Re: [Tracker] Result of GetMetadata DBUS Method

[Adrien Bustany <abustany gnome org>]

Le Sun, 18 Sep 2011 12:33:13 -0400,
Nikolaus Rath <Nikolaus rath org> a écrit :

> Adrien Bustany <abustany-rDKQcyrBJuzYtjvyW6yDsg public gmane org>
> writes:
> > Le Sat, 17 Sep 2011 11:32:55 -0400,
> > Nikolaus Rath <Nikolaus-BTH8mxji4b0 public gmane org> a écrit :
> > > > Hi Nikolaus
> > > >
> > > > On Sat, Sep 17, 2011 at 12:56 AM, Nikolaus Rath
> > > > <Nikolaus-BTH8mxji4b0 public gmane org> wrote:
> > > > > Hello,
> > > > >
> > > > > In tracker 0.8.17, an example result of the GetMetadata DBUS
> > > > > method
> > > > is
> > > > >  a nfo:PaginatedTextDocument ;
> > > > >         nie:title "SV Meldung" ;
> > > > >         nco:creator [ a nco:Contact ;
> > > > >         nco:fullname "nikratio"] ;
> > > > >         nie:contentCreated "2011-08-10T20:12:38Z" ;
> > > > >         nao:hasTag [ a nao:Tag ;
> > > > >         nao:prefLabel "()"] ;
> > > > >         dc:format "application/pdf" ;
> > > > >         nie:description "()" ;
> > > > >         nfo:pageCount 1 ;
> > > > >         nie:plainTextContent "blablabla" .
> > > > >
> > > > > With tracker 0.10.21, however, the same document now gives
> > > > >
> > > > >  a nfo:PaginatedTextDocument ;
> > > > >         nie:title "SV Meldung" ;
> > > > >         nco:creator [ a nco:Contact ;
> > > > >         nco:fullname "nikratio"] ;
> > > > >         nie:contentCreated "2011-08-10T20:12:38Z" ;
> > > > >         dc:format "application/pdf" ;
> > > > >         nie:description "()" ;
> > > > >         nao:hasTag ?tag1 ;
> > > > >         nfo:pageCount 1 ;
> > > > >         nie:plainTextContent "blablabla" .
> > > > > } } WHERE { {
> > > > > ?tag1 a nao:Tag ; nao:prefLabel "()" .
> > > > >
> > > > >
> > > > > I don't know enough about the syntax used here, so I won't claim
> > > > > that it's wrong. However, rdflib fails to parse this and thus
> > > > > breaks my application.
> > > > >
> > > > > Can someone tell me if this is a bug in tracker or in rdflib?
> > > >
> > > > Could you share the error message that rdflib gives you?
> > >
> > > Sure, it's at http://code.google.com/p/rdflib/issues/detail?id=190
> >
> > Most likely rdflib doesn't like the fact that the WHERE of the
> > INSERT is not closed?
>
> That would be my guess too. But I'm surprised to find a WHERE in the
> GetMetadata output in the first place. What is it good for, and why
> is it only included for some documents?
>
>
> Thanks,
>
>    -Nikolaus

The where is here to reuse an existing tag.

INSERT { a tag with label "foo" }
INSERT { file has tag ?tag } WHERE { ?tag has label "foo" }

You can think of it as a sort of secondary key...
I guess it's only included for documents which have tags?