Parent/Child relationship in AXIS

["Sapozhnikov, Michael" <ms...@axsone.com>]

Hi,

I have a general question regarding generated XML in case when xsd extension
is used.

I have my types defined as follows:

	<element name="Step" type="tns:ScriptFormType" abstract="true"/>

  	<complexType name="ScriptFormType">
    	     <sequence>
      		<element name="FUNCTION" type="integer"/> 
      		<element name="SelectedRow" type="nonNegativeInteger"/>
    	     </sequence>
  	</complexType>

	<element name="STEP_KS1" type="tns:ComplistStepKS1"
substitutionGroup="tns:Step"/>

     	<complexType name="ComplistStepKS1">
       	     <complexContent>
         		<extension base="tns:ScriptFormType">
           	   	     <sequence>
            		<element name="FORM" type="string" />
             		<element name="FIELDS" type="my_other_type"/>
           		     </sequence>
         		</extension>
       	     </complexContent>
     	</complexType>    

I am talking not about generated child class, but about actual message on
the wire.
I have the message, captured by tcpmon:

    <ns7:Step xsi:type="ns6:ComplistStepKS1" 
	xmlns:ns6="http://localhost/ctron/exec/schemas/csuvscni/complist" 
	xmlns:ns7="http://localhost/ctron/exec/schemas/AppGlobals">
        <FORM>KS1</FORM>
        <FIELDS>
             <COMPNUM>999</COMPNUM>
             <SRCCODE>AAA</SRCCODE>
        </FIELDS>
        <ns7:SelectedRow>0</ns7:SelectedRow>
        <FUNCTION>32</FUNCTION>
    </ns7:Step>

ComplistStepDS1 is the subclass of ScriptFormType, and as I understand
parent class should be initialized first and its fields should appear before
child fields in XML message. So I really expect it to be like this, because 

    <ns7:Step xsi:type="ns6:ComplistStepKS1" 
	xmlns:ns6="http://localhost/ctron/exec/schemas/csuvscni/complist" 
	xmlns:ns7="http://localhost/ctron/exec/schemas/AppGlobals">
        <FUNCTION>32</FUNCTION>
        <ns7:SelectedRow>0</ns7:SelectedRow>
        <FORM>KS1</FORM>
        <FIELDS>
             <COMPNUM>999</COMPNUM>
             <SRCCODE>AAA</SRCCODE>
        </FIELDS>
     </ns7:Step>

Am I right or wrong? Should Parent/Child relationship be reflected in XML
message itself? 
I don't think this message could be validated ( I am not validating it right
now).
Is this expected behavior and does this happen only in AXIS? 


Thanks,
Michael