使用具有冒号的PHP添加简单XML元素

I am attempting to add an XML attribute with PHP that contains a colon.

I want it to look like this:

<record xsi:schemaLocation="http://abc.com/abcItem file:///somename.xsd">

I attempted to add the attribute like this:

$record_xml->addAttribute('xsi:schemaLocation','http://abc.com file:///somepath/somename.xsd');

but the resulting XML is:

<record schemaLocation="http://abc.com/abcItem file:///somepath/somename.xsd">

In addition to the namespace prefix (the part before the colon), you must also include the corresponding namespace URI (as the third argument):

$record_xml->addAttribute(
    'xsi:schemaLocation',
    'http://abc.com file:///somepath/somename.xsd',
    'http://www.w3.org/2001/XMLSchema-instance'
);