Feature: #108462 - Add PSR-14 Event AfterPageContentPreviewRenderedEvent 

Description 

The class \TYPO3\CMS\Backend\View\BackendLayout\Grid\GridColumnItem is the central entity to generate various previews of content elements.

Developers can either use the event \TYPO3\CMS\Backend\View\Event\PageContentPreviewRenderingEvent to generate a preview or implementing \TYPO3\CMS\Backend\Preview\PreviewRendererInterface .

The new PSR-14 event \TYPO3\CMS\Backend\View\Event\AfterPageContentPreviewRenderedEvent can now be used to enrich the output generated by one of those.

Example 

An example event listener could look like this:

namespace MyVendor\MyExtension\EventListener;

use TYPO3\CMS\Backend\View\Event\AfterPageContentPreviewRenderedEvent;
use TYPO3\CMS\Core\Attribute\AsEventListener;

#[AsEventListener('my-extension')]
final class AfterPageContentPreviewRenderedEventListener
{
    public function __invoke(AfterPageContentPreviewRenderedEvent $event): void
    {
        $content = 'before<hr />'. $event->getPreviewContent() . '<hr />after';
        $event->setPreviewContent($content);
    }
}

Impact 

As integrator it is sometimes handy to enrich the previews of other content elements and plugins to display additional fields.