[xsl] Referencing namespace prefixes within an XSD Schema generated by XSL transform

[Matt Zumwalt <matt.zumwalt@xxxxxxxxxxxxxxxxxx>]

Hi all,

Here's hoping there's an obvious answer to this.

I need to generate minimal XSD schemas from data models that are  
defined in XML documents.  I've got everything working except one  
little detail.  I don't know how to reference the generated schema's  
target namespace when I'm defining its elements' types.

Example:  The generated schema defines one complexType named  
"metadataSet".  I want to create an xsd:element with that as its  
type.  In a normal xsd file I would declare a namespace xmlns:tns and  
then set the element's type to "tns:metadataSet".

Here's the gotcha:  I can't declare xmlns:tns up in the  
<xsl:stylesheet> tag because parts of the namespace URI come from my  
source XML file, which means that they are not available until I  
start an <xsl:template> tag.  Within the template, I construct the  
namespace URI and store it as an xsl:param, but this doesn't help  
much.  XSL has this nifty setup with declaring namespaces for  
elements and attributes, but these namespaces get extra little  
inserts like xmlns:ns0 that only appear during the transform  
process.  This leaves me in the lurch because I need to reference  
that namespace when I declare the vale of an attribute.   As far as I  
can tell, there is no way for my xsl document to know exactly what  
that auto-generated namespace prefix will look like in the output  
document.  That would be fine if I only needed to append the prefix  
to attribute and element names because I could basically ignore the  
whole thing and let the processor handle it, but I need to put the  
namespace prefix into the VALUE of a "type" attribute.

There's got to be either a way to:
1) programmatically reference the auto-generated namespace prefixes,
2) stop the processor from generating those little inserts in the  
namespace prefixes, or
3) bypass the whole headache in some way that I didn't notice.


#####
#  My XSL Document (Currently the metadataSet element's type is set  
to "tns:metadataSet", but the tns prefix is not declared anywhere.
####

<?xml version="1.0" encoding="UTF-8"?>
<xsl:stylesheet version="1.0"
	xmlns="http://www.w3.org/2001/XMLSchema";
	xmlns:xsl="http://www.w3.org/1999/XSL/Transform";
	xmlns:xsd="http://www.w3.org/2001/XMLSchema";>
	<xsl:output method="xml" version="1.0" encoding="UTF-8" indent="yes"/>
	<xsl:template match="/">
		<xsl:param name="targetNS">http://www.mediashelf.com/xsd/<xsl:value- 
of select="metadataModel/@owner"/>/<xsl:value-of  
select="metadataModel/@name"/></xsl:param>
		<schema targetNamespace="{$targetNS}">
			
			<complexType name="metadataSet">
				<sequence>
					<xsl:for-each select="metadataModel/metadataElement">
						<element name="{@name}" type="{valueType}" xmlns="http:// 
www.w3.org/2001/XMLSchema"/>
					</xsl:for-each>
				</sequence>
			</complexType>
			
			<element name="metadataSet" type="tns:metadataSet"/>
		
		</schema>
	</xsl:template>

</xsl:stylesheet>



#####
# Example of the (ideal) schema that I want to generate:
####

<?xml version="1.0" encoding="UTF-8"?>
<schema xmlns="http://www.w3.org/2001/XMLSchema";
	targetNamespace="http://www.mediashelf.com/xsd/MSHLF/myModel";
	xmlns:xsd="http://www.w3.org/2001/XMLSchema";
	xmlns:tns="http://www.mediashelf.com/xsd/MSHLF/myModel";>
	
	<complexType name="metadataSet">
        <sequence>
        	<element type="xsd:string" name="myTextField"></element>
        </sequence>
        <attribute name="model" type="xsd:string"></attribute>
	</complexType>

	<element name="metadataSet" type="tns:metadataSet"></element>
</schema>



#####
#	Example of the XML Files that get Transformed
####

<?xml version="1.0" encoding="ISO-8859-1"?>
<?xml-stylesheet type="text/xsl" href="SchemaFromModelDef.xsl"?>
<metadataModel name="myModel" owner="MSHLF"
	xmlns:tns="http://www.mediashelf.com/xsd/ModelDefinitionSchema";
	xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance";
	xsi:schemaLocation="http://www.mediashelf.com/xsd/ 
ModelDefinitionSchema ModelDefinitionSchema.xsd ">
  <metadataElement name="myTextField" type="tns:textfield">
    <label>Text Field Label</label>
    <description>Text Field Description</description>
    <valueType>xsd:string</valueType>
    <defaultValue>Enter something!</defaultValue>
    <valuesUsedToDate>
    	<stringValue>"first value used"</stringValue>
    	<stringValue>"second value used"</stringValue>
    </valuesUsedToDate>
  </metadataElement>
</metadataModel>



Matt Zumwalt
matt.zumwalt@xxxxxxxxxxxxxxxxxx
917-687-8551

Visit http://www.yourmediashelf.com