The default behavior of XML serialization (to_xml) for ActiveRecord objects will emit 'type' and 'nil' attributes that are similar to XML Schema Instance attributes, but aren't set in a XML Namespace.

For example, a model might produce an output like this:

<user>
  <username nil="true" />
  <first-name type="string">Name</first-name>
</user>

Is there anyway to get to_xml to utilize the XML Schema Instance namespace and prefix the attributes and the values?

Using the above example, I'd like to produce the following:

<user xmlns:xsi="http://www.w3.org/1999/XMLSchema-instance" xmlns:xs="http://www.w3.org/1999/XMLSchema">
  <username xsi:nil="true" />
  <first-name xsi:type="xs:string">Name</first-name>
</user>