parsing nested xml using php - php

Question

here's the XML which I'm trying to parse for a while but I'm stuck on nested elements.
<rss xmlns:dc="http://purl.org/dc/elements/1.1/" xmlns:atom="http://www.w3.org/2005/Atom" xmlns:course="https://www.example.org/api/course/elements/1.0/" xmlns:staff="https://www.example.org/api/staff/elements/1.0/" version="2.0">
<channel>
<item>
<title>example.org course feed</title>
<link>https://www.example.org/api/v2/report/course-feed/rss</link>
<description>.org - course catalog feed</description>
<language>en</language>
<course:instructors>
<course:staff>
<staff:name>Mark Moran</staff:name>
</course:staff>
</course:instructors>
</item>
</channel>
how to parse course: instructors, my PHP code is
$rss = simplexml_load_file('https://www.edx.org/api/v2/report/course-feed/rss');
$namespaces = $rss->getNamespaces(true);
foreach ($rss->channel->item as $item) {
$title = $item->title ;
}
EDIT:2
$rss = simplexml_load_file('https://www.example.org/api/v2/report/course-feed/rss');
$namespaces = $rss->getNamespaces(true);//Add this line
foreach ($rss->channel->item as $item) {
$course_title = $item->title ;
$course_description = $item->description;
$course_url = $item->link;
$course = $item->children($namespaces['course']);
$course_thumbnail_url = $course->{'image-thumbnail'};
$course_banner_url = $course->{'image-banner'};
$course_teaser_url = $course->{'video-youtube'};
$course_start_date = $course->start;
$course_duration = $course->length;
$instructors = $item->children('course',true)->instructors;
$staff = $instructors->children('course',true)->staff;
$instructor_name = $staff->children('staff',true)->name;
$instructor_image = $staff->children('staff',true)->image;
echo $instructor_name.' '.$instructor_image,"<br>";
$course_price = 0;
$course_provider_id = 3;
$course_affiliates = $course->school;
$categories = $course->subject;
$categories = explode(',', $categories);
$c = count($categories);
$i = 0;
while($i < $c)
{
$course_rating = mt_rand(3.5,5);
$course_category = $categories[$i];
if(mysqli_query($conn,"INSERT into course_catalog_table (course_title,course_description,course_url,course_thumbnail_url,course_banner_url,course_teaser_url,course_category,course_start_date,course_duration,course_rating,course_affiliates,course_instructor,course_instructor_image,course_price,course_provider_id) VALUES('$course_title','$course_description','$course_url','$course_thumbnail_url','course_banner_url','course_teaser_url','$course_category','$course_start_date','$course_duration','$course_rating','$course_affiliates','$instructor_name',$instructor_image','$course_price')"))
{
echo "successfull\r\n";
}
$i++;
}
}
When i print instructor_name and instructor_image sometimes its prints but sometimes it throws warning that main(): Node no longer exists ,how can i check that is empty or not

Answer 1

You can use the children() function to access the child tree of the xml structure.
Do like this:
$rss->channel->item->children('course',true)->instructors;
Read: http://php.net/manual/en/simplexmlelement.children.php
But since the XML have multiple nest, you need to use multiple children() function to access the deepest nest.
Here is the modified code to parse the XML you give:
foreach ($rss->channel->item as $item)
{
$title = $item->title;
// access course:instructors nest
$instructors = $item->children('course',true)->instructors;
// then access the course:staff nest
$staff = $instructors->children('course',true)->staff;
// finally access the staff:name nest value
$name = $staff->children('staff',true)->name;
// print the value
echo "Staff Name: ". $name . "<br>";
}
Test run: https://eval.in/735810