youtube.xml
<Feed xmlns="http://www.w3.org/2005/Atom" xmlns:media="http://search.yahoo.com/mRSS/" xmlns:openSearch="http://a9.com/-/spec/opensearchRSS/1.0/" xmlns:gd="http://schemas.google.com/g/2005" xmlns:yt="http://gdata.youtube.com/schemas/2007">
<entry>
...
<yt:duration seconds="1870"/>
...
</entry>
</Feed>
update_videos.PHP
$source = 'youtube.xml';
// load as file
$youtube = new SimpleXMLElement($source, null, true);
foreach($youtube->entry as $item){
//title works
echo $item->title;
//Now how to get seconds? My attempt...
$namespaces = $item->getNameSpaces(true);
$yt = $item->children($namespaces['yt']);
$seconds = $yt->duration->attributes();
echo $seconds['seconds'];
//but doesn't work :(
}
解决方法:
你在问题中得到的代码确实有效.您已经正确地编写了可以通过使用带有XML命名空间相关参数$ns和$is_prefix的SimpleXMLElement::children()
method来从不在默认命名空间中的namespaced-element访问属性作为根元素:
$youtube->entry->children('yt', TRUE)->duration->attributes()->seconds; // is "1870"
由于这与您在问题中的基本相同,可以说您已经回答了自己的问题.与扩展的Online Demo #2相比.
答案很长:你在问题中得到的代码确实有效.您可以在此处在线交互式示例中找到示例XML和代码:Online Demo #1 – 它显示了具有不同PHP和LIBXML版本的结果.
码:
$buffer = '<Feed xmlns="http://www.w3.org/2005/Atom" xmlns:yt="http://gdata.youtube.com/schemas/2007">
<entry>
<yt:duration seconds="1870"/>
</entry>
</Feed>';
$xml = new SimpleXMLElement($buffer);
echo "ibxml version: ", LIBXML_DottED_VERSION, "\n";
foreach ($xml->entry as $item)
{
//original comment: how to get seconds?
$namespaces = $item->getNameSpaces(true);
$yt = $item->children($namespaces['yt']);
$seconds = $yt->duration->attributes();
echo $seconds['seconds'], "\n"; // original comment: but doesn't work.
}
echo "done. should read 1870 one time.\n";
结果:
输出为5.3.26,5.4.16 – 5.5.0
ibxml version: 2.9.1
1870
done. should read 1870 one time.
输出为5.3.15 – 5.3.24,5.4.5 – 5.4.15
ibxml version: 2.8.0
1870
done. should read 1870 one time.
输出为5.1.2 – 5.3.14,5.4.0 – 5.4.4
ibxml version: 2.7.8
1870
done. should read 1870 one time.
从这个角度看,一切都很好.由于您没有给出任何具体的错误描述,因此很难说您的案例出了什么问题.您可能正在使用在您提出问题时过时的PHP版本,例如收到致命错误:
Fatal error: Call to undefined method SimpleXMLElement::getNameSpaces()
可能也是由于过时的libxml版本.根据测试,以下libxml版本适用于PHP 5.1.2-5.5.0:
> ibxml版本:2.9.1
> ibxml版本:2.8.0
> ibxml版本:2.7.8