excludeRoot()->setMaxDepth(3)->onlyEnabledLinks();
  $tree = $menu_tree->load(NULL, $parameters);
  $manipulators = array(
    array('callable' => 'menu.default_tree_manipulators:checkAccess'),
    array('callable' => 'menu.default_tree_manipulators:generateIndexAndSort'),
    array('callable' => 'toolbar_menu_navigation_links'),
  );
  $tree = $menu_tree->transform($tree, $manipulators);
  $subtrees = array();
  foreach ($tree as $element) {
    /** @var \Drupal\Core\Menu\MenuLinkInterface $link */
    $link = $element->link;
    if ($element->subtree) {
      $subtree = $menu_tree->build($element->subtree);
      $output = drupal_render($subtree);
    }
    else {
      $output = '';
    }
    // Many routes have dots as route name, while some special ones like <front>
    // have <> characters in them.
    $id = str_replace(array('.', '<', '>'), array('-', '', '' ), $link->getUrlObject()->getRouteName());

    $subtrees[$id] = $output;
  }
  return $subtrees;
}

/**
 * Returns the hash of the per-user rendered toolbar subtrees.
 *
 * @param string $langcode
 *   The langcode of the current request.
 *
 * @return string
 *   The hash of the admin_menu subtrees.
 */
function _toolbar_get_subtrees_hash($langcode) {
  $uid = \Drupal::currentUser()->id();
  $cid = _toolbar_get_user_cid($uid, $langcode);
  if ($cache = \Drupal::cache('toolbar')->get($cid)) {
    $hash = $cache->data;
  }
  else {
    $subtrees = toolbar_get_rendered_subtrees();
    $hash = Crypt::hashBase64(serialize($subtrees));
    // Cache using a tag 'user' so that we can invalidate all user-specific
    // caches later, based on the user's ID regardless of language.
    // Clear the cache when the 'locale' tag is deleted. This ensures a fresh
    // subtrees rendering when string translations are made.
    $role_list_cache_tags = \Drupal::entityManager()->getDefinition('user_role')->getListCacheTags();
    \Drupal::cache('toolbar')->set($cid, $hash, Cache::PERMANENT, Cache::mergeTags(array('user:' . $uid, 'locale', 'menu:admin'), $role_list_cache_tags));
  }
  return $hash;
}

/**
 * Returns a cache ID from the user and language IDs.
 *
 * @param int $uid
 *   A user ID.
 * @param string $langcode
 *   The langcode of the current request.
 *
 * @return string
 *   A unique cache ID for the user.
 */
function _toolbar_get_user_cid($uid, $langcode) {
  return 'toolbar_' . $uid . ':' . $langcode;
}