Errors in VOTable-1.1.xsd

[Ray Plante]

Hi Francois,

I've had a close look at VOTable-1.1.xsd (which I got from the VOTable
twiki page) to track down some problems we are having incorporating
VOTable into a Web Service (namely, SkyNode).  I have subsequently found
two errors in the schema.  I also found an inconsistancy between the 
prose document and the XSD.  

1. Mixed content for INFO, TD, and COOSYS

The error that was the source of our difficulties has to do with the 
definition of the content for INFO, TD, and COOSYS.  In v1.0, these were 
defined as a mixed type that extended the complex type "anyTEXT":

   <xs:element name="TD">
     <xs:complexType mixed="true"><xs:complexContent>
       <xs:extension base="anyTEXT">                     <!-- here -->
         <xs:attribute name="ref" type="xs:IDREF"/>
       </xs:extension>
     </xs:complexContent></xs:complexType>
   </xs:element>

In v1.1, this was changed to extend "xs:string":

   <xs:element name="TD">
     <xs:complexType mixed="true"><xs:complexContent>
       <xs:extension base="xs:string">                   <!-- Error! -->
         <!-- xs:attribute name="ref" type="xs:IDREF"/ -->
         <xs:attribute name="encoding" type="encodingType"/>
       </xs:extension>
     </xs:complexContent></xs:complexType>
   </xs:element>

This is an error.  When a complex type is declared to have complex 
content, the type given in the base attribute must be a complex type.  
(See http://www.w3.org/TR/xmlschema-0, section 2.5.3; and 
http://www.w3.org/TR/xmlschema-1, section 3.4.3, constraint 1.)  
xs:string, of course, is a simple type. 

I believe the intent for these three elements was to allow them to contain 
an arbitrary mix of child text and elements.  If so, then the simplest 
solution is to change the base type back to "anyTEXT".  I don't know what 
motivated the change to "xs:string".

2.  Pattern for ucdType

In the definition of the simple type "ucdType", the last "-" needs to be 
escaped so not to be interpreted as part of a character range.  That is, 
it should look like this:

 <xs:simpleType  name="ucdType">
   <xs:restriction base="xs:token">
     <xs:pattern  value="[A-Za-z0-9_.,\-]*"/>   <!-- Not "[A-Za-z0-9_.,-]" -->
     </xs:restriction>
 </xs:simpleType>

3.  Inconsistant use of COOSYS attributes in example

In VOTable-1.09.pdf, the example on page 7 shows the COOSYS line:

  <COOSYS ID="J2000" equinox="2000." epoch="2000." system="eq_FK5"/>

However, VOTable-1.1.xsd (as well as the 1.0 version, VOTable.xsd) define 
the types for equinox and epoch to be "astroYear" which must match the 
pattern "[JB][0-9]+([.][0-9]*)?".  Thus, the example should look like 
this:

  <COOSYS ID="J2000" equinox="J2000." epoch="J2000." system="eq_FK5"/>

(FYI, the same inconsistancy existed in the 1.0 versions as well.)

I'm still testing, but I believe that correcting (1) will remove the last 
stumbling block to straight-forward integration of VOTable with Web 
Services. 

thanks,
Ray