class TermStorageController

class TermStorageController extends DatabaseStorageControllerNG {

  /**
   * Overrides Drupal\Core\Entity\DatabaseStorageController::create().
   *
   * @param array $values
   *   An array of values to set, keyed by property name. A value for the
   *   vocabulary ID ('vid') is required.
   */
  public function create(array $values) {

    // Save new terms with no parents by default.
    if (empty($values['parent'])) {
      $values['parent'] = array(
        0,
      );
    }
    $entity = parent::create($values);
    return $entity;
  }

  /**
   * Overrides Drupal\Core\Entity\DatabaseStorageController::buildPropertyQuery().
   */
  protected function buildPropertyQuery(QueryInterface $entity_query, array $values) {
    if (isset($values['name'])) {
      $entity_query
        ->condition('name', $values['name'], 'LIKE');
      unset($values['name']);
    }
    parent::buildPropertyQuery($entity_query, $values);
  }

  /**
   * Overrides Drupal\Core\Entity\DatabaseStorageController::postDelete().
   */
  protected function postDelete($entities) {

    // See if any of the term's children are about to be become orphans.
    $orphans = array();
    foreach (array_keys($entities) as $tid) {
      if ($children = taxonomy_term_load_children($tid)) {
        foreach ($children as $child) {

          // If the term has multiple parents, we don't delete it.
          $parents = taxonomy_term_load_parents($child
            ->id());

          // Because the parent has already been deleted, the parent count might
          // be 0.
          if (count($parents) <= 1) {
            $orphans[] = $child
              ->id();
          }
        }
      }
    }

    // Delete term hierarchy information after looking up orphans but before
    // deleting them so that their children/parent information is consistent.
    db_delete('taxonomy_term_hierarchy')
      ->condition('tid', array_keys($entities))
      ->execute();
    if (!empty($orphans)) {
      entity_delete_multiple('taxonomy_term', $orphans);
    }
  }

  /**
   * Overrides Drupal\Core\Entity\DatabaseStorageController::postSave().
   */
  protected function postSave(EntityInterface $entity, $update) {

    // Only change the parents if a value is set, keep the existing values if
    // not.
    if (isset($entity->parent->value)) {
      db_delete('taxonomy_term_hierarchy')
        ->condition('tid', $entity
        ->id())
        ->execute();
      $query = db_insert('taxonomy_term_hierarchy')
        ->fields(array(
        'tid',
        'parent',
      ));
      foreach ($entity->parent as $parent) {
        $query
          ->values(array(
          'tid' => $entity
            ->id(),
          'parent' => (int) $parent->value,
        ));
      }
      $query
        ->execute();
    }
  }

  /**
   * Overrides Drupal\Core\Entity\DatabaseStorageController::resetCache().
   */
  public function resetCache(array $ids = NULL) {
    drupal_static_reset('taxonomy_term_count_nodes');
    drupal_static_reset('taxonomy_get_tree');
    drupal_static_reset('taxonomy_get_tree:parents');
    drupal_static_reset('taxonomy_get_tree:terms');
    drupal_static_reset('taxonomy_term_load_parents');
    drupal_static_reset('taxonomy_term_load_parents_all');
    drupal_static_reset('taxonomy_term_load_children');
    parent::resetCache($ids);
  }

  /**
   * Overrides \Drupal\Core\Entity\DatabaseStorageControllerNG::baseFieldDefintions().
   */
  public function baseFieldDefinitions() {
    $properties['tid'] = array(
      'label' => t('Term ID'),
      'description' => t('The term ID.'),
      'type' => 'integer_field',
      'read-only' => TRUE,
    );
    $properties['uuid'] = array(
      'label' => t('UUID'),
      'description' => t('The term UUID.'),
      'type' => 'string_field',
      'read-only' => TRUE,
    );
    $properties['vid'] = array(
      'label' => t('Vocabulary ID'),
      'description' => t('The ID of the vocabulary to which the term is assigned.'),
      'type' => 'string_field',
    );
    $properties['langcode'] = array(
      'label' => t('Language code'),
      'description' => t('The term language code.'),
      'type' => 'language_field',
    );
    $properties['name'] = array(
      'label' => t('Name'),
      'description' => t('The term name.'),
      'type' => 'string_field',
    );
    $properties['description'] = array(
      'label' => t('Description'),
      'description' => t('A description of the term'),
      'type' => 'string_field',
    );

    // @todo Combine with description.
    $properties['format'] = array(
      'label' => t('Description format'),
      'description' => t('The filter format ID of the description.'),
      'type' => 'string_field',
    );
    $properties['weight'] = array(
      'label' => t('Weight'),
      'description' => t('The weight of this term in relation to other terms.'),
      'type' => 'integer_field',
    );
    $properties['parent'] = array(
      'label' => t('Term Parents'),
      'description' => t('The parents of this term.'),
      'type' => 'integer_field',
      'computed' => TRUE,
    );
    return $properties;
  }

}