* * For the full copyright and license information, please view the LICENSE * file that was distributed with this source code. */ namespace Presta\SitemapBundle\Sitemap\Url; use Presta\SitemapBundle\Sitemap\Utils; /** * Url decorator to add alternatives to a sitemap Url. * * https://developers.google.com/search/docs/advanced/crawling/localized-versions */ class GoogleMultilangUrlDecorator extends UrlDecorator { public const REL_ALTERNATE = 'alternate'; /** * @var array */ protected $customNamespaces = ['xhtml' => 'http://www.w3.org/1999/xhtml']; /** * @var string */ protected $linkXml = ''; /** * add an alternative language to the url * * @param string $href Valid url of the translated page * @param string $hreflang Valid language code @see * http://www.w3.org/TR/xhtml-modularization/abstraction.html#dt_LanguageCode * @param string|null $rel (default is alternate) - valid link type @see * http://www.w3.org/TR/xhtml-modularization/abstraction.html#dt_LinkTypes * * @return GoogleMultilangUrlDecorator */ public function addLink(string $href, string $hreflang, ?string $rel = null): self { $this->linkXml .= $this->generateLinkXml($href, $hreflang, $rel); return $this; } /** * @param string $href * @param string $hreflang * @param string|null $rel * * @return string */ protected function generateLinkXml(string $href, string $hreflang, ?string $rel = null): string { if (null == $rel) { $rel = self::REL_ALTERNATE; } return ''; } /** * @inheritdoc */ public function toXml(): string { $baseXml = $this->urlDecorated->toXml(); return str_replace('', $this->linkXml . '', $baseXml); } }