[Nepomuk] Re: [Kde-pim] akonadi nepomuk feeder problem, new nepomuk datamanagement service

[Volker Krause]

On Sunday 08 May 2011 20:07:32 Christian Mollekopf wrote:
> Hi,
> 
> While working on a nepomuk note feeder for akonadi, I ran into a problem
> which I'm not sure how to solve.
> 
> The problem is, that the feederagents work with the nepomuk FAST classes.
> Those classes side pass all checks,
> and should therefore be faster. Unfortunately this implies that it is only
> possible to add properties,
> and not to change properties.
> 
> So for notes I need to use
> 
> res.setProperty( Vocabulary::NIE::description(), Soprano::LiteralValue(
> note.text() ) );
> 
> to set the text, so the note gets fulltext indexed. If addProperty is used
> instead,
> we end up with a new description property for every update, meaning all
> versions of the text are available
> and never removed.
> 
> But since I cannot use the FAST classes because they lack the setProperty
> call, and the NepomukFeederAgent base class
> forces me to use the FAST classes we need some other solution.
> 
> The obvious solutions would of course be to not use the FAST classes in
> the first place (which might decrease performance for all feeders).
> 
> But now I was talking to Sebastian Trueg, and he told me of a new
> datamanagement service for Nepomuk living in the nepomuk/datamanagement
> branch of kde-runtime.
> This service adds new convenience functionality, such as automatically
> adding info about the creator of resources, automatic handling of
> dependencies when deleting resource (i.e. if the Thing should be also
> deleted or if it is referenced by another resource). So in the long term I
> think this dms is the way to go (although I don't know if this would
> impose any performance problems, for i.e. the email feeder).
> 
> I'm not sure though when we can start using it.
> The dms will probably be available in kde-runtime for 4.7 and in kdelibs
> 4.8 (according to strueg that is the current plan),
> but afaik kdepim-runtime has no dependency on kde-runtime, so we would
> have to wait for 4.8?
> 
> Soooo, if the dms would go into kdelibs for 4.7 already, could we already
> start using it in kdepim-runtime?

traditionally we depend only on the latest stable release of the KDE platform, 
ie. KDE PIM 4.x has a minimum requirement of kdelibs 4.(x-1). So, a DMS in 4.8 
would mean we can only start using it in KDE PIM 4.9. There might be ways 
around this, like temporary forks of the necessary classes. Quite ugly of 
course, but it allows the use of distro packages for KDE PIM development.

> Solutions for the initial problem, thoughts on the dms?

Sorry, can't really help with that, my contributions to the feeders mainly 
focussed on the Akonadi side so far, I never looked into the details of what 
we actually were doing there on the Nepomuk side ;)

regards
Volker
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