FluidTYPO3\Vhs\ViewHelpers\Media\ExtensionViewHelper::render PHP Method

    public function render()
    {
        $filePath = $this->arguments['file'];
        if (true === empty($filePath)) {
            $filePath = $this->renderChildren();
            if (null === $filePath) {
                return '';
            }
        }
        $file = GeneralUtility::getFileAbsFileName($filePath);
        $parts = explode('.', basename($file));
        // file has no extension
        if (1 === count($parts)) {
            return '';
        }
        $extension = strtolower(array_pop($parts));
        return $extension;
    }