Parsed XML returns empty array

[cdgn-coding]

I'm getting this XML from an API call,

<cas:serviceResponse xmlns:cas='http://www.yale.edu/tp/cas'> 
  <cas:authenticationFailure code='INVALID_TICKET'> ticket 'ST-29070-02O0Y6LAcOmMC9ytvddU-cas' not recognized </cas:authenticationFailure> 
</cas:serviceResponse>

When I do

$xml = \Parser::xml( $response->getBody() );
dd($xml);

I just get an ampty array: []

Wondering the cause

[danhunsaker]

The XML parser uses SimpleXML to read in the XML data, the does a JSON encode/decode to convert it to a simple array, cleaning up a few special cases in the process. This silently discards namespaced elements, due to how SimpleXML handles array conversion. More detail is available in the PHP docs, though the comment in question is a bit of a rant about how the author thinks this is a bad approach in general.

Short answer: namespaced XML isn't supported.