Chris@0: <?php
Chris@0: 
Chris@0: namespace Drupal\book;
Chris@0: 
Chris@0: use Drupal\Core\Entity\EntityTypeManagerInterface;
Chris@0: use Drupal\Core\Extension\ModuleUninstallValidatorInterface;
Chris@0: use Drupal\Core\StringTranslation\StringTranslationTrait;
Chris@0: use Drupal\Core\StringTranslation\TranslationInterface;
Chris@0: 
Chris@0: /**
Chris@0:  * Prevents book module from being uninstalled whilst any book nodes exist or
Chris@0:  * there are any book outline stored.
Chris@0:  */
Chris@0: class BookUninstallValidator implements ModuleUninstallValidatorInterface {
Chris@0: 
Chris@0:   use StringTranslationTrait;
Chris@0: 
Chris@0:   /**
Chris@0:    * The book outline storage.
Chris@0:    *
Chris@0:    * @var \Drupal\book\BookOutlineStorageInterface
Chris@0:    */
Chris@0:   protected $bookOutlineStorage;
Chris@0: 
Chris@0:   /**
Chris@0:    * The entity type manager.
Chris@0:    *
Chris@0:    * @var \Drupal\Core\Entity\EntityTypeManagerInterface
Chris@0:    */
Chris@0:   protected $entityTypeManager;
Chris@0: 
Chris@0:   /**
Chris@0:    * Constructs a new BookUninstallValidator.
Chris@0:    *
Chris@0:    * @param \Drupal\book\BookOutlineStorageInterface $book_outline_storage
Chris@0:    *   The book outline storage.
Chris@0:    * @param \Drupal\Core\Entity\EntityTypeManagerInterface $entity_type_manager
Chris@0:    *   The entity type manager.
Chris@0:    * @param \Drupal\Core\StringTranslation\TranslationInterface $string_translation
Chris@0:    *   The string translation service.
Chris@0:    */
Chris@0:   public function __construct(BookOutlineStorageInterface $book_outline_storage, EntityTypeManagerInterface $entity_type_manager, TranslationInterface $string_translation) {
Chris@0:     $this->bookOutlineStorage = $book_outline_storage;
Chris@0:     $this->entityTypeManager = $entity_type_manager;
Chris@0:     $this->stringTranslation = $string_translation;
Chris@0:   }
Chris@0: 
Chris@0:   /**
Chris@0:    * {@inheritdoc}
Chris@0:    */
Chris@0:   public function validate($module) {
Chris@0:     $reasons = [];
Chris@0:     if ($module == 'book') {
Chris@0:       if ($this->hasBookOutlines()) {
Chris@0:         $reasons[] = $this->t('To uninstall Book, delete all content that is part of a book');
Chris@0:       }
Chris@0:       else {
Chris@0:         // The book node type is provided by the Book module. Prevent uninstall
Chris@0:         // if there are any nodes of that type.
Chris@0:         if ($this->hasBookNodes()) {
Chris@0:           $reasons[] = $this->t('To uninstall Book, delete all content that has the Book content type');
Chris@0:         }
Chris@0:       }
Chris@0:     }
Chris@0:     return $reasons;
Chris@0:   }
Chris@0: 
Chris@0:   /**
Chris@0:    * Checks if there are any books in an outline.
Chris@0:    *
Chris@0:    * @return bool
Chris@0:    *   TRUE if there are books, FALSE if not.
Chris@0:    */
Chris@0:   protected function hasBookOutlines() {
Chris@0:     return $this->bookOutlineStorage->hasBooks();
Chris@0:   }
Chris@0: 
Chris@0:   /**
Chris@0:    * Determines if there is any book nodes or not.
Chris@0:    *
Chris@0:    * @return bool
Chris@0:    *   TRUE if there are book nodes, FALSE otherwise.
Chris@0:    */
Chris@0:   protected function hasBookNodes() {
Chris@0:     $nodes = $this->entityTypeManager->getStorage('node')->getQuery()
Chris@0:       ->condition('type', 'book')
Chris@0:       ->accessCheck(FALSE)
Chris@0:       ->range(0, 1)
Chris@0:       ->execute();
Chris@0:     return !empty($nodes);
Chris@0:   }
Chris@0: 
Chris@0: }