On Fri, Jan 21, 2011 at 2:39 PM, Andy Seaborne < [email protected]> wrote:
> > > On 20/01/11 15:56, Reto Bachmann-Gmuer wrote: > >> Hi >> >> It retreives the map and then asks for the set of entries. So it seems >> there's no way to bind it to a service, it wants to know all possible >> bindings before it starts. >> >> I created JENA-31 to have a more felxible support here. >> >> Cheers, >> reto >> > > Why not override the other methods? - presumable it's calling > getNsPrefixMap. > > The contract to the writer (and this applies to all writers, not just > RDF/XML) is "here's some prefixes, here's some RDF, go write stuff as best > you can". Yes, currently it needs the finite set of prefix-mappings, JENA-31 the contact is generalied to "here's something that delivers prefixes for URIs, here some RDF, go...". This allows to pass in a map as this is possible now, but also a service that consults a huge database or does some complicated magic to generate a prefix suggestion. > Adding calls into the application for decisions still requires application > code. > > RDF/XML is special because to write properties in RDF/XML requires an XML > namespace. Other formats do not need any prefixes to write legal output and > would be greatly complicated to have > > Prefixes often get set because they are in the input. Carrying them around > is convenient and (as we have found) expected by users even if not used. > > For the specific use case in Clerezza, > > 1/ Layer the problem. > > Why not look through the model, decide the prefixes you do want, then set > the prefix mapping for model and then write it. This gives the application > (i.e. Clerezza) a chance to influence the choices. > In Clerezza we have a service that delivers CURIE-prefixes, this should be sued by serializers > > 2/ Set the prefixes when the data is created - this seems to me to be the > more natural point to make choices. > The Clerezza storage abstraction is based on the RDF abstract syntax which doesn't know about prefixes. So while the CURIE prefix service might learn from the prefixes used in incoming data, the prefixes should not be tied to the data in which they were used. Reto > > > >> >> On Thu, Jan 20, 2011 at 4:33 PM, Chris Dollin >> <[email protected]>wrote: >> >> On Thursday, January 20, 2011 03:00:26 pm Reto Bachmann-Gmuer wrote: >>> >>>> Hello >>>> >>>> I'm trying to connect the jena serializers to a service that delivers >>>> curie-prefix suggestions for uri-prefixes. >>>> >>>> My fisrt attempt doesn't seem to work: >>>> >>>> Model model = ModelFactory.createModelForGraph(graph); >>>> model.setNsPrefixes(new PrefixMappingImpl() { >>>> >>>> @Override >>>> protected String get(String prefix) { >>>> System.out.println("getting "+prefix); >>>> return super.get(prefix); >>>> } >>>> >>>> @Override >>>> public String getNsURIPrefix(String uri) { >>>> System.out.println("getting prefix for "+uri); >>>> if ("http://example.org/".equals(uri)) { >>>> return "ex"; >>>> } >>>> return null; >>>> } >>>> >>>> }); >>>> RDFWriter writer = model.getWriter(jenaFormat); >>>> writer.write(model, serializedGraph, ""); >>>> >>>> the overwritten methods seem not be called. The examples I found all >>>> deal >>>> with registering individual prefix-mappings, in my case I want to access >>>> >>> a >>> >>>> service that suggests a prefix. >>>> >>> >>> The RDF/XML writer calls getNsPrefixMap() to get the entire prefix >>> mapping >>> as a map and then fiddles with that, so, you're right: the methods you >>> wrote are not called. >>> >>> Chris >>> >>> -- >>> "We try our best to make it sound nice." /Hatfield and the >>> North/ >>> >>> Epimorphics Ltd, http://www.epimorphics.com >>> Registered address: Court Lodge, 105 High Street, Portishead, Bristol >>> BS20 >>> 6PT >>> Epimorphics Ltd. is a limited company registered in England (number >>> 7016688) >>> >>> >>
