DOM和SimpleXMLDoesnt使用PHP在浏览器中以XML格式显示数据

这是我的PHP代码，用于使用SimpleXML和DOM从URL读取XML，以更改一些参数并将其显示在网页上

我正在阅读的提要位于http://tinyurl.com/boy7mr5

<?php
  $xml = simplexml_load_file('http://www.abc.com');

  $doc = new DOMDocument();
  $doc->formatOutput = true;
  $r = $doc->createElement( "All_Products" );
  $doc->appendChild( $r );
  foreach( $xml as $Product)
  {

 $b = $doc->createElement( "Product" );
   $doc->appendChild( $b );
  foreach($Product as $prname=>$value)
  {

  $prname1  = $doc->createElement( $prname );
  $prname1->appendChild(
  $doc->createTextNode( $value )
  );
  $b->appendChild($prname1);
  if($prname=='ProductName')
  {
  $ProductURL = $doc->createElement( "ProductURL" );
  $ProductURL->appendChild(
  $doc->createTextNode('http://www.abc.com/'.$Product->ProductName.'-p/'.$Product->ProductCode .'.htm' )
  );
  $b->appendChild( $ProductURL );
  }
  if($prname=='Categories'){
foreach($value as $catname=>$catvalue)
  {
   $c = $doc->createElement( "Category" );
   $doc->appendChild( $c );
  foreach($catvalue as $catname1=>$catvalue1)
  {
 // echo $catname1."==".$catvalue1;
    $catname12 = $doc->createElement( $catname1);
  $catname12 ->appendChild(
  $doc->createTextNode(htmlspecialchars_decode($catvalue1) )
  );
  $c->appendChild( $catname12);
  }
   $prname1->appendChild( $c );
  }
  }

  }
  $r->appendChild( $b );
  }
  echo $doc->saveXML();
  ?>

最后一行按原样打印所有XML，但它显示了垃圾数据，正如您在这个url中看到的那样http://tinyurl.com/bty8286.

我希望数据看起来像这样http://tinyurl.com/boy7mr5在浏览器中，我应该在代码