PHP5中使用DOM控制XML实现代码

<?
/************************************************
** use xml in php5
** reference site:
** http://cn.php.net/manual/zh/ref.dom.php
** the follow codes need php5 support
*************************************************/

//首先要创建一个domdocument对象
$dom = new domdocument();
//然后载入xml文件
$dom -> load("test.xml");

//输出xml文件
//header("content-type: text/xml;charset=gb2312");
//echo $dom -> savexml();

//保存xml文件，返回值为int（文件大小，以字节为单位）
//$dom -> save("newfile.xml");

echo "<hr/>取得所有的title元素:<hr/>";
$titles = $dom -> getelementsbytagname("title");
foreach ($titles as $node){
echo $node -> textcontent . "<br/>";
//这样也可以
//echo $node->firstchild->data . "<br/>";
}

/*
echo "<hr/>从根结点遍历所有结点：<br/>";
foreach ($dom->documentelement->childnodes as $items) {
//如果节点是一个元素(nodetype == 1)并且名字是item就继续循环
if ($items->nodetype == 1 && $items->nodename == "item") {
foreach ($items->childnodes as $titles) {
//如果节点是一个元素，并且名字是title就打印它.
if ($titles->nodetype == 1 && $titles->nodename == "title") {
print $titles->textcontent . "\n";
}
}
}
}
*/

//使用xpath查询数据
echo "<hr/>使用xpath查询的title节点结果:<hr/>";
$xpath = new domxpath($dom);
$titles = $xpath->query("/rss/channel/item/title");
foreach ($titles as $node){
echo $node->textcontent."<br/>";
}
/*
这样和使用getelementsbytagname()方法差不多，但是xpath要强大的多
深入一点可能是这样：
/rss/channel/item[position() = 1]/title 返回第一个item元素的所有
/rss/channel/item/title[@id = '23'] 返回所有含有id属性并且值为23的title
/rss/channel/&folder&/title 返回所有articles元素下面的title(译者注：&folder&代表目录深度)
*/


//向dom中写入新数据
$item = $dom->createelement("item");
$title = $dom->createelement("title");
$titletext = $dom->createtextnode("title text");
$title->appendchild($titletext);
$item->appendchild($title);
$dom->documentelement->getelementsbytagname('channel')->item(0)->appendchild($item);

//从dom中删除节点
//$dom->documentelement->removechild($dom->documentelement->getelementsbytagname("channel")->item(0));
//或者使用xpath查询出节点再删除
//$dom->documentelement->removechild($xpath->query("/rss/channel")->item(0));
//$dom->save("newfile.xml");

//从dom中修改节点数据
//修改第一个title的文件
//这个地方比较笨，新创建一个节点，然后替换旧的节点。如果哪位朋友有其他好的方法请一定要告诉我
$firsttitle = $xpath->query("/rss/channel/item/title")->item(0);
$newtitle = $dom->createelement("title");
$newtitle->appendchild(new domtext("this's the new title text!!!"));
$firsttitle->parentnode->replacechild($newtitle, $firsttitle);
//修改属性
//$firsttitle = $xpath->query("/rss/channel/item/title")->item(0);
//$firsttitle->setattribute("orderby", "4");
$dom->save("newfile.xml");

echo "<hr/><a href=\"newfile.xml\">查看newfile.xml</a>";

//下面的代码获得并解析php.net的首页，将返第一个title元素的内容。
/*
$dom->loadhtmlfile("http://www.php.net/");
$title = $dom->getelementsbytagname("title");
print $title->item(0)->textcontent;
*/
?>

<?xml version="1.0" encoding="gb2312"?>
<rss version="2.0">
<channel>
<title>javascript</title>
<link>http://blog.csdn.net/zhongmao/category/29515.aspx</link>
<description>javascript</description>
<language>zh-chs</language>
<generator>.text version 0.958.2004.2001</generator>
<item>
<creator>zhongmao</creator>
<title orderby="1">out put excel used javascript</title>
<link>http://blog.csdn.net/zhongmao/archive/2004/09/15/105385.aspx</link>
<pubdate>wed, 15 sep 2004 13:32:00 gmt</pubdate>
<guid>http://blog.csdn.net/zhongmao/archive/2004/09/15/105385.aspx</guid>
<comment>http://blog.csdn.net/zhongmao/comments/105385.aspx</comment>
<comments>http://blog.csdn.net/zhongmao/archive/2004/09/15/105385.aspx#feedback</comments>
<comments>2</comments>
<commentrss>http://blog.csdn.net/zhongmao/comments/commentrss/105385.aspx</commentrss>
<ping>http://blog.csdn.net/zhongmao/services/trackbacks/105385.aspx</ping>
<description>test description</description>
</item>
<item>
<creator>zhongmao</creator>
<title orderby="2">out put word used javascript</title>
<link>http://blog.csdn.net/zhongmao/archive/2004/08/06/67161.aspx</link>
<pubdate>fri, 06 aug 2004 16:33:00 gmt</pubdate>
<guid>http://blog.csdn.net/zhongmao/archive/2004/08/06/67161.aspx</guid>
<comment>http://blog.csdn.net/zhongmao/comments/67161.aspx</comment>
<comments>http://blog.csdn.net/zhongmao/archive/2004/08/06/67161.aspx#feedback</comments>
<comments>0</comments>
<commentrss>http://blog.csdn.net/zhongmao/comments/commentrss/67161.aspx</commentrss>
<ping>http://blog.csdn.net/zhongmao/services/trackbacks/67161.aspx</ping>
<description>test word description</description>
</item>
<item>
<creator>zhongmao</creator>
<title orderby="3">xmlhttp</title>
<link>http://blog.csdn.net/zhongmao/archive/2004/08/02/58417.aspx</link>
<pubdate>mon, 02 aug 2004 10:11:00 gmt</pubdate>
<guid>http://blog.csdn.net/zhongmao/archive/2004/08/02/58417.aspx</guid>
<comment>http://blog.csdn.net/zhongmao/comments/58417.aspx</comment>
<comments>http://blog.csdn.net/zhongmao/archive/2004/08/02/58417.aspx#feedback</comments>
<comments>0</comments>
<commentrss>http://blog.csdn.net/zhongmao/comments/commentrss/58417.aspx</commentrss>
<ping>http://blog.csdn.net/zhongmao/services/trackbacks/58417.aspx</ping>
<description>xmlhttpaaa asd bb cc dd</description>
</item>
</channel>
</rss>