Üstadlar bi bakabilir mi ? Rss Feed Hata Nerede ?

<?php
header('Content-type: text/xml'); ?>
<rss xmlns:content="http://purl.org/rss/1.0/modules/content/" xmlns:atom="http://www.w3.org/2005/Atom" version="2.0">
<?php

$servername = "localhost";
$username = "--";
$password = "--";
$dbname = "--";

$site = $_SERVER["HTTP_HOST"];
$tarih=date("Y-m-d");


function seo($url){
$url = trim($url);
$url = strtolower($url);
$find = array('<b>', '</b>');
$url = str_replace ($find, '', $url);
$url = preg_replace('/<(\/{0,1})img(.*?)(\/{0,1})\>/', 'image', $url);
$find = array(' ', '&quot;', '&amp;', '&', '\r\n', '\n', '/', '\\', '+', '<', '>');
$url = str_replace ($find, '-', $url);
$find = array('é', 'è', 'ë', 'ê', 'É', 'È', 'Ë', 'Ê');
$url = str_replace ($find, 'e', $url);
$find = array('í', 'ı', 'ì', 'î', 'ï', 'I', 'İ', 'Í', 'Ì', 'Î', 'Ï');
$url = str_replace ($find, 'i', $url);
$find = array('ó', 'ö', 'Ö', 'ò', 'ô', 'Ó', 'Ò', 'Ô');
$url = str_replace ($find, 'o', $url);
$find = array('á', 'ä', 'â', 'à', 'â', 'Ä', 'Â', 'Á', 'À', 'Â');
$url = str_replace ($find, 'a', $url);
$find = array('ú', 'ü', 'Ü', 'ù', 'û', 'Ú', 'Ù', 'Û');
$url = str_replace ($find, 'u', $url);
$find = array('ç', 'Ç');
$url = str_replace ($find, 'c', $url);
$find = array('ş', 'Ş');
$url = str_replace ($find, 's', $url);
$find = array('ğ', 'Ğ');
$url = str_replace ($find, 'g', $url);
$find = array('/[^a-z0-9\-<>]/', '/[\-]+/', '/<[^>]*>/');
$repl = array('', '-', '');
$url = preg_replace ($find, $repl, $url);
$url = str_replace ('--', '-', $url);
return $url;
}


// Create connection
$conn = new mysqli($servername, $username, $password, $dbname);
mysqli_set_charset($conn,'utf8');


?>
<channel>
<title>Site Başlığı</title>
<description>Site Açıklama</description>
<link><?php echo URL ?></link>
<language>tr</language>
<?php
$rssSql = query('SELECT * FROM news ORDER BY id DESC LIMIT 20');
while($icerik = row($rssSql)) { ?>
<item>
<title><?php echo $icerik['page_title'] ?></title>
<image>
<url><?php echo URL.'/img/'.$icerik['foto'] ?></url>
</image>
<link><?php echo URL,$icerik['news_name'] ?></link>
<pubDate><?php echo formatZaman($icerik['$tarih']) ?></pubDate>
<description><?php echo $icerik['page_description'] ?></description>
<language>tr</language>
<guid isPermaLink="true"><?php echo URL,$icerik['news_name'] ?></guid>
</item>
<?php
}
?>
<?php
$conn->close();
?>
</channel>
</rss>

 while ($icerik = mysql_fetch_array($rssSql)) { ... }

$rssSql = conn->query('SELECT * FROM news ORDER BY id DESC LIMIT 20');
while($icerik = $rssSql->fetch_assoc()) { ?>

public function clean($string) {
  $string = strtolower( preg_replace('@[\W_]+@', '-', $string) );
  $string = rtrim($string,'-');
  $string = strtolower($string);
  return $string;
  }

function replace_tr($text) {
  $text = trim($text);
  $search = array('Ç','ç','Ğ','ğ','ı','İ','Ö','ö','Ş','ş','Ü','ü',' ');
  $replace = array('c','c','g','g','i','i','o','o','s','s','u','u','-');
  $new_text = str_replace($search,$replace,$text);
  return $new_text;

<?php
require_once ('ayar.php'); //Veritabanı bağlantımızı yaptık.

