From: Hart, Lewis (lhart@grci.com)
Date: 06/28/01
-----Original Message-----
From: Marin Dimitrov [mailto:marin.dimitrov@sirma.bg]
Sent: Thursday, June 28, 2001 8:22 AM
To: daml-help@daml.org; maria@grci.com
Subject: DAML API usage
>
>Hi,
>
>What is the correct sequence of API calls for creating an ontology from
>scratch and exporting it in RDFS?
>
>The following fragment is not working:
>
>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>
>
> DAMLOntology coreOntology = new DAML(new
>DAMLOntologyImp(DAML.DAML_URI));
> DAMLOntology ewnOntology = new DAMLOntologyImp();
> ewnOntology.addImport(coreOntology);
>
> DAMLClass classTop = ewnOntology.createClass("Top");
> classTop.addSubClassOf(DAML.Class);
>
> DAMLClass class1 = ewnOntology.createClass("FirstOrderEntity");
> class1.addSubClassOf(classTop);
>
> DAMLClass class2 = ewnOntology.createClass("SecondOrderEntity");
> class2.addSubClassOf(classTop);
>
> ..........
>
> Model m = ewnOntology.toRDFModel();
> RDFUtil.dumpModel(m,
> System.out,
>
>(RDFSerializer)Class.forName("org.w3c.rdf.implementation.syntax.sirpac.SiRS
"
>).newInstance());
>
> ..........
>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>
>
The above code is correct. You have found a (rather obvious) bug in the
toRDFModel code, a fix will be posted later today.
>
>
>The output looks like:
>
>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>
>
><?xml version='1.0' encoding='ISO-8859-1'?>
><!DOCTYPE rdf:RDF [
> <!ENTITY rdf 'http://www.w3.org/1999/02/22-rdf-syntax-ns#'>
> <!ENTITY a 'http://www.daml.org/2001/03/daml+oil#'>
> <!ENTITY b ''>
>]>
><rdf:RDF xmlns:rdf="&rdf;"
> xmlns:a="&a;"
> xmlns:b="&b;">
><a:Class rdf:about="FirstOrderEntity"/>
><a:Class rdf:about="SecondOrderEntity"/>
><a:Class rdf:about="Top"/>
></rdf:RDF>
>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>
>
>
>i.e. the subClassOf relations are missing - in fact the RDFS namespace in
>not referenced at all, and additionally there exists a namespace "b" which
>is never used.
The RDFS namespace is not used, because the DAML+OIL resouces are used where
applicable. That is, daml:Class rather than rdfs:class. After all, this is a
DAML ontology.
I don't know where the extra null namespace, in this case "b", is comming
from. It does no harm so it is a low priority.
>
>The API docs and samples are not that helpful so I'll appreciate any hints
Sorry about that. I know one thing that is missing is that there is no
example of building an ontology programmatically. That is coming shortly. Do
you have any specific comments?
>
>thanx,
>
> Marin
>
>----
>"When someone is seeking, it happens quite easily that he only sees
>the thing that he is seeking; that he is unable to find anything, unable to
>absorb anything, because he is only thinking of the thing he is seeking,
>because he is obsessed with his goal. Seeking means: to have a goal;
>but finding means: to be free, to be receptive, to have no goal. ..."
>
>
> Herman Hesse, "Siddhartha"
>
>
>
>
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