用PHP的DOM控件来创建XML输出

/*
用PHP的DOM控件来创建XML输出
设置输出内容的类型为xml
*/
header('Content-Type: text/xml;');
//创建新的xml文件
$dom = new DOMDocument('1.0', 'utf-8');
//建立<response>元素
$response = $dom->createElement('response');
$dom->appendChild($response);
//建立<books>元素并将其作为<response>的子元素
$books = $dom->createElement('books');
$response->appendChild($books);
//为book创建标题
$title = $dom->createElement('title');
$titleText = $dom->createTextNode('PHP与AJAX');
$title->appendChild($titleText);
//为book创建isbn元素
$isbn = $dom->createElement('isbn');
$isbnText = $dom->createTextNode('1-21258986');
$isbn->appendChild($isbnText);
//创建book元素
$book = $dom->createElement('book');
$book->appendChild($title);
$book->appendChild($isbn);
//创建book元素属性节点
$bookid = $dom->createAttribute("bookid");
$book->appendChild($bookid);
//创建属性值节点
$bookidValue = $dom->createTextNode("4");
$bookid->appendChild($bookidValue);
//将<book>作为<books>子元素
$books->appendChild($book);
//在一字符串变量中建立XML结构
$xmlString = $dom->saveXML();
//输出XML字符串
echo $xmlString;

输出：
<?xml version="1.0" encoding="utf-8"?>
<response>
<books>
<book bookid="4">
<title>PHP与AJAX</title>
<isbn>1-21258986</isbn>
</book>
</books>
</response>