protected BookManager::buildBookOutlineRecursive(&$links, $parents,

public BookOutline::childrenLinks(array $book_link)

public BookOutlineStorage::getChildRelativeDepth($book_link

public BookAdminEditForm::__construct(EntityStorageInterface

public BookRemoveForm::submitForm(array &$form, FormStateInterface

public BookNavigationCacheContext::

public BookManagerInterface::getActiveTrailIds($bid, $link)

protected BookExport::bookNodeExport(NodeInterface $node, $children = '')

public BookRemoveForm::__construct(BookManagerInterface $boo

Prevents book module from being uninstalled whilst any book nodes exist or there are any book outline stored. Hierarchy