[mdr-users] Re: XML Namespaces and Custom Metamodels

I may have been too fast by assuming that the exception was caused by
an XML namespace problem.  In fact, I now believe that the XMI reader
(XML parser) is looking for elements in the default (nameless)
namespace and cannot find elements like "tracing.Node".  I'm not sure
why the parser complains about an unknown "package" instead of an
unknown "element" though...

Keep in touch,
Pieter.

On 8/4/05, Pieter Van Gorp <[email protected]> wrote:
> Hi all,
> how can I set the XML namespace to be used in the XMI for models
> conforming to my own metamodel?
> 
> I've created a metamodel for creating traceability links across UML
> models.  Therefore, my metamodel clusters the UML metamodel (more info
> on http://www.fots.ua.ac.be/motmot/docs/traceability-p3.php).  The
> problem is that when I serialize a traceability model to XMI, only
> "UML" is defined as an XML namespace and "tracing" (which should be
> the namespace for elements in the clustering model) is undefined.
> 
> This leads to exceptions when the XMI is read in again.  For example:
> org.netbeans.lib.jmi.util.DebugException: Element name cannot be
> resolved, unknown package: tracing.Node
>         at org.netbeans.lib.jmi.xmi.XmiContext.resolveElementName(XmiContext.java:527)
>         at org.netbeans.lib.jmi.xmi.XmiElement$Content.startSubElement(XmiElement.java:354)
>         at org.netbeans.lib.jmi.xmi.XmiSAXReader.startElement(XmiSAXReader.java:223)
> 
> XMI of the erraneous traceability model:
> <?xml version = '1.0' encoding = 'ISO-8859-1' ?>
> <XMI xmi.version = '1.2' xmlns:UML = 'org.omg.xmi.namespace.UML'
> timestamp = 'Thu Aug 04 15:51:23 CEST 2005'>
>   <XMI.header>
>     <XMI.documentation>
>       <XMI.exporter>Netbeans XMI Writer</XMI.exporter>
>       <XMI.exporterVersion>1.0</XMI.exporterVersion>
>     </XMI.documentation>
>   </XMI.header>
>   <XMI.content>
>     <tracing.Node xmi.id = 'a1' role = 'reference to a1'>
>       <tracing.Node.trace>
>         <tracing.Trace xmi.idref = 'a2'/>
>       </tracing.Node.trace>
>       <tracing.Node.content>
>         <UML:Attribute xmi.idref = 'a3'/>
>       </tracing.Node.content>
>     </tracing.Node>
>     <tracing.Node xmi.id = 'a4' role = 'reference to a2'>
>       <tracing.Node.trace>
>         <tracing.Trace xmi.idref = 'a2'/>
>       </tracing.Node.trace>
>       <tracing.Node.content>
>         <UML:Attribute xmi.idref = 'a5'/>
>       </tracing.Node.content>
>     </tracing.Node>
>     <tracing.Trace xmi.id = 'a2'>
>       <tracing.Trace.node>
>         <tracing.Node xmi.idref = 'a1'/>
>         <tracing.Node xmi.idref = 'a4'/>
>       </tracing.Trace.node>
>     </tracing.Trace>
>   </XMI.content>
> </XMI>
> I thought it may be due to a missing tag in the specification of my
> metamodel but couldn't find a solution on the website for the UML
> profile for MOF...
> 
> Thanks in advance for your help,
> --
> Pieter Van Gorp
>        Teaching and Research Assistant
>        FOrmal Techniques in Software engineering (FOTS)
>        University of Antwerp
>        Middelheimlaan 1
>        2020 Antwerpen - Belgium
>        Office: G.304
>        Phone: +32 3 265 38 71
>        Fax: +32 3 265 37 77
>        http://www.fots.ua.ac.be/~pvgorp/research/
>        http://motmot.sourceforge.net/
>