XML Schema Support

9.0D

The structure of a XFILE is controlled by an internal schema. This schema is a limited subset of the XML Schema definition and is created implicitly when XML data is loaded.

Note the following:

1. The internal schema can also be created by loading an external schema. Not all information contained in an external schema will be retained in the internal schema. Any comments and the following XML schema keywords will be ignored when loading an external XML schema:

 

     xs:field

     xs:key

     xs:keyref

     xs:selector

     xs:unique

 

2. The following the XML schema keywords are not supported and will cause a error during the load process:

 

     xs:anyAttribute

     xs:complexContent

     xs:extension

     xs:import

     xs:include

     xs:list

     xs:notation

     xs:redefine

     xs:simpleContent

     xs:union

 

3. The internal schema is updated during all I/O operations on the XFILE.

4. The internal schema is currently not used to verify data on either input or output of the XML file, just to verify structure.

5. A number of options exist to control the operation of the internal schema.

6. If a field name is written or updated that is not in the internal schema, that field name will be added to the schema. To prevent this and cause an error, the XFILE_CLOSEDSCHEMA flags can be used.

7. The internal schema can be stored on disk by setting the XFILE_WRITESCHEMA flag, setting the name of the physical XML schema file, and performing a FLUSH operation.

See Also: XML Support