function WorkspaceRepository::loadTree

File

core/modules/workspaces/src/WorkspaceRepository.php, line 53

Class

WorkspaceRepository

Provides the default workspace tree lookup operations.

Namespace

Code

public function loadTree() {
  if (!isset($this->tree)) {
    $cache = $this->cache
      ->get('workspace_tree');
    if ($cache) {
      $this->tree = $cache->data;
      return $this->tree;
    }
    /** @var \Drupal\workspaces\WorkspaceInterface[] $workspaces */
    $workspaces = $this->entityTypeManager
      ->getStorage('workspace')
      ->loadMultiple();
    // First, sort everything alphabetically.
    uasort($workspaces, function (WorkspaceInterface $a, WorkspaceInterface $b) {
      assert(Inspector::assertStringable($a->label()) && Inspector::assertStringable($b->label()), 'Workspace labels are expected to be a string.');
      return strnatcasecmp($a->label(), $b->label());
    });
    $tree_children = [];
    foreach ($workspaces as $workspace_id => $workspace) {
      $tree_children[$workspace->parent->target_id][] = $workspace_id;
    }
    // Keeps track of the parents we have to process, the last entry is used
    // for the next processing step. Top-level (root) workspace use NULL as
    // the parent, so we need to initialize the list with that value.
    $process_parents[] = NULL;
    // Loops over the parent entities and adds its children to the tree array.
    // Uses a loop instead of a recursion, because it's more efficient.
    $tree = [];
    while (count($process_parents)) {
      $parent = array_pop($process_parents);
      if (!empty($tree_children[$parent])) {
        $child_id = current($tree_children[$parent]);
        do {
          if (empty($child_id)) {
            break;

          }
          $tree[$child_id] = $workspaces[$child_id];
          if (!empty($tree_children[$child_id])) {
            // We have to continue with this parent later.
            $process_parents[] = $parent;
            // Use the current entity as parent for the next iteration.
            $process_parents[] = $child_id;
            // Move pointer so that we get the correct entity the next time.
            next($tree_children[$parent]);
            break;

          }
        } while ($child_id = next($tree_children[$parent]));
      }
    }
    // Generate a graph object in order to populate the `_depth`, `_ancestors`
    // and '_descendants' properties for all the entities.
    $graph = [];
    foreach ($workspaces as $workspace_id => $workspace) {
      $graph[$workspace_id]['edges'] = [];
      if (!$workspace->parent
        ->isEmpty()) {
        $graph[$workspace_id]['edges'][$workspace->parent->target_id] = TRUE;
      }
    }
    $graph = (new Graph($graph))->searchAndSort();
    $this->tree = [];
    foreach (array_keys($tree) as $workspace_id) {
      $this->tree[$workspace_id] = [
        'depth' => count($graph[$workspace_id]['paths']),
        'ancestors' => array_keys($graph[$workspace_id]['paths']),
        'descendants' => isset($graph[$workspace_id]['reverse_paths']) ? array_keys($graph[$workspace_id]['reverse_paths']) : [],
      ];
    }
    // Use the 'workspace_list' entity type cache tag because it will be
    // invalidated automatically when a workspace is added, updated or
    // deleted.
    $this->cache
      ->set('workspace_tree', $this->tree, Cache::PERMANENT, $this->entityTypeManager
      ->getDefinition('workspace')
      ->getListCacheTags());
  }
  return $this->tree;
}