/* Write a sitmap.xml */
	public function writeSitemap() {
		// Your domain
		$domain = "https://mydomain.ch/";
		
		// Array für error reporting
		$errors = [];
	
		$code = "";
		// XML prolog
		$code .= "<?xml version=\"1.0\" encoding=\"UTF-8\"?>\r\n";
		// XML root element
		$code .= "<urlset xmlns=\"http://www.sitemaps.org/schemas/sitemap/0.9\">\r\n";
		
		// Add the URL of the homepage
		$code .= "\t<url>\r\n";
		$home = $domain."index.php";
		$code .= "\t\t<loc>".$home."</loc>\r\n";
		$fileTimeHome = filemtime("index.php");
		$lastModifiedHome = date("Y-m-d", $fileTimeHome);
		$code .= "\t\t<lastmod>".$lastModifiedHome."</lastmod>\r\n";
		$code .= "\t</url>\r\n";
		
		// All pages
		foreach ($this->structure as  $key => $out1) {
			$folder = $key."/";
			foreach ($out1 as $out2) {
  				$file = $folder.$out2['fileName'];
				if (file_exists($file)) {
					$code .= "\t<url>\n";
					$url = $domain.$file;
					$code .= "\t\t<loc>".$url."</loc>\r\n";
					$fileTime = filemtime($file);
    				$lastModified = date("Y-m-d", $fileTime);
    				$code .= "\t\t<lastmod>".$lastModified."</lastmod>\r\n";
    				$code .= "\t</url>\r\n";
				}
				else {
					$errors[] = "Nicht gefunden: ".$file;
				}
    		}
    	}
    	// End XML root element
		$code .= "</urlset>\r\n";
		
		// Write Sitemap-File 
		$handle = fopen("sitemap.xml","w");
		fwrite($handle,$code);
		fclose($handle);
		
		// Are there errors?
		$nrErrors = count($errors);
		
		if ($nrErrors > 0) {
			$str = "Ich habe die Sitemap geschrieben. Leider konnte ich nicht alle Files finden:<br>";
			foreach ($errors as $out3){
				$str .= $out3."<br>";
			}
			$str .= "<br><strong>Bitte checke das Array mit der Struktur nochmals!</strong>";
			return $str;
		}
		else {
			return "Es gab keine Fehler. Habe das Sitemap-File geschrieben.";
		}
	}