/**
* Generates HTML for export when invoked by book_export().
*
* The given node is embedded to its absolute depth in a top level section. For
* example, a child node with depth 2 in the hierarchy is contained in
* (otherwise empty) <div> elements corresponding to depth 0 and depth 1.
* This is intended to support WYSIWYG output - e.g., level 3 sections always
* look like level 3 sections, no matter their depth relative to the node
* selected to be exported as printer-friendly HTML.
*
* @param \Drupal\node\NodeInterface $node
* The node to export.
*
* @throws \Exception
* Thrown when the node was not attached to a book.
*
* @return array
* A render array representing the HTML for a node and its children in the
* book hierarchy.
*/
public function bookExportHtml(NodeInterface $node)
{
if (!isset($node->book)) {
throw new \Exception();
}
$tree = $this->bookManager->bookSubtreeData($node->book);
$contents = $this->exportTraverse($tree, array($this, 'bookNodeExport'));
return array('#theme' => 'book_export_html', '#title' => $node->label(), '#contents' => $contents, '#depth' => $node->book['depth'], '#cache' => ['tags' => $node->getEntityType()->getListCacheTags()]);
}
/**
* Gets a list of node revision IDs for a specific node.
*
* @param \Drupal\node\NodeInterface
* The node entity.
* @param \Drupal\node\NodeStorageInterface $node_storage
* The node storage handler.
*
* @return int[]
* Node revision IDs (in descending order).
*/
protected function _getRevisionIds(NodeInterface $node, NodeStorageInterface $node_storage)
{
$result = $node_storage->getQuery()->allRevisions()->condition($node->getEntityType()->getKey('id'), $node->id())->sort($node->getEntityType()->getKey('revision'), 'DESC')->pager(50)->execute();
return array_keys($result);
}
