[Nepomuk] Re: nepomuk & gnome & firefox
Bruce Adams
tortoise_74 at yahoo.co.uk
Tue Nov 23 22:46:09 CET 2010
Hi,
Could someone explain or point me to a summary of what happened there.
I can see there was discussion on various lists around may 2009 but I
haven't so far found any reference to the fork, what forked and why.
Are there any core elements are still common and that we might
expect to remain so?
The ontology structure is very feature rich but how many of the items defined
are
actually used on practical projects?
How much of the ontology is actually used by KDE for example?
I can see that gwen view allows the following:
tags
a description
a rating up to five stars.
Then you have the text search functionality provided by strigi in KDE
and tracker in gnome.
What else is used?
(does anyone maintain an inventory of this sort?)
Is any of the ontology currently unused by anyone at all? Coold some of it be
YAGNI
(you aint' gonna need it)?
It seems to me that the original semantic desktop project aimed to cover a wider
scope
than any system currently uses. To move forward it would be nice to look for
cases that
provide immediate (or at least near term) practical benefit.
Regards,
Bruce.
----- Original Message ----
> From: Evgeny Egorochkin <phreedom.stdin at gmail.com>
> To: nepomuk at kde.org
> Cc: Adrien Bustany <madcat at mymadcat.com>; Bruce Adams
<tortoise_74 at yahoo.co.uk>
> Sent: Tue, November 23, 2010 3:15:40 PM
> Subject: Re: [Nepomuk] Re: nepomuk & gnome & firefox
>
> On Saturday 20 November 2010 21:09:13 Adrien Bustany wrote:
> > Hi all,
> >
> > on GNOME the standard semantic engine is called Tracker
> > (tracker-project.org). It also uses the Nepomuk ontologies, so it
> > should be easy to make things work the same in GNOME and KDE. Having a
> > common interface surely sounds like a good idea. The question is now if
> > we want a high level interface (ie. "add a tag") or a low level one
> > ("run sparql query")...
>
> Unfortunately the "run sparql query" interface is mostly useless if desktops
> are running incompatible ontologies which is the case right now.
>
> > Le Sat, 20 Nov 2010 02:06:51 +0000 (GMT),
> >
> > Bruce Adams <tortoise_74 at yahoo.co.uk> a écrit :
> > > Hi,
> > >
> > > If I may ask what is the other project? As it will obvious have
> > >
> > > bearings on where
> > > you want to focus your efforts.
> > >
> > > Brainstorming sounds like a good plan. Perhaps starting with a wide
> > > scope before narrowing down to what is in and out of scope
> > > and ultimately keeping it simple and acheivable.
> > >
> > > I'm new so apologies that this probably isn't.
> > >
> > > I'd like to start with resource discovery.
> > > Given a URI we need to know.
> > >
> > > what services provide meta data for it
> > > what kind of meta data each service provides (reference to an
> > >
> > > ontology?)
> > >
> > > Given a mounted disk semantic information could be provided by one or
> > >
> > > more of at least the following:
> > > a (e.g. nepomuk) server using a user specific database
> > > a local server using a shared database
> > > a remove server using a shared database
> > > a filesystem that permits embedded semantic information.
> > >
> > > Ideally I'd like to be able to do the same for a web-page which is
> > > why I said URI
> > > rather than file. Including web-pages would most likely imply using
> > > W3 standard methods for passing semantic information around.
> > >
> > > I'm not clear if or how nepomuk handles security issues relating to
> > > users sharing
> > > a database and controlling access and visibility of it.
> > >
> > > For each resource we need to know what priviledges we have.
> > > Most importantly is it read only.
> > >
> > > I'm primarily interested in tagging folksonomies.
> > > I'm sufficiently new that I don't know how (in)compatible the
> > > ontologies used by nepomuk are with those used elsewhere (OSCAF and
> > > Gnome).
> > >
> > > The paper http://tagont.googlecode.com/files/TagOntPaper.pdf
> > > suggests a common ontology.
> > > It includes the following suggested queries which look a lot like
> > > some of my tagging use cases.
