PHP5中使用DOM控制XML实现代码_php技巧

下面的例子简单的演示了DOM对XML的操作，详细解释请看代码中的注释
代码如下:

<br><!--? <BR-->/************************************************ <br>** use XML in PHP5 <br>** reference site: <br>** http://cn.php.com/manual/zh/ref.dom.php <br>** the follow codes need PHP5 support <br>*************************************************/ <br><br>//首先要创建一个DOMDocument对象 <br>$dom = new DomDocument(); <br>//然后载入XML文件 <br>$dom -> load("test.xml"); <br><br>//

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 "

---

取得所有的title元素:

---

";
$titles = $dom -> getElementsByTagName("title");
foreach ($titles as $node){
echo $node -> textContent . "
";
//这样也可以
//echo $node->firstChild->data . "
";
}

/*
echo "

---

从根结点遍历所有结点：
";
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 "

---

使用XPath查询的title节点结果:

---

";
$xpath = new domxpath($dom);
$titles = $xpath->query("/rss/channel/item/title");
foreach ($titles as $node){
echo $node->textContent."
";
}
/*
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 "

---

查看newfile.xml";

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

下面是test.xml文件代码：
代码如下:

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