How to load xml data with namespace - php

Question

So the XML I am trying to load looks something like this:
<tns:PersonListOutput xmlns:tns="http://www.example.com/api/person">
<tns:LastName>Doe</tns:LastName>
<tns:TransmissionDate>2018-03-02T10:16:23</tns:TransmissionDate>
<tns:People>
<tns:Person>
<tns:Name>John Doe</tns:Name>
<tns:RevisionDate>2017-08-10T01:45:40</tns:RevisionDate>
</tns:Person>
<tns:Person>
<tns:Name>Jane Doe</tns:Name>
<tns:RevisionDate>2017-08-10T01:45:43</tns:RevisionDate>
</tns:Person>
</tns:People>
</tns:PersonListOutput>
I am loading this data from a URL using the following code:
$response_xml_data = file_get_contents($URL);
$data = simplexml_load_string($response_xml_data);
I was finally able to reference the top level properties but am unable to get the properties of the Person. This is how I finally got it working if someone could help with the Person access or suggest a better way to do it.
$data->registerXPathNamespace('tns', 'http://www.example.com/api/person');
$LastName = $data->xpath('//tns:LastName ');
$TransmissionDate = $data->xpath('//tns:TransmissionDate');
echo $LastName[0];
echo "<br/>";
echo $TransmissionDate[0];

Answer 1

You need to keep prepending the namespace to your XPath query elements, like so:
//tns:People/tns:Person/tns:Name
That will give you all the Name elements inside Person, inside People.
$data = simplexml_load_string($response_xml_data);
$data->registerXPathNamespace('tns', 'http://www.example.com/api/person');
$LastName = $data->xpath('//tns:LastName ');
$TransmissionDate = $data->xpath('//tns:TransmissionDate');
$people = $data->xpath('//tns:People/tns:Person/tns:Name');
var_dump($people);
Demo
Result
array (size=2)
0 =>
object(SimpleXMLElement)[4]
public 0 => string 'John Doe' (length=8)
1 =>
object(SimpleXMLElement)[5]
public 0 => string 'Jane Doe' (length=8)