Gets child relative depth.

Parameters

array $book_link: The book link.

int $max_depth: The maximum supported depth of the book tree.

Return value

int The depth of the searched book.

Overrides BookOutlineStorageInterface::getChildRelativeDepth

File

core/modules/book/src/BookOutlineStorage.php, line 61

Class

BookOutlineStorage

Defines a storage class for books outline.

Namespace

Drupal\book

Code

public function getChildRelativeDepth($book_link, $max_depth) {
  $query = $this->connection
    ->select('book');
  $query->addField('book', 'depth');
  $query->condition('bid', $book_link['bid']);
  $query->orderBy('depth', 'DESC');
  $query->range(0, 1);
  $i = 1;
  $p = 'p1';
  while ($i <= $max_depth && $book_link[$p]) {
    $query->condition($p, $book_link[$p]);
    $p = 'p' . ++$i;
  }
  return $query->execute()
    ->fetchField();
}

---