WP_Sitemaps::render_sitemaps()

	public function render_sitemaps() {
		global $wp_query;

		$sitemap         = sanitize_text_field( get_query_var( 'sitemap' ) );
		$object_subtype  = sanitize_text_field( get_query_var( 'sitemap-subtype' ) );
		$stylesheet_type = sanitize_text_field( get_query_var( 'sitemap-stylesheet' ) );
		$paged           = absint( get_query_var( 'paged' ) );

		// Bail early if this isn't a sitemap or stylesheet route.
		if ( ! ( $sitemap || $stylesheet_type ) ) {
			return;
		}

		if ( ! $this->sitemaps_enabled() ) {
			$wp_query->set_404();
			status_header( 404 );
			return;
		}

		// Render stylesheet if this is stylesheet route.
		if ( $stylesheet_type ) {
			$stylesheet = new WP_Sitemaps_Stylesheet();

			$stylesheet->render_stylesheet( $stylesheet_type );
			exit;
		}

		// Render the index.
		if ( 'index' === $sitemap ) {
			$sitemap_list = $this->index->get_sitemap_list();

			$this->renderer->render_index( $sitemap_list );
			exit;
		}

		$provider = $this->registry->get_provider( $sitemap );

		if ( ! $provider ) {
			return;
		}

		if ( empty( $paged ) ) {
			$paged = 1;
		}

		$url_list = $provider->get_url_list( $paged, $object_subtype );

		// Force a 404 and bail early if no URLs are present.
		if ( empty( $url_list ) ) {
			$wp_query->set_404();
			status_header( 404 );
			return;
		}

		$this->renderer->render_sitemap( $url_list );
		exit;
	}