读取xml文件属性

Question

我正在尝试从 url 读取 rss 提要，我成功获得了标题、描述等。
现在我在阅读属性信息时遇到了问题。
我的xml是这样的：

<item>
<guid>https://www.edx.org/node/22726</guid>
<title>Managing Projects with Microsoft Project</title>
<link>
 https://www.edx.org/course/managing-projects-microsoft-project-microsoft-cld213x
</link>
<description>
 Want to master project management? Have a project to manage but unsure where to begin? With over 20 million users, Microsoft Project is the go to app for project managers. 
</description>
<pubDate>Wed, 06 Jul 2016 16:21:40 -0400</pubDate>
<course:id>course-v1:Microsoft+CLD213x+2T2016</course:id>
<course:code>CLD213x</course:code>
<course:created>Thu, 16 Jun 2016 14:59:55 -0400</course:created>
<course:start>2016-07-11 00:00:00</course:start>
<course:end>2016-12-31 00:00:00</course:end>
<course:self_paced>0</course:self_paced>
<course:length>6 modules</course:length>
<course:prerequisites>
 Basic project management knowledge and skills Basic knowledge and skills using any current Windows® operating system (preferably Windows 10) Competency in using other Microsoft® Office® applications (preferably Office 2016)
</course:prerequisites>
</item> 

我可以轻松访问标题、描述、发布日期等，但在访问<course:length> <course:id> <course:image-banner> etc 时遇到问题

我的php代码是

<?php
 $rss = simplexml_load_file('https://www.example.org/api/v2/report/course-feed/rss');
echo '<h1>'. $rss->channel->title . '</h1>';
foreach ($rss->channel->item as $item) {
 echo '<h2><a href="'. $item->link .'">' . $item->title . "</a></h2>";
 echo "<p>" . $item->pubDate . "</p>";
 echo "<p>" . $item->description . "</p>";

} ?>

Answer 1

这是一个命名空间问题！首先，您的文档必须具有xmlns:course="//URL" 属性。然后你可以像这样访问你的<course:*>：

$rss = simplexml_load_file('https://www.example.org/api/v2/report/course-feed/rss');
$namespaces = $rss->getNamespaces(true);//Add this line
echo '<h1>'. $rss->channel->title . '</h1>';
foreach ($rss->channel->item as $item) {
     echo '<h2><a href="'. $item->link .'">' . $item->title . "</a></h2>";
     echo "<p>" . $item->pubDate . "</p>";
     echo "<p>" . $item->description . "</p>";

     $course = $item->children($namespaces['course']);
     echo $course->id;
     echo $course->prerequisites;
}