registry = $registry; } /** * Page block html topmenu gethtml before * * @param \Magento\Framework\Event\Observer $observer * @return void * @SuppressWarnings(PHPMD.UnusedFormalParameter) */ public function execute(\Magento\Framework\Event\Observer $observer) { $post = $this->registry->registry('current_blog_post'); if ($post && $post->getIsPreviewMode()) { $layout = $observer->getLayout(); $layout->getUpdate()->addHandle('blog_non_cacheable'); } } }