/**
* {@inheritdoc}
*/
public function getCacheKeys()
{
// Add a key for the active book trail.
$current_bid = 0;
if ($node = $this->requestStack->getCurrentRequest()->get('node')) {
$current_bid = empty($node->book['bid']) ? 0 : $node->book['bid'];
}
if ($current_bid === 0) {
return parent::getCacheKeys();
}
$active_trail = $this->bookManager->getActiveTrailIds($node->book['bid'], $node->book);
$active_trail_key = 'trail.' . implode('|', $active_trail);
return array_merge(parent::getCacheKeys(), array($active_trail_key));
}
