wp-includes/sitemaps/class-wp-sitemaps-renderer.php:146Gets XML for a sitemap index.
$sitemapsarraystring|false public function get_sitemap_index_xml( $sitemaps ) { $sitemap_index = new SimpleXMLElement( sprintf( '%1$s%2$s%3$s', '<?xml version="1.0" encoding="UTF-8" ?>', $this->stylesheet_index, '<sitemapindex xmlns="http://www.sitemaps.org/schemas/sitemap/0.9" />' ) ); foreach ( $sitemaps as $entry ) { $sitemap = $sitemap_index->addChild( 'sitemap' ); // Add each element as a child node to the <sitemap> entry. foreach ( $entry as $name => $value ) { if ( 'loc' === $name ) { $sitemap->addChild( $name, esc_url( $value ) ); } elseif ( 'lastmod' === $name ) { $sitemap->addChild( $name, esc_xml( $value ) ); } else { _doing_it_wrong( __METHOD__, sprintf( /* translators: %s: List of element names. */ __( 'Fields other than %s are not currently supported for the sitemap index.' ), implode( ',', array( 'loc', 'lastmod' ) ) ), '5.5.0' ); } } } return $sitemap_index->asXML(); }Introduced in 5.5.0. Unchanged from 6.7.7 through 7.1.0.
Signature, return type and hooks compared across 5 parsed releases.
src/wp-includes/sitemaps/class-wp-sitemaps-renderer.php, and regenerated for each WordPress release so it tracks the code rather than a snapshot of it.