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XML 是一種創建元數據的語言,元數據是描述其它數據的數據,PHP中的XML處理是基於LIBXML2的，安裝時默認開啟。
可以通過PHPinfo()函數查看是否開啟了XML處理模塊,DOM,LIBXML,SAMPLEXML。
首先,通過samplexml_load_file函數把xml文件加載到一個對象中,sampleXML_load_file可以用戶遠程文件.
例如:
$xml = samplexml_load_file("messages.XML"); // 本地文件系統,當前目錄
$xml = sampleXML_load_file("http://www.xml.org.cn/messages.XML"); // 遠程web服務器
用 var_dump($xml) 和 print_r($XML) 分別輸出其結構.var_dump給出了變量的類型和長度,而print_r可讀性更強
輸出對象中的所有元素名稱和它的值.
echo $XML->MessageTitle; //輸出消息的標題
echo $XML->MessageBody; // 輸出消息體
echo $XML->MessageAuthor; //消息的作者
echo $XML->MessageDate; // 消息產生的日期
echo $XML->MessageNumber; // 消息代碼
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另外,還有一個函數,可以把XML字符串加載到一個simpleXML對象中取
$channel =<<<_XML_
<channel>
<title>What's For Dinner</title>
<link>http://menu.example.com/</link>
<description>These are your choices of what to eat tonight. </description>
</channel>
_XML_;
$xml = simpleXML_load_string($channel);
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rss.XML
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<?XML version="1.0" encoding="utf-8"?>
<rss version="0.91">
<channel>
<title>What's For Dinner</title>
<link>http://menu.example.com/</link>
<description>These are your choices of what to eat tonight.</description>
<item>
<title>Braised Sea Cucumber</title>
<link>http://menu.example.com/dishes.PHP?dish=cuke</link>
<description>Gentle flavors of the sea that nourish and refresh you. </description>
</item>
<item>
<title>Baked Giblets with Salt</title>
<link>http://menu.example.com/dishes.PHP?dish=giblets</link>
<description>Rich giblet flavor infused with salt and spice. </description>
</item>
<item>
<title>Abalone with Marrow and Duck Feet</title>
<link>http://menu.example.com/dishes.PHP?dish=abalone</link>
<description>There's no mistaking the special pleasure of abalone. </description>
</item>
</channel>
</rss>
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1.訪問具有相同元素名稱的節點
2.通過foreach循環所有相同元素名稱的子節點
foreach($XML->channel->item as $key=>$value)
{
print "Title: " . $item->title . "\n";
}
3.輸出整個文檔
echo $xml->asXML();
4.把節點作為字符串輸出
echo $xml->channel->item[0]->asXML();
這將輸出文本
<item>
<title>Braised Sea Cucumber</title>
<link>http://menu.example.com/dishes.PHP?dish=cuke</link>
<description>Gentle flavors of the sea that nourish and refresh you. </description>
</item>
帶文件名參數的asXML將會把原本輸出的內容保存為一個文件
$xml->channel->item[0]->asXML("item[0].XML");
完整的代碼:
rss.XML
=====
<?XML version="1.0" encoding="utf-8"?>
<rss version="0.91">
<channel>
<title>What's For Dinner</title>
<link>http://menu.example.com/</link>
<description>These are your choices of what to eat tonight.</description>
<item>
<title>Braised Sea Cucumber</title>
<link>http://menu.example.com/dishes.PHP?dish=cuke</link>
<description>Gentle flavors of the sea that nourish and refresh you. </description>
</item>
<item>
<title>Baked Giblets with Salt</title>
<link>http://menu.example.com/dishes.PHP?dish=giblets</link>
<description>Rich giblet flavor infused with salt and spice. </description>
</item>
<item>
<title>Abalone with Marrow and Duck Feet</title>
<link>http://menu.example.com/dishes.PHP?dish=abalone</link>
<description>There's no mistaking the special pleasure of abalone. </description>
</item>
</channel>
</rss>
rss.PHP
======
<?PHP
$xml = simplexml_load_file("rss.XML");
echo "<h3>".$XML->channel->title."</h3><br>";
echo "<ul>";
echo "<li>Title:".$XML->channel->item[0]->title."</li>";
echo "<li>Title:".$XML->channel->item[1]->title."</li>";
echo "<li>Title:".$XML->channel->item[2]->title."</li>";
echo "</ul>";
print "Title: " . $XML->channel->item[0]->title . "\n<br>";
print "Title: " . $XML->channel->item[1]->title . "\n<br>";
print "Title: " . $XML->channel->item[2]->title . "\n<br>";
echo "<hr>";
foreach ($XML->channel->item[0] as $element_name => $content) {
print "The $element_name is $content\n<br>";
}
echo "<hr>";
print_r($XML);
echo $xml->channel->item[0]->asXML();
?>
任何XML文本在輸出前最好用 Htmlentiteis() 函數編碼後再輸出,否這可能出現問題