setTagBuilder( new class () extends TagBuilder { public function addAttribute($attributeName, $attributeValue, $escapeSpecialCharacters = false): void { parent::addAttribute($attributeName, $attributeValue, false); } } ); parent::initialize(); } public function initializeArguments(): void { $this->registerTagAttribute('href', 'string', 'Define the URL of the resource (absolute or relative).', true); } public function render() { if ($href = $this->tag->getAttributes()['href']) { $absolutePath = GeneralUtility::getFileAbsFileName(str_replace('/_','_', $href)); $content = file_get_contents($absolutePath); if ($content) { /** @var PageRenderer $pageRenderer */ $pageRenderer = GeneralUtility::makeInstance(PageRenderer::class); $pageRenderer->addHeaderData(''); } } } }