php中SimpleXML生成与解析xml文件

class SimpleXMLExtended extends SimpleXMLElement {
public function addCData($cdata_text) {
$node = dom_import_simplexml($this);
$no = $node->ownerDocument;
$node->appendChild($no->createCDATASection($cdata_text));
}
}
function array2xml($array, $xml = false){
if($xml === false){
$xml = new SimpleXMLExtended('');
}
foreach($array as $key => $value){
if(is_array($value)){
array2xml($value, $xml->addChild($key));
}else{
//如果包含汉字，转编码
if (preg_match("/([x81-xfe][x40-xfe])/", $value, $match)) {
$value = iconv('gbk', 'utf-8', $value);
}
$xml->$key = NULL; // VERY IMPORTANT! We need a node where to append
$xml->$key->addCData($value);
//$xml->$key->addAttribute('lang', 'en');
// $xml->addChild($key, $value);
}
}
return $xml->asXML();
}

$content =


HTTP
80
/index.html
5000
3000
2
3






XML;

$test = new SimpleXMLElement($content);

//获得ping_protocol的值
$ping_protocol = $test->global_setting->ping_protocol;
echo "ping_protocol : $ping_protocol n";

//打印出所有instance的IP
foreach ( $test->instances->instance as $instance) {
echo "IP: {$instance['ip']} n" ;
}