SimpleXML和XMLReader 解析RSSFeed

<?php
function load_file($url) { 
 $ch = curl_init($url); 
 #Return http response in string 
 curl_setopt($ch, CURLOPT_RETURNTRANSFER, true); 
 $xml = simplexml_load_string(curl_exec($ch)); 
 return $xml; 
}
 $feedurl = 'http://site.com/feed/'; 
 $rss = load_file($feedurl); 
 foreach ($rss->channel->item as $item) { 
 echo"<h2>". $item->title ."</h2>"; 
 echo"<p>". $item->description ."</p>"; 
}
?>

<?php
$xml= new XMLReader();
$xml->open('example.xml');
while($xml->read()){
switch($xml->nodeType){
 case 1:
 echo $xml->name."<br>";
break;
 case 15 :
 echo"/".$xml->name."<br>";
break;
 case 3:
 echo"[".trim($xml->value)."]<br>";
break;
 case 14:
break;
}
}
?>