MenuTreeStorage::setParents

protected MenuTreeStorage::setParents(array &$fields, $parent, array $original)

protected function setParents(array &$fields, $parent, array $original) {
  // Directly fill parents for top-level links.
  if (empty($fields['parent'])) {
    $fields['p1'] = $fields['mlid'];
    for ($i = 2; $i <= $this->maxDepth(); $i++) {
      $fields["p$i"] = 0;
    }
    $fields['depth'] = 1;
  }
  // Otherwise, ensure that this link's depth is not beyond the maximum depth
  // and fill parents based on the parent link.
  else {
    // @todo We want to also check $original['has_children'] here, but that
    //   will be 0 even if there are children if those are not enabled.
    //   has_children is really just the rendering hint. So, we either need
    //   to define another column (has_any_children), or do the extra query.
    //   https://www.drupal.org/node/2302149
    if ($original) {
      $limit = $this->maxDepth() - $this->doFindChildrenRelativeDepth($original) - 1;
    }
    else {
      $limit = $this->maxDepth() - 1;
    }
    if ($parent['depth'] > $limit) {
      throw new PluginException("The link with ID {$fields['id']} or its children exceeded the maximum depth of {$this->maxDepth()}");
    }
    $fields['depth'] = $parent['depth'] + 1;
    $i = 1;
    while ($i < $fields['depth']) {
      $p = 'p' . $i++;
      $fields[$p] = $parent[$p];
    }
    $p = 'p' . $i++;
    // The parent (p1 - p9) corresponding to the depth always equals the mlid.
    $fields[$p] = $fields['mlid'];
    while ($i <= static::MAX_DEPTH) {
      $p = 'p' . $i++;
      $fields[$p] = 0;
    }
  }
}