Description:
------------
xsi:type is not always set for complexTypes.  Notice the absence of
xsi:type="collectionInfo" in the actual output.

Reproduce code:
---------------
<?xml version="1.0" encoding="UTF-8"?>
<xsd:schema xmlns:xsd="http://www.w3.org/2001/XMLSchema">

<xsd:element name="request" type="requestType"/>

<xsd:complexType name="requestType" abstract="true"/>

<xsd:complexType name="collectionInfo">
  <xsd:complexContent>
    <xsd:extension base="requestType">
      <xsd:sequence minOccurs="0" maxOccurs="unbounded">
        <xsd:element name="collection"/>
      </xsd:sequence>
      <xsd:attribute name="kind" type="xsd:string"
fixed="collectionInfo"/>
    </xsd:extension>
  </xsd:complexContent>
</xsd:complexType>

<xsd:element name="request-list">
  <xsd:complexType>
     <xsd:sequence>
        <xsd:element ref="request" minOccurs="0"
maxOccurs="unbounded"/>
     </xsd:sequence>
  </xsd:complexType>
</xsd:element>

</xsd:schema>

<?php
try {
	$xmldas = SDO_DAS_XML::create("request.xsd");
	try {
		$doc = $xmldas->createDocument('', 'request-list');
		$rdo = $doc->getRootDataObject();
		$request = $xmldas->createDataObject('', 'collectionInfo');
		$request->collection->insert('Blah');
		$request->kind = 'collectionInfo';
		$rdo->request->insert($request);
		print($xmldas->saveString($doc));
	} catch (SDO_Exception $e) {
		print($e);
	}
} catch (SDO_Exception $e) {
	print("Problem creating an XML document: " . $e->getMessage());
}
?>

Expected result:
----------------
<?xml version="1.0" encoding="UTF-8"?>
<request-list
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"><request
kind="collectionInfo"
xsi:type="collectionInfo"><collection>Blah</collection></request></reque
st-list>

Actual result:
--------------
<?xml version="1.0" encoding="UTF-8"?>
<request-list
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"><request
kind="collectionInfo"><collection>Blah</collection></request></request-l
ist>

Changing php version.

Matthew, thanks for this. You are right of course. I just tried running
the xml that we generate (the actual) through XERCES and it does not
validate, whereas with the xsi:types (expected) it does. I have emailed
Pete Robbins with the details to see if he wants it turned into a
Tuscany JIRA.

Raised as http://issues.apache.org/jira/browse/TUSCANY-1564

Since the Tuscany issue has been resolved, when can I expect the new
Tuscany code to make it into the php extension?

Matt, you will see that I created release 1.2.3 today and this fix will
be in there.

Thank you for your bug report. This issue has been fixed
in the latest released version of the package, which you can download at
http://pecl.php.net/get/SCA_SDO

Thanks for the quick fix and reply.  Great job!  :-)