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

public BookAdminEditForm::__construct(EntityStorageInterface

book_node_view(array &$build, EntityInterface $node, EntityViewDisplayInterface $display, $view_mode) Implements

The book outline storage. Type:

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

The book manager. Type:

public BookManager::bookTreeOutput(array $tree)

protected BookManager::addParentSelectFormElements(array $book_link)

public BookManager::loadBookLink($nid, $translate = TRUE)

public BookManagerInterface::bookTreeOutput(array $tree)