If I have some nodes that are of type book, how can I go through them in a php script and tell which is the root? thanks

  • 1
    can you elaborate your question? Feb 11, 2017 at 6:16

1 Answer 1


You can try to build the menu tree for your book. Book nodes do not have direct parents. The relationship is defined by the menu structure.

This will give you the structure of the book menu.

$book = $node->book;
$tree = menu_tree_all_data(book_menu_name($book['bid']));
  • I got this error Error: Call to undefined function book_menu_name()
    – Diana
    Feb 13, 2017 at 14:59
  • This function is part of the book.module file. It should be available after Drupal bootstrapped. Where exactly are you putting your code?
    – schlicki
    Feb 13, 2017 at 16:27

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