Question

I seem to be getting back a well-formed XML document from this cURL, but I can’t seem to parse this return using the SimpleXMLElement class. This is the iteration of code that I’m working with now:

$url = "http://rosemary.umw.edu/~stephen/cpsc448/numCredits.php?prefix=". $prefix ."&number=" . $number; // prefix=cpsc&number=220
$ch = curl_init();
curl_setopt ($ch, CURLOPT_URL, $url);
curl_setopt ($ch, CURLOPT_RETURNTRANSFER, 1);
curl_setopt($ch, CURLOPT_HEADER, false);
curl_setopt ($ch, CURLOPT_CONNECTTIMEOUT, 15);

$resp = curl_exec($ch);

echo $resp;

This returns:

<?xml version="1.0"?><NumCredits>4</NumCredits>

This is how I’m currently trying to parse the return:

$xml = new SimpleXMLElement($resp);
echo $xml->NumCredits[0];

Using this I don’t get a response. I’ve also tried this method without success:

$dom = new DOMDocument;
$dom->loadXML($resp);
if (!$dom) {
    echo 'Error parsing document';
    exit;   
}

$simpleXML = simplexml_import_dom($dom);
echo $simpleXML;
return $simpleXML->NumCredits[0];

I have to be doing something wrong here but I can’t quite figure out why it’s so hard to parse this return.

Answer 1

You only have one element in your XML, so it is considered the document root:

$xml_string = '<?xml version="1.0"?><NumCredits>4</NumCredits>';
$xml = new SimpleXmlElement($xml_string);
print_r($xml);

Will output:

SimpleXMLElement Object
(
    [0] => 4
)

Thus it can be accessed as $xml[0];

If you want to be able to access it by the element name, you will need to add a root element to your XML, for example:

<?xml version="1.0"?>
<root>
    <NumCredits>4</NumCredits>
</root>

Once this document is parsed, you can access the value using $xml->NumCredits;