using namespaces in xmlschema

Hi,

I am trying to use namespaces within xmlschema. The idea is that editors
of instances
of this schema do not have to use prefixes for namespaces, since these
are already 
described in the schema. However, if I try to do this, it turns out that
I stil have
to use prefixes for namespaces in my instance document. Below is a small
example (part
of schema and instance document). In the schema I import a schema
related to a namespace.
Within the type definition of materialfraction I use this namespace to
indicate that
it should use a structure defined in the schema associated with this
namespace.
I thought this would give enough information not to use namespaces in
the instance
document. However, I still have to declare a namespace for this element
(see instance part).
Is there a way to use namespaces in schemas and avoid them in instance
documents?

-----snippet of an xml schema I use:

<?xml version="1.0"?>
<xsd:schema xmlns:xsd="http://www.w3.org/2001/XMLSchema"
            targetNamespace="http://www.cern.ch/DDLMaterial"
            xmlns="http://www.cern.ch/DDLMaterial"
            xmlns:DDLReference="http://www.cern.ch/DDLReference"
            elementFormDefault="unqualified">

<!-- Importing  -->

<xsd:import namespace="http://www.cern.ch/DDLReference"
            schemaLocation="DDLReference.xsd" />


<!-- Element definitions -->

<xsd:element name="MaterialFraction" type="MaterialFractionType"/>



<!-- Type definitions -->

<xsd:complexType name="MaterialFractionType">
  <xsd:sequence>
      <xsd:element ref="DDLReference:rMaterial" minOccurs='1'
maxOccurs='1'/>
  </xsd:sequence>
  <xsd:attributeGroup ref="MaterialFractionAttributes"/>
</xsd:complexType>


<!-- Attribute definitions -->


<xsd:attributeGroup name="MaterialFractionAttributes">
   <xsd:attribute name="fraction" type="xsd:float" use="required"/>
</xsd:attributeGroup>

</xsd:schema>

----------------------snippet of instance document based on this schema
<?xml version="1.0"?>
<CompositeMaterial xmlns="http://www.cern.ch/DDLMaterial"
                       
xmlns:DDLReference="http://www.cern.ch/DDLReference"
                       
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
                        xsi:schemaLocation=
                            "http://www.cern.ch/DDLMaterial
DDLMaterial.xsd
                             http://www.cern.ch/DDLReference
DDLReference.xsd"
                        name="testmat" ID="12" symbol="te"
method="mixture by weight">
   <Density value="1.2" units="g/cm^3"/>
   <MaterialFraction fraction="0.4">
       <DDLReference:rMaterial name="testref"
url="http://www.cern.ch/somewhere.xml"/>
   </MaterialFraction>
   <MaterialFraction fraction="0.3">
       <DDLReference:rMaterial name="testref1"
url="http://www.cern.ch/somewhere.xml"/>
   </MaterialFraction>
</CompositeMaterial>


----------------------------------

Frank van Lingen

Received on Monday, 24 September 2001 11:28:05 UTC