File renderers for the file abstraction layer (FAL) 

Register a file renderer with #[AsFileRenderer] 

A file renderer implements FileRendererInterface and is registered with the PHP attribute AsFileRenderer . This renderer embeds PDF files in an <iframe> :

<?php

declare(strict_types=1);

namespace MyVendor\MyExtension\Resource\Rendering;

use TYPO3\CMS\Core\Attribute\AsFileRenderer;
use TYPO3\CMS\Core\Resource\FileInterface;
use TYPO3\CMS\Core\Resource\Rendering\FileRendererInterface;
use TYPO3\CMS\Core\Utility\GeneralUtility;

#[AsFileRenderer(priority: 10)]
final readonly class PdfRenderer implements FileRendererInterface
{
  public function canRender(FileInterface $file): bool
  {
    return $file->getMimeType() === 'application/pdf';
  }

  public function render(
    FileInterface $file,
    int|string $width,
    int|string $height,
    array $options = [],
  ): string {
    // Width and height can carry a suffix like "m" or "c", the iframe
    // takes the number only. An empty value leaves out the attribute.
    $attributes = [
      'src' => $file->getPublicUrl(),
      'title' => $options['title'] ?? $file->getName(),
      'width' => (int)$width ?: null,
      'height' => (int)$height ?: null,
    ];
    return '<iframe ' . GeneralUtility::implodeAttributes($attributes, true)
      . '></iframe>';
  }
}

Method canRender()

Return true if the renderer can render the given file or file reference.

Method render()

Return the HTML output for the file. $width and $height are numbers or numbers with a suffix like 200m or 200c, as in the width property of imgResource. $options contains the arguments of the ViewHelper <f:media> and the values of its argument additionalConfig.

A file renderer is a service, so it can use dependency injection in its constructor.

Priority of file renderers 

TYPO3 asks the file renderers in the order of their priority, the highest first. The first renderer that can render the file renders it. The renderers of TYPO3 Core have the priority 0, so a renderer with a higher priority takes precedence, for example to replace the video renderer. Give a renderer a negative priority to ask it only after the renderers of TYPO3 Core. The order of renderers with the same priority is not defined. Give each renderer its own priority if the order matters.

Register a file renderer with the service tag fal.file_renderer 

Instead of the attribute, the service tag fal.file_renderer can be used:

services:
  # Place here the default dependency injection configuration

  MyVendor\MyExtension\Resource\Rendering\PdfRenderer:
    tags:
      - name: fal.file_renderer
        priority: 10

Render a file with the ViewHelper <f:media> 

The ViewHelper <f:media> renders each file with the file renderer that can render it. With the example renderer, PDF files are embedded in an <iframe> , and images are still rendered as images:

<f:for each="{files}" as="file">
    <f:media file="{file}" width="800" height="600" title="{file.title}" />
</f:for>

The argument title reaches the renderer in $options. If a file has no title, the example renderer uses the file name.