vichan/templates/themes/sitemap/theme.php

<?php
	require 'info.php';
	
	function sitemap_build($action, $settings, $board) {
		global $config;
		
		// Possible values for $action:
		//	- all (rebuild everything, initialization)
		//	- news (news has been updated)
		//	- boards (board list changed)
		//	- post (a post has been made)
		//	- thread (a thread has been made)

		if ($action != 'all') { 	
			if ($action != 'post-thread' && $action != 'post-delete')
				return;
		
			if (isset($settings['regen_time']) && $settings['regen_time'] > 0) {
				if ($last_gen = @filemtime($settings['path'])) {
					if (time() - $last_gen < (int)$settings['regen_time'])
						return; // Too soon
				}
			}
		}

		$action = generation_strategy('sb_sitemap', array());

		if ($action == 'delete') {
			file_unlink($settings['path']);
		}
		elseif ($action == 'rebuild') {
			$boards = explode(' ', $settings['boards']);
		
			$threads = array();
		
			foreach ($boards as $board) {
				$query = query(sprintf("SELECT `id`, `id` AS `thread_id`, `slug`, (SELECT `time` FROM ``posts_%s`` WHERE `thread` = `thread_id` OR `id` = `thread_id` ORDER BY `time` DESC LIMIT 1) AS `lastmod` FROM ``posts_%s`` WHERE `thread` IS NULL", $board, $board)) or error(db_error());
				$threads[$board] = $query->fetchAll(PDO::FETCH_ASSOC);
			}
				
			file_write($settings['path'], Element('themes/sitemap/sitemap.xml', Array(
				'settings' => $settings,
				'config' => $config,
				'threads' => $threads,
				'boards' => $boards,
			)));
		}
	}