public function process(AssetInterface $asset, AssetFactory $factory) { $path = $asset->getTargetPath(); $ext = pathinfo($path, PATHINFO_EXTENSION); $lastModified = $factory->getLastModified($asset); if (null !== $lastModified) { $path = substr_replace($path, "{$lastModified}.{$ext}", -1 * strlen($ext)); $asset->setTargetPath($path); } }