Adding Prefix / Namespace to XML

Question

I have generated a simple xml. I want to add namespace / prefix in the xml is there a way using php DomDocument. Or do I need to use core php to replace the tags and recreate it in xml.

<?xml version="1.0" encoding="UTF-8"?>
<orderShipment>
    <orderData>
        <productId>1</productId>
        <orderStatus>
            <status>Shipped</status>
            <statusQuantity>
                <amount>1</amount>
            </statusQuantity>
            <trackingInfo>
                <shipDateTime>Fri, 24 Feb 2017</shipDateTime>
                <carrierName>UPS</carrierName>
                <methodCode>Standard</methodCode>
                <trackingNumber>123123123</trackingNumber>
                <trackingURL>http://ups.com</trackingURL>
            </trackingInfo>
        </orderStatus>
    </orderData>
</orderShipment>

Expected Output

<?xml version="1.0" encoding="UTF-8"?>
<ns2:orderShipment>
    <ns2:orderData>
        <ns2:productId>1</ns2:productId>
        <ns2:orderStatus>
            <ns2:status>Shipped</ns2:status>
            <ns2:statusQuantity>
                <ns2:amount>1</ns2:amount>
            </ns2:statusQuantity>
            <ns2:trackingInfo>
                <ns2:shipDateTime>Fri, 24 Feb 2017</ns2:shipDateTime>
                <ns2:carrierName>UPS</ns2:carrierName>
                <ns2:methodCode>Standard</ns2:methodCode>
                <ns2:trackingNumber>123123123</ns2:trackingNumber>
                <ns2:trackingURL>http://ups.com</ns2:trackingURL>
            </ns2:trackingInfo>
        </ns2:orderStatus>
    </ns2:orderData>
</ns2:orderShipment>

Answer 1

Use the DOMDocument::createElementNS() method.

$namespaceUri = 'http://www.ups.com/WSDL/XOLTWS/Track/v2.0';

$document = new DOMDocument();
$order = $document->appendChild(
  $document->createElementNS($namespaceUri, 'ns2:orderShipment')
);
$order->appendChild(
  $document->createElementNS($namespaceUri, 'ns2:orderData')
);

$document->formatOutput = TRUE;
echo $document->saveXml();

Output:

<?xml version="1.0"?>
<ns2:orderShipment xmlns:ns2="http://www.ups.com/WSDL/XOLTWS/Track/v2.0">
  <ns2:orderData/>
</ns2:orderShipment>

*NS are the namespace aware variants of the DOM methods. Usually they will take the namespace uri as the first argument. The namespace prefix will only be used in "write/setter" methods.