messages.xml
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System Down for Maintenance
Going down for maintenance soon!
Joe SystemGod
systemgod@someserver.com
March 4, 2004
10
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xml 是一种创建元数据的语言,元数据是描述其它数据的数据,PHP中的XML处理是基于LIBXML2的，安装时默认开启。
可以通过phpinfo()函数查看是否开启了XML处理模块,DOM,LIBXML,SAMPLEXML。
首先,通过samplexml_load_file函数把xml文件加载到一个对象中,samplexml_load_file可以用户远程文件.
例如:
$xml = samplexml_load_file("messages.xml"); // 本地文件系统,当前目录
$xml = samplexml_load_file("http://www.xml.org.cn/messages.xml"); // 远程web服务器
用 var_dump($xml) 和 print_r($xml) 分别输出其结构.var_dump给出了变量的类型和长度,而print_r可读性更强
输出对象中的所有元素名称和它的值.
echo $xml->MessageTitle; //输出消息的标题
echo $xml->MessageBody; // 输出消息体
echo $xml->MessageAuthor; //消息的作者
echo $xml->MessageDate; // 消息产生的日期
echo $xml->MessageNumber; // 消息代码
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另外,还有一个函数,可以把XML字符串加载到一个simplexml对象中取
$channel =<<<_XML_
What's For Dinner
http://menu.example.com/
These are your choices of what to eat tonight.
_XML_;
$xml = simplexml_load_string($channel);
===================================================
rss.xml
=============================================
What's For Dinner
http://menu.example.com/
These are your choices of what to eat tonight.
Braised Sea Cucumber
http://menu.example.com/dishes.php?dish=cuke
Gentle flavors of the sea that nourish and refresh you.
Baked Giblets with Salt
http://menu.example.com/dishes.php?dish=giblets
Rich giblet flavor infused with salt and spice.
Abalone with Marrow and Duck Feet
http://menu.example.com/dishes.php?dish=abalone
There's no mistaking the special pleasure of abalone.
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1.访问具有相同元素名称的节点
2.通过foreach循环所有相同元素名称的子节点
foreach($xml->channel->item as $key=>$value)
{
print "Title: " . $item->title . "\n";
}
3.输出整个文档
echo $xml->asXML();
4.把节点作为字符串输出
echo $xml->channel->item[0]->asXML();
这将输出文本
Braised Sea Cucumber
http://menu.example.com/dishes.php?dish=cuke
Gentle flavors of the sea that nourish and refresh you.
带文件名参数的asXML将会把原本输出的内容保存为一个文件
$xml->channel->item[0]->asXML("item[0].xml");
完整的代码:
rss.xml
=====
What's For Dinner
http://menu.example.com/
These are your choices of what to eat tonight.
Braised Sea Cucumber
http://menu.example.com/dishes.php?dish=cuke
Gentle flavors of the sea that nourish and refresh you.
Baked Giblets with Salt
http://menu.example.com/dishes.php?dish=giblets
Rich giblet flavor infused with salt and spice.
Abalone with Marrow and Duck Feet
http://menu.example.com/dishes.php?dish=abalone
There's no mistaking the special pleasure of abalone.
rss.php
======
$xml = simplexml_load_file("rss.xml");
echo "".$xml->channel->title."
";
echo "";
echo "Title:".$xml->channel->item[0]->title."";
echo "Title:".$xml->channel->item[1]->title."";
echo "Title:".$xml->channel->item[2]->title."";
echo "";
print "Title: " . $xml->channel->item[0]->title . "\n
";
print "Title: " . $xml->channel->item[1]->title . "\n
";
print "Title: " . $xml->channel->item[2]->title . "\n
";
echo "";
foreach ($xml->channel->item[0] as $element_name => $content) {
print "The $element_name is $content\n
";
}
echo "";
print_r($xml);
echo $xml->channel->item[0]->asXML();
?>
任何XML文本在输出前最好用 htmlentiteis() 函数编码后再输出,否这可能出现问题