Re: [PyWrapper-devel] Valid response model

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good investigation roger,
it looks just like you say. I will try to fix it to work with =20
attributes. Will be back in some minutes....
markus

On Dec 15, 2006, at 5:32 PM, Roger Hyam wrote:

> Thanks for the kind words Markus. I'm glad some one is glad I am =20
> trying to do this ;) I hope it doesn't end up with too much work =20
> for you.
>
> I have narrowed down this problem to a simple test case.
>
> This is a more simple XSD with a single import and it works fine:
>
> http://localhost:8080/pywrapper/pywrapper?op=3Dschema&location=3Dhttp://=
=20
> rs.tdwg.org/ontology/voc/xsd/test1.xsd
>
> The second version is just the same but includes the use of an =20
> attribute reference in the imported file:
>
> http://localhost:8080/pywrapper/pywrapper?op=3Dschema&location=3Dhttp://=
=20
> rs.tdwg.org/ontology/voc/xsd/test1_broken.xsd
>
> and it doesn't work!
>
> Looking at the logs
>
> The error message is
>
> "PyWrapperError: Global element reference 'http://rs.tdwg.org/=20
> ontology/voc/Test2#/rdf:about' missing"
>
> But we have a slightly earlier log message saying
>
> 2006-12-15 16:14:14,789 - DEBUG from pywrapper.model: =20
> self._globalRefs=3D[u'http://www.w3.org/1999/02/22-rdf-syntax-ns#/=20
> @about', u'http://rs.tdwg.org/ontology/voc/Test2#/MyElement', =20
> u'http://www.w3.org/1999/02/22-rdf-syntax-ns#/RDF', u'http://=20
> www.w3.org/1999/02/22-rdf-syntax-ns#/MyRdfString']
>
> So it looks to me like it is just getting the namespace of the =20
> attribute reference wrong and so not finding it in the globalRefs =20
> look up. It does it right for the element but not for the attribute.
>
> Looking at the code for _buildAttribute(self, attrs) on line 269 in =20=

> structure_handler.py  it  doesn't mention namespace (unlike the =20
> _buildElement attribute) and it confuses me as it seems to pass the =20=

> type as the namespace to the Attribute object it creates.
>
> Now this code all looks like clever stuff and I don't want to go =20
> trying to fix anything when I don't really know what I am doing - =20
> though I will have a go if no one else wants to. You may be able to =20=

> fix this in minutes rather than my hours and would probably create =20
> fewer bugs .
>
> It may be that I am doing something bad in the XSD although I am =20
> pretty confident I am OK on that.
>
> Would once again be grateful for you comments,
>
> Roger
>
>
>
>
> On 14 Dec 2006, at 10:48, Markus D=F6ring wrote:
>
>> Hi Roger,
>> that's exactly what we were all thinking of doing for some time =20
>> already. Good finally someone DOES it!
>> The xml schema parser inside pywrapper is a custom implementation. =20=

>> I couldnt find any existing schema parser out there, honestly. So =20
>> as you can imagine this is a pretty tough job and I have tried it =20
>> with many different schemas and progressed in implementing xml =20
>> schema, but still dont support all of it (for example references =20
>> and patterns).
>>
>> Well, and your RDF schema is honestly the most complex I've seen =20
>> that was fed to pywrapper.
>> So I tried to trace the problem and as you see pywrapper =20
>> complaints that the attribute  http://rs.tdwg.org/ontology/voc/=20
>> TaxonName#/rdf:about  is being referenced, but is nowhere defined.
>> pywrapper expands all namespace prefixes into the full namespace. =20
>> So in this case http://rs.tdwg.org/ontology/voc/TaxonName# is the =20
>> targetnamespace of the imported lib/TaxonName.xsd schema file. So =20
>> in there I suspect is a reference to rdf:about, which pywrapper =20
>> thinks is an attribute name. I think this is because I cant find =20
>> anywhere the prefix rdf: being defined properly. I suspect oXygen =20
>> and alike know what rdf: means. So try to add a namespace =20
>> declaration to the schemas (for owl etc too). Then pywrapper =20
>> should expand rdf:about into the full qualified name http://=20
>> www.w3.org/1999/02/22-rdf-syntax-ns#about and hopefully find the =20
>> global declaration of rdf:about in the lib/rdf.xsd schema.
>>
>> But again, I think I've never tried a schema with that many =20
>> namespaces and imports so I keep my fingers crossed...
>>
>> Please let me know what happens!
>> Markus
>>
>>
>>
>> On Dec 13, 2006, at 11:29 PM, Roger Hyam wrote:
>>
>>> Hi All,
>>>
>>> I am looking at what TAPIR output models I could use with =20
>>> PyWrapper. I have developed XML Schemas that will help produce =20
>>> valid RDF instance data for a simple OWL ontology. Here is an =20
>>> example:
>>>
>>> http://rs.tdwg.org/ontology/voc/xsd/TaxonName/schema.xsd
>>>
>>> If you open this link in OxygenXML or Spy you can expand all the =20
>>> nodes and create instance documents that look like valid RDF. =20
>>> Here is an example instance document:
>>>
>>> http://rs.tdwg.org/ontology/voc/xsd/TaxonName/template.xml
>>>
>>> So the plan would be to use the schema above (or something =20
>>> similar) as the structure in an output model so that a TAPIR =20
>>> response could be a valid semantic web document and a LSID =20
>>> metadata response. A complete LSID authority would need very =20
>>> little code on top of this.
>>>
>>> The downside is that these schemas are complex because of the =20
>>> number of imports required to support the different namespaces =20
>>> involved.
>>>
>>> Anyhow. The first step was to check that PyWrapper would parse =20
>>> schemas like the one above so I did this:
>>>
>>> http://localhost:8080/pywrapper/pywrapper?=20
>>> op=3Dschema&location=3Dhttp://rs.tdwg.org/ontology/voc/xsd/TaxonName/=20=

>>> schema.xsd
>>>
>>> on my local machine and got
>>>
>>> "The models response structure is invalid: Global element =20
>>> reference 'http://rs.tdwg.org/ontology/voc/TaxonName#/rdf:about' =20
>>> missing"
>>>
>>> I am not sure why I get this as OxygenXML doesn't have a problem =20
>>> with expanding the links and validating the rdf:about attribute =20
>>> so I *think* the schema is OK. The parser is handling the import =20
>>> of TaxonName.xsd OK. Is it a problem with attributes? Is it a bug =20=

>>> or a known limitation or an error in my schema?
>>>
>>> The are also problems with the group element but I can always =20
>>> work round this by just repeating the element.
>>>
>>> Any ideas on the rdf:about problem would be most welcome.
>>>
>>> Many thanks,
>>>
>>> Roger
>>>
>>>
>>>
>>>
>>>
>>> ****************************************
>>>   Roger Hyam <ro...@td...>
>>>   Biodiversity Information Standards
>>> ****************************************
>>>
>>>
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