> > >
> > > • get all taggers
> > > • get all tags used by a tagger X
> > > • get all resources which have been tagged more
> > > than once
> > > • get all tags for a resource A
> > > • get tags from users X,Y,Z for resource A
> > >
> > >
> > > Myself I would very much like an API that just provides this without
> > > having to writes SPARQL
> > > queries as that lowers the entry requirements for using it.
> > >
> > > Some more vague ramblings in the direction of a (C++) API before I
> > > head off to sleep.
> > > I had something like this in mind for a libtagger.so which it what
> > > started me searching for information
> > > and led me to nepomuk.
> > >
> > > Entity -> File or URL
> > > Service - description of a meta data provider
> > > Tag - includes a simple string name
> > >
> > > std::set<Service> Entity::listServiceProviders()
> > >
> > > std::set< Tag> Entity::listTags()
> > > std::set< Tag> Entity::listTags(<semantic info provider or list
> > >
> > > there>) std::set< Tag> Entity::listTags(<some kind of filter>)
> > >
> > > <some kind of status, or just exceptions when it goes wrong>
> > >
> > > Entity::addTag(tag)
> > >
> > > methods to convert a tag to and from a string simply
> > >
> > > Tag::Tag(std::string) -
> > > std::string Tag::toString()
> > >
> > > perhaps this is only sensible in the context of a given service
> > > provider?
> > >
> > > Service::listDefinedTags();
> > >
> > > Entity::addTag(service, tag, bool createTag)
> > >
> > > I have to say some of this bears a resemblance to the existing
> > > nepomuk API but simplified with not an ontology in sight (though its
> > > there under the hood).
> > >
> > > Meta-data aware file ops.
> > >
> > > CopyFile - copy file & meta-data
> > > MoveFile - move file & meta-data
> > >
> > > The following would apply to URLs as well:
> > > CopyMetaData( file1, file2) - overwrite the meta data for file2
> > >
> > > with that for file1
> > >
> > > CopyMetaData( file, provider1, provider2) - copy the meta data one
> > >
> > > provide has for a file to another provider
> > >
> > > ExportMetaData(file); - to file or a (opaque?) meta data object
> > > ImportMetaData(file);
> > >
> > > These would need to be clever enough to decide what to do based on
> > > the resource providers for the start and end points.
> > >
> > > I was thinking about cobbling this kind of API together for my next
> > > project.
> > >
> > > I also wonder about having a backup file-system based metadata
> > > database along the lines of
> > >
> > > <dir>
> > >
> > > <file to tag>
> > > ,metadata/
> > >
> > > tags/
> > >
> > > <file to tag> <- contains tags as RDF, XML or a list of
> > >
> > > strings one per line.
> > >
> > > Regards,
> > >
> > > Bruce.
> > >
> > >
> > > ----- Original Message ----
> > >
> > > > From: Sebastian Trüg <trueg at kde.org>
> > > > To: Bruce Adams <tortoise_74 at yahoo.co.uk>
> > > > Cc: nepomuk at kde.org
> > > > Sent: Wed, November 17, 2010 2:18:30 PM
> > > > Subject: Re: [Nepomuk] Re: nepomuk & gnome & firefox
> > > >
> > > > Actually I have planned to start on that API mid of next week since
> > > > I need it for another project. Maybe a good idea to start would be
> > > > to brainstorm on the necessary method the API would require, ie.
> > > > come up with a bunch of use cases.
> > > >
> > > > We could put that on techbase.kde.org...
> > > >
> > > > Cheers,
> > > > Sebastian
> > > >
> > > > On 11/17/2010 02:24 PM, Bruce Adams wrote:
> > > > > That's pretty much exactly what I'm looking for.
> > > > > So I'm happy to collaborate on any efforts to get something like
> > > > > that
> > >
> > > going.
> > >
> > > > > Regards,
> > > > >
> > > > > Bruce.
> > > > >
> > > > >
> > > > > ----- Original Message ----
> > > > >
> > > > >> From: Sebastian Trüg <trueg at kde.org>
> > > > >> To: nepomuk at kde.org
> > > > >> Sent: Wed, November 17, 2010 1:04:19 PM
> > > > >> Subject: [Nepomuk] Re: nepomuk & gnome & firefox
> > > > >>
> > > > >> This is what I mean: a DBUs API that provides what the
> > > > >> Nepomuk-KDE API provides at the moment.
