FluidTYPO3\Vhs\ViewHelpers\Page\Header\CanonicalViewHelper::render PHP Метод

    public function render()
    {
        if ('BE' === TYPO3_MODE) {
            return '';
        }
        $pageUid = (int) $this->arguments['pageUid'];
        if (0 === $pageUid) {
            $pageUid = $GLOBALS['TSFE']->id;
        }
        $queryStringMethod = $this->arguments['queryStringMethod'];
        if (!in_array($queryStringMethod, ['GET', 'POST', 'GET,POST'], true)) {
            throw new \InvalidArgumentException('The parameter "queryStringMethods" must be one of "GET", "POST" or "GET,POST".', 1475337546);
        }
        $uriBuilder = $this->controllerContext->getUriBuilder();
        $uri = $uriBuilder->reset()->setTargetPageUid($pageUid)->setUseCacheHash(true)->setCreateAbsoluteUri(true)->setAddQueryString(true)->setAddQueryStringMethod($queryStringMethod)->setArgumentsToBeExcludedFromQueryString(['id'])->build();
        if (true === empty($uri)) {
            return null;
        }
        $uri = $GLOBALS['TSFE']->baseUrlWrap($uri);
        $this->tag->addAttribute('rel', 'canonical');
        $this->tag->addAttribute('href', $uri, false);
        $renderedTag = $this->tag->render();
        if (1 === (int) $GLOBALS['TSFE']->config['config']['disableAllHeaderCode']) {
            return $renderedTag;
        }
        static::getPageRenderer()->addMetaTag($renderedTag);
    }