Feature: #99312 - PSR-14 Event for fetching YouTube/Vimeo preview image 

Description 

A new PSR-14 event \TYPO3\CMS\Core\Resource\OnlineMedia\Event\AfterVideoPreviewFetchedEvent has been introduced. The purpose of this event is to modify the preview file of online media previews (like YouTube and Vimeo). If, for example, a processed file is bad (blank or outdated), this event can be used to modify and/or update the preview file.

The event features the following methods:

• getFile(): Returns the \TYPO3\CMS\Core\Resource\File in question
• getOnlineMediaId(): Returns the video ID
• getPreviewImageFilename(): Returns the filename of the preview image
• setPreviewImageFilename(): Set the filename for the preview image

Registration of the event in your extension's Services.yaml:

MyVendor\MyExtension\EventListener\ExampleEventListener:
    tags:
      - name: event.listener
        identifier: 'exampleEventListener'

The corresponding event listener class:

namespace MyVendor\MyExtension\EventListener;

use TYPO3\CMS\Core\Resource\OnlineMedia\Event\AfterVideoPreviewFetchedEvent;

final class ExampleEventListener
{
    public function __invoke(AfterVideoPreviewFetchedEvent $event): void
    {
        $event->setPreviewImageFilename(
            '/var/www/websites/typo3temp/assets/online_media/new-preview-image.jpg'
        );
        // An extension could use this to fetch new images again.
    }
}

Impact 

It is now possible to change the filename for the preview image of a YouTube or Vimeo thumbnail image.