public function deletePhotoAction()
 {
     $book = $this->_getBook();
     if (isset($book) && is_object($book)) {
         $this->view->viewer = $viewer = Engine_Api::_()->user()->getViewer();
         $authors = $book->getAuthors();
         $allowDelete = false;
         if ($viewer->isAdmin() || $viewer->getIdentity() != $book->user_id) {
             $allowDelete = true;
         } else {
             foreach ($authors as $author) {
                 if ($viewer->isSelf($author)) {
                     $allowDelete = true;
                 }
             }
         }
         if ($allowDelete) {
             $photoId = $this->_getParam('photo_id');
             if ($photoId) {
                 $db = Engine_Db_Table::getDefaultAdapter();
                 $db->beginTransaction();
                 try {
                     $photoTbl = new Book_Model_DbTable_Photos();
                     $select = $photoTbl->select()->where("photo_id = ?", $photoId);
                     $photo = $photoTbl->fetchRow($select);
                     $photo->delete();
                     $db->commit();
                 } catch (Exception $e) {
                     $db->rollBack();
                     throw $e;
                 }
                 $this->view->status = 1;
                 $this->view->message = Zend_Registry::get('Zend_Translate')->_('The photo is deleted successfully !');
             }
         }
     }
 }