Add an option to force convert images to WebP

Author: dtdesign

com.woltlab.wcf/option.xml

@@ -531,6 +531,13 @@
 				<defaultvalue>gd</defaultvalue>
 				<selectoptions>gd:wcf.acp.option.image_adapter_type.gd
 imagick:wcf.acp.option.image_adapter_type.imagick</selectoptions>
+			</option>
+			<option name="image_convert_format">
+				<categoryname>general.system.image</categoryname>
+				<optiontype>radioButton</optiontype>
+				<defaultvalue>webp</defaultvalue>
+				<selectoptions>keep:wcf.acp.option.image_convert_format.keep
+webp:wcf.acp.option.image_convert_format.webp</selectoptions>
 			</option>
 			<!-- /general.system.image -->
 			<!-- general.system.search -->

constants.php

@@ -227,3 +227,4 @@
 \define('SERVICE_WORKER_PRIVATE_KEY', '');
 \define('SERVICE_WORKER_PUBLIC_KEY', '');
 \define('RECAPTCHA_PRIVATEKEY_V3', '');
+\define('IMAGE_CONVERT_FORMAT', 'webp');

wcfsetup/install/files/lib/system/endpoint/controller/core/files/GenerateThumbnails.class.php

@@ -29,6 +29,7 @@ public function __invoke(ServerRequestInterface $request, array $variables): Res
         $file = Helper::fetchObjectFromRequestParameter($variables['id'], File::class);
 
         FileProcessor::getInstance()->generateWebpVariant($file);
+        $file = FileProcessor::getInstance()->convertImageFormat($file);
         FileProcessor::getInstance()->generateThumbnails($file);
 
         $thumbnails = [];

wcfsetup/install/files/lib/system/file/command/ReplaceWithWebpVariant.class.php

@@ -0,0 +1,51 @@
+<?php
+
+namespace wcf\system\file\command;
+
+use wcf\data\file\File;
+
+/**
+ * Converts an image to its WebP variant by replacing it with it.
+ *
+ * @author      Alexander Ebert
+ * @copyright   2001-2025 WoltLab GmbH
+ * @license     GNU Lesser General Public License <http://opensource.org/licenses/lgpl-license.php>
+ * @since       6.2
+ */
+final class ReplaceWithWebpVariant
+{
+    public function __construct(
+        private readonly File $file,
+    ) {}
+
+    public function __invoke(): File
+    {
+        $pathnameWebp = $this->file->getPathnameWebp();
+        if ($pathnameWebp === null) {
+            return $this->file;
+        }
+
+        $command = new ReplaceFileSource(
+            $this->file,
+            $pathnameWebp,
+            $this->getNewFilename(),
+        );
+        $command();
+
+        return new File($this->file->fileID);
+    }
+
+    private function getNewFilename(): string
+    {
+        $filename = \preg_replace(
+            '~\.(?:jpe?g|png)$~i',
+            '',
+            $this->file->filename,
+        );
+
+        return \sprintf(
+            "%s.webp",
+            $filename,
+        );
+    }
+}

wcfsetup/install/files/lib/system/file/processor/FileProcessor.class.php

@@ -13,6 +13,7 @@
 use wcf\system\database\util\PreparedStatementConditionBuilder;
 use wcf\system\event\EventHandler;
 use wcf\system\exception\SystemException;
+use wcf\system\file\command\ReplaceWithWebpVariant;
 use wcf\system\file\processor\exception\DamagedImage;
 use wcf\system\image\adapter\exception\ImageNotProcessable;
 use wcf\system\image\adapter\exception\ImageNotReadable;
@@ -424,6 +425,21 @@ public function copy(File $oldFile, string $objectType): File
         return $newFile;
     }
 
+    public function convertImageFormat(File $file): File
+    {
+        switch (\IMAGE_CONVERT_FORMAT) {
+            case 'keep':
+                return $file;
+
+            case 'webp':
+                $command = new ReplaceWithWebpVariant($file);
+                return $command();
+
+            default:
+                throw new \LogicException("Unreachable");
+        }
+    }
+
     private function copyThumbnails(int $oldFileID, int $newFileID): void
     {
         $thumbnailList = new FileThumbnailList();

wcfsetup/install/files/lib/system/worker/FileRebuildDataWorker.class.php

@@ -5,6 +5,7 @@
 use wcf\data\file\File;
 use wcf\data\file\FileEditor;
 use wcf\data\file\FileList;
+use wcf\system\file\command\ReplaceWithWebpVariant;
 use wcf\system\file\processor\exception\DamagedImage;
 use wcf\system\file\processor\FileProcessor;
 use wcf\util\FileUtil;
@@ -49,9 +50,10 @@ public function execute()
         $this->fixMimeType();
 
         $damagedFileIDs = [];
-        foreach ($this->objectList as $file) {
+        foreach ($this->objectList->getObjects() as $file) {
             try {
                 FileProcessor::getInstance()->generateWebpVariant($file);
+                $file = FileProcessor::getInstance()->convertImageFormat($file);
                 FileProcessor::getInstance()->generateThumbnails($file);
             } catch (DamagedImage $e) {
                 logThrowable($e);