$cek = $baglanti->get_row("SELECT * FROM ayarlar");
$url = _base;
header('Content-Type: text/xml; charset=utf-8', true); //set document header content type to be XML
$xml = new DOMDocument("1.0", "UTF-8"); // Create new DOM document.
 
//create "RSS" element
$rss = $xml->createElement("rss"); 
$rss_node = $xml->appendChild($rss); //add RSS element to XML node
$rss_node->setAttribute("version","2.0"); //set RSS version
 
//set attributes
$rss_node->setAttribute("xmlns:dc","http://purl.org/dc/elements/1.1/"); //xmlns:dc (info http://j.mp/1mHIl8e )
$rss_node->setAttribute("xmlns:content","http://purl.org/rss/1.0/modules/content/"); //xmlns:content (info http://j.mp/1og3n2W)
$rss_node->setAttribute("xmlns:atom","http://www.w3.org/2005/Atom");//xmlns:atom (http://j.mp/1tErCYX )
 
//Create RFC822 Date format to comply with RFC822
$date_f = date("D, d M Y H:i:s T", time());
$build_date = gmdate(DATE_RFC2822, strtotime($date_f));
 
//create "channel" element under "RSS" element
$channel = $xml->createElement("channel");  
$channel_node = $rss_node->appendChild($channel);
 
//a feed should contain an atom:link element (info http://j.mp/1nuzqeC)
$channel_atom_link = $xml->createElement("atom:link");  
$channel_atom_link->setAttribute("href","$url"); //url of the feed
$channel_atom_link->setAttribute("rel","self");
$channel_atom_link->setAttribute("type","application/rss+xml");
$channel_node->appendChild($channel_atom_link); 
 
//add general elements under "channel" node
$channel_node->appendChild($xml->createElement("title", "$cek->title | $cek->telefon")); //title
$channel_node->appendChild($xml->createElement("description", "$cek->keyw"));  //description
$channel_node->appendChild($xml->createElement("link", "$url")); //website link 
$channel_node->appendChild($xml->createElement("language", "tr-TR"));  //language
$channel_node->appendChild($xml->createElement("lastBuildDate", $build_date));  //last build date
$channel_node->appendChild($xml->createElement("generator", "$cek->title | $cek->telefon")); //generator
 
 
$cek = $baglanti->get_results(" SELECT * FROM urunler ORDER BY id DESC ");
 
if($cek){ //we have records 
    foreach($cek as $row) //loop through each row
    {
      $item_node = $channel_node->appendChild($xml->createElement("item")); //create a new node called "item"
      $title_node = $item_node->appendChild($xml->createElement("title", $row->urunadi)); //Add Title under "item"
      $link_node = $item_node->appendChild($xml->createElement("link", $url.strtolower($row->urunseo)."/")); //add link node under "item"
      
      //Unique identifier for the item (GUID)
      $guid_link = $xml->createElement("guid", $url.strtolower($row->urunseo)."/".md5($row->id));  
      $guid_link->setAttribute("isPermaLink","false");
      $guid_node = $item_node->appendChild($guid_link); 
     
      //create "description" node under "item"
      $description_node = $item_node->appendChild($xml->createElement("description"));  
      
      //fill description node with CDATA content
      $description_contents = $xml->createCDATASection(htmlentities($row->urunozellik));  
      $description_node->appendChild($description_contents); 
    
      //Published date
      $date_rfc = gmdate(DATE_RFC2822, strtotime($row->published));
      $pub_date = $xml->createElement("pubDate", turkce_tarih($row->tarih));  
      $pub_date_node = $item_node->appendChild($pub_date); 
 
    }
}
echo $xml->saveXML();
?>