Sitemap\Model\Sitemap::generateXml PHP Method

    protected function generateXml($documents, Request $request)
    {
        $xml = '<?xml version="1.0" encoding="UTF-8"?>';
        $xml .= '<urlset
            xmlns="http://www.sitemaps.org/schemas/sitemap/0.9"
            xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
            xsi:schemaLocation="http://www.sitemaps.org/schemas/sitemap/0.9
            http://www.sitemaps.org/schemas/sitemap/0.9/sitemap.xsd">';
        $url = $request->getBasePath();
        foreach ($documents as $document) {
            $xml .= '<url>';
            $xml .= '<loc><![CDATA[' . $url . $document->getUrl() . ']]></loc>';
            $xml .= '<lastmod>' . date('Y-m-d\\TH:i:s\\Z', strtotime($document->getUpdatedAt())) . '</lastmod>';
            $xml .= '<changefreq>weekly</changefreq>';
            $xml .= '<priority>0.5</priority>';
            $xml .= '</url>';
        }
        $xml .= '</urlset>';
        return $xml;
    }