public function eventBeforeDelete()
    {
        // delete all attached sub blocks
        $this->deleteAllSubBlocks($this->id);
        //save block data for afterDeleteEvent
        $this->_olds = $this->getOldAttributes();
        // verify if the block exists or not
        $class = ($this->block) ? $this->block->getNameForLog() : '[class has been removed from the filesystem]';
        // log event
        Log::add(3, ['tableName' => 'cms_nav_item_page_block_item', 'action' => 'delete', 'row' => $this->id, 'pageTitle' => $this->droppedPageTitle, 'blockName' => $class], 'cms_nav_item_page_block_item', $this->id);
    }