Una sitemap "al volo" per WordPress

<?php echo "<?xml version=\"1.0\" encoding=\"UTF-8\"?>\n"; ?>
<?php
// loading WP vars, functions and dB link
require( './wp-load.php' );
wp();
global $wpdb;
// DEFAULT CASE: no parameters (/wp-sitemap.php) -> posts and pages (sorted)
if (empty($_GET["type"])): ?>
<urlset xmlns="http://www.sitemaps.org/schemas/sitemap/0.9">
	<?php
	$locations = $wpdb->get_results("SELECT guid as loc, substr(post_date_gmt,1,10) as lastmod
		FROM $wpdb->posts WHERE post_status='publish' ORDER BY post_type DESC, post_date_gmt DESC");
	foreach ($locations as $location): ?>
<url>
		<loc><?php echo $location->loc; ?></loc>
		<lastmod><?php echo $location->lastmod; ?></lastmod>
	</url>
	<?php endforeach; ?>
<?php else :
	// POSTS SITEMAP CASE: post type parameter sent to script (/wp-sitemap?type=post) -> posts only
	if($_GET["type"]=="post"): ?>
<urlset xmlns="http://www.sitemaps.org/schemas/sitemap/0.9">
		<?php
		$locations = $wpdb->get_results("SELECT guid as loc, substr(post_date_gmt,1,10) as lastmod
			FROM $wpdb->posts WHERE post_status='publish' AND post_type='post' ORDER BY post_date_gmt DESC");
		foreach ($locations as $location): ?>
<url>
		<loc><?php echo $location->loc; ?></loc>
		<lastmod><?php echo $location->lastmod; ?></lastmod>
	</url>
		<?php endforeach; ?>
	<?php
	// PAGES SITEMAP CASE: post type parameter sent to script (/wp-sitemap?type=page) -> pages only
	elseif($_GET["type"]=="page"): ?>
<urlset xmlns="http://www.sitemaps.org/schemas/sitemap/0.9">
		<?php
		$locations = $wpdb->get_results("SELECT guid as loc, substr(post_date_gmt,1,10) as lastmod
			FROM $wpdb->posts WHERE post_status='publish' AND post_type='page' ORDER BY post_date_gmt DESC");
		foreach ($locations as $location): ?>
<url>
		<loc><?php echo $location->loc; ?></loc>
		<lastmod><?php echo $location->lastmod; ?></lastmod>
	</url>
		<?php endforeach; ?>
	<?php
	// SITEMAP-NEWS (Google) CASE: post type parameter sent to script (/wp-sitemap?type=posttogoogle) -> posts only
	// Note: You should be __already__ indexed by Google News to successfully use this case
	elseif($_GET["type"]=="posttogoogle"): ?>
<urlset xmlns="http://www.sitemaps.org/schemas/sitemap/0.9"
	xmlns:news="http://www.google.com/schemas/sitemap-news/0.9">
	<?php
		$locations = $wpdb->get_results("SELECT guid as loc, post_title as news_title, substr(post_date_gmt,1,10) AS news_date,
			group_concat(name SEPARATOR ', ') AS news_keywords FROM $wpdb->posts INNER JOIN $wpdb->term_relationships ON
			$wpdb->posts.ID=$wpdb->term_relationships.object_id INNER JOIN $wpdb->term_taxonomy ON
			$wpdb->term_relationships.term_taxonomy_id=$wpdb->term_taxonomy.term_taxonomy_id INNER JOIN $wpdb->terms ON
			$wpdb->term_relationships.term_taxonomy_id=$wpdb->terms.term_id WHERE post_status='publish' AND post_type='post'
			AND taxonomy='post_tag' GROUP BY ID ORDER BY post_date_gmt DESC");
		$blogname=get_bloginfo('name');
		$bloglang=get_bloginfo('language');
		foreach ($locations as $location): ?>
<url>
		<loc><?php echo $location->loc; ?></loc>
		<news:news>
			<news:publication>
				<news:name><?php echo $blogname; ?></news:name>
				<news:language><?php echo $bloglang; ?></news:language>
			</news:publication>
			<news:genres>Blog</news:genres>
			<news:publication_date><?php echo $location->news_date; ?></news:publication_date>
			<news:title><?php echo apply_filters('the_title_rss', $location->news_title); ?></news:title>
			<news:keywords><?php echo wp_specialchars(strtolower($location->news_keywords)); ?></news:keywords>
		</news:news>
	</url>
		<?php endforeach; ?>		

	<?php
	// TAGS SITEMAP CASE: (/wp-sitemap?type=tag) -> tags only
	elseif($_GET["type"]=="tag"): ?>
<urlset xmlns="http://www.sitemaps.org/schemas/sitemap/0.9">
		<?php
		$locations = $wpdb->get_results("SELECT slug, tag_history.tagdate AS lastmod FROM (SELECT $wpdb->term_relationships.term_taxonomy_id AS tagid, substr($wpdb->posts.post_date_gmt,1,10) AS tagdate FROM $wpdb->term_relationships INNER JOIN $wpdb->term_taxonomy ON $wpdb->term_taxonomy.term_taxonomy_id=$wpdb->term_relationships.term_taxonomy_id INNER JOIN $wpdb->posts ON $wpdb->posts.ID=$wpdb->term_relationships.object_id WHERE taxonomy='post_tag' AND description!='' ORDER BY post_date_gmt DESC, $wpdb->posts.post_title) AS tag_history INNER JOIN $wpdb->terms ON $wpdb->terms.term_id=tag_history.tagid GROUP BY tag_history.tagid ORDER BY tag_history.tagdate DESC");
		foreach ($locations as $location): ?>
<url>
		<loc><?php echo site_url(); ?>/tag/<?php echo $location->slug; ?>/</loc>
		<lastmod><?php echo $location->lastmod; ?></lastmod>
	</url>
		<?php endforeach; ?>		

	<?php else:

	endif; ?>
<?php endif; ?>
</urlset>