XALAN register Extension Function like in SAXON

i want to transform a XML by XSLT with XALAN. Now i want to use a extension-function, this function have to be added in JAVA source like in SAXON:

Method:

TransformerFactory tFactory = TransformerFactory.newInstance();
Configuration c = ((net.sf.saxon.TransformerFactoryImpl) tFactory).getConfiguration();
c.registerExtensionFunction(new FooExtension());

FooExtension:

public class FooExtension extends ExtensionFunctionDefinition {

    private static final long serialVersionUID = -8143237239412146617L;

    @Override
    public SequenceType[] getArgumentTypes() {
        return new SequenceType[] { SequenceType.EMPTY_SEQUENCE };
    }

    @Override
    public StructuredQName getFunctionQName() {
        return new StructuredQName("ns", "http://namespace", "generate-guid");
    }
}

But how does it works in XALAN (?FunctionTable?, ?FunctionResolver?, ?URIResolver?) , i have to do it by source, i'm not allowed to add class in XSLT.

Thanks!!

When registering the function in your java code, you still would have to declare the namespace in your stylesheet, don't you? In that case I don't think there is much conceptual difference between doing