> > > > >>
> > > > >> Cheers,
> > > > >>
> > > > >> Sebastian
> > > > >>
> > > > >> On 11/17/2010 09:58 AM, Bruce Adams wrote:
> > > > >>> ----- Original Message ----
> > > > >>>
> > > > >>>> From: Richard Dale <richard.j.dale at gmail.com>
> > > > >>>>
> > > > >>>> To: nepomuk at kde.org
> > > > >>>>
> > > > >>>> Sent: Tue, November 16, 2010 5:40:17 PM
> > > > >>>> Subject: [Nepomuk] Re: nepomuk & gnome & firefox
> > > > >>>>
> > > > >>>> On Wed, Nov 10, 2010 at 7:11 AM, Sebastian Trüg
> > > > >>>> <trueg at kde.org>
> > >
> > > wrote:
> > > > >>>>> The solution is simply what I said: we support the tracker
> > > > >>>>>
> > > > >>>>> API and that's it. The other way around is not possible
> > > > >>>>> anyway.
> > > > >>>>
> > > > >>>> OK, how would you like to support the tracker API? I'm
> > > > >>>> still not
> > >
> > > clear
> > >
> > > > >>>> on what you are saying.
> > > > >>>>
> > > > >>>> One way would be to write a Tracker backend for Soprano 2.x
> > > > >>>> which would support a subset of the Virtuoso backend's
> > > > >>>> functionality.
> > > > >>>>
> > > > >>>> Another way would be to write a QSparql based backend for
> > > > >>>> Soprano 2.x which would interface with Tracker, and also
> > > > >>>> support SPARQL endpoints and Virtuoso as a side effect,
> > > > >>>> although you would be perfectly
> > >
> > > welcome
> > >
> > > > >>>> not to use that extra functionality as the drivers are only
> > > > >>>> plugins. I happen to be an expert on the Tracker apis (both
> > > > >>>> the DBus one and the newer 'direct api'), and the Tracker
> > > > >>>> team are cooperating to improve their api WRT its use in
> > > > >>>> QSparql. I am also an active KDE developer who has
> > > > >>>> developed language bindings for Soprano and Nepomuk, and I
> > > > >>>> am quite happy to work on KDE things in my spare time. So if
> > > > >>>> anyone can do this particular task I feel I should be about
> > > > >>>> the person person to try.
> > > > >>>>
> > > > >>>> I don't know what your plans for Soprano 3.x are as I
> > > > >>>> haven't studied the code yet.
> > > > >>>>
> > > > >>>> -- Richard
> > > > >>>
> > > > >>> From my angle as a noob a lot of this is missing the point.
> > > > >>> I want to read and write tag clouds in a platform independent
> > > > >>> way. A rich ontology is all very well (and vitally important
> > > > >>> for more advanced
> > > > >>
> > > > >> uses).
> > > > >>
> > > > >>> But at the start of the day I want to be able to do something
> > > > >>>
> > > > >>> like:
> > > > >>> Nepomuk::File file( "some/path");
> > > > >>> file.addTag("foo");
> > > > >>>
> > > > >>> Just like in the examples here:
> > > > >>> http://api.kde.org/4.x-api/kdelibs-apidocs/nepomuk/html/examples.
> > > > >>> html
> > > > >>>
> > > > >>> and see the tag "foo" appear in the "quickview" in dolphin and
> > > > >>> the equivalent Gnome apps (and firefox).
> > > > >>>
> > > > >>> Surprisingly this is 'bleeding edge' stuff (kde 4.6) rather
> > > > >>> than the bare
> > > > >>>
> > > > >>> essentials
> > > > >>> and doesn't work on my up to date ubuntu 10.10 installation
> > > > >>>
> > > > >>> which is
> > > >
> > > >still
> > > >
> > > > >> on
> > > > >>
> > > > >>> kde 4.5.1.
> > > > >>> (actually this is beyond the bleeding edge as the tag needs
> > > > >>> to be
> > > >
> > > >declared
> > > >
> > > > >>> first, but you get the idea)
> > > > >>>
> > > > >>> Regards,
> > > > >>>
> > > > >>> Bruce.
>
> Evgeny
>
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