Xesam meta-meta-data spec needs attention.

[Evgeny Egorochkin]

On Saturday 12 May 2007 18:02:08 Mikkel Kamstrup Erlandsen wrote:
> > While
> > > this could be done, the machine readable ontology does have quite a few
> > > benefits. Fx:
> > >
> > >  * You could update the ontology without updating any applications or
> >
> > search
> >
> > > engine code
> > >
> > >  * 3rd parties could extend the ontology by installing their own ones
> >
> > Yes, you could update or extend the ontology, but the new fields won't be
> > automatically populated until the engine is told how to get those from
> > the original data.
> > Does this make sense ?
>
> Yes you are entirely right. There are still many reasons to allow for
> extensibility though.
>
> It might be that some search engines will extract more rich data than the
> xesam spec. With easily introspectable fields applications can pick this up
> on the fly.
>
> It has also been discussed several times how to use common metadata
> extractors. If applications could install a special-purpose extractor then
> we also need a way to define new fields...

The idea is that applications will use Xesam API to introspect fields, so to 
them it doesn't matter where field definitions come from, which format etc.
And the question is maybe we should use API to define these fields instead of 
text-files?

like

xesam::field f("music:composer");
f.addParent("content:author");

etc

So each meta-data extractor defines their specific fields via API + xesam core 
defines a set of pre-defined fields to enforce the standard.

--Evgeny