XPath对XML文件查找及修改

<?php
/*
<?xml version="1.0" encoding="utf-8"?>
<article>
    <item>
        <title name="t1">11</title>
        <content>content1</content>
        <pubdate>2009-10-11</pubdate>
    </item>
    <item>
        <title name="t2">title2</title>
        <content>content2</content>
        <pubdate>2009-11-11</pubdate>
    </item>
</article>
*/
if(!function_exists('l')) {
    function l() {
        echo '<br/>***********************************<br />';
    }
}
if(file_exists('test10_12.xml')) {
    $xml = simplexml_load_file('test10_12.xml');
     
    //利用xpath方法查找节点位置
    $query = $xml->xpath('//title[@name="t1"]/ancestor::item');
     
    var_dump($query);  //debug
    l();               
     
    //测试在title节点下新增子节点new
    $query[0]->title->addChild('new','new');
     
    //测试在title节点下新增属性fuck
    $query[0]->title->addAttribute('fuck','fuck you');
     
    //测试修改content节点值为hello,world
    $query[0]->content = 'hello,world';
     
    //不解释,你懂的
    $query[0]->asXML("10.xml");
}
/*End of PHP*/