RWP04: Registry Replication

[Elizabeth Auden]

Hi all,

> registry query schema. Tony, Elizabeth and I have been working on
> something similar(!) for AstroGrid and whilst we don't yet have schema,
> we have a simple example XML query (below) upon which I would welcome
> everyone's comments.

Here's the current draft of the astrogrid registry query schema that
matches up with Keith's query example (schema is pasted under the query).
Still evolving, so comments welcome.

cheers,
Elizabeth

> <query>
>    <selectionSequence>
>       <selection>
>          <item>type</item>
>          <value>white dwarf star</value>
>       </selection>
>       <operator>AND</operator>
>       <selectionSequence>
>          <selection>
>             <item>wavelength</item>
>             <value>optical</value>
>          </selection>
>          <operator>OR</operator>
>          <selection>
>             <item>wavelength</item>
>             <value>uv</value>
>          </selection>
>       </selectionSequence>
>       <operator>AND</operator>
>       <selectionSequence>
>          <selection>
>             <item>keyword</item>
>             <value>BPM 16274</value>
>          </selection>
>          <operator>OR</operforator>
>          <selection>
>             <item>keyword</item>
>             <value>GD 50</value>
>          </selection>
>          <operator>OR</operator>
>          <selection>
>             <item>keyword</item>
>             <value>HST photometric standards</value>
>          </selection>
>       </selectionSequence>
>    </selectionSequence>
> </query>

QUERY SCHEMA:

<?xml version="1.0" encoding="UTF-8"?>
<xs:schema xmlns:xs="http://www.w3.org/2001/XMLSchema">
  <xs:element name="selection">
     <xs:complexType>
        <xs:sequence>
           <xs:element maxOccurs="1" minOccurs="1" name="item" type="xs:string"/>
           <xs:element maxOccurs="1" minOccurs="1" name="value" type="xs:string"/>
        </xs:sequence>
     </complexType>
  </xs:element>
  <xs:element name="operator">
     <xs:complexType>
        <xs:choice>
           <xs:element maxOccurs="1" minOccurs="0" ref="AND"/>
           <xs:element maxOccurs="1" minOccurs="0" ref="OR"/>
           <xs:element maxOccurs="1" minOccurs="0" ref="NOT"/>
        </xs:choice>
     </xs:complexType>
  </xs:element>
  <xs:element name="selectionSequence">
     <xs:complexType>
        <xs:sequence>
           <xs:element maxOccurs="unbounded" minOccurs="1" ref="selection"/>
           <xs:element maxOccurs="unbounded" minOccurs="0" ref="operator"/>
        </xs:sequence>
     </xs:complexType>
  </xs:element>
  <xs:element name="query">
     <xs:complexType>
        <xs:sequence>
           <xs:element maxOccurs="unbounded" minOccurs="1" ref="selectionSequence"/>
        </xs:sequence>
     </xs:complexType>
  </xs:element>
</xs:schema>