Re: [Tracker] Tags hierarchy and cascading delete

[Adrien Bustany <madcat mymadcat com>]

On Mon, 15 Feb 2010 23:52:32 +0100, THEVENET Florent
<florent thevenet laposte net> wrote:
> Hello,
>
> Trying to integrate Tracker in getting things gnome (gtg) I got some
> problem.
>
> First gtg features tags hierarchy.
> To solve that I though we could add a property nao:hasChildrenTag to the
> NAO ontology. But that's not enough because when you'll do a query like
> "SELECT ?t WHERE {?t a task:Task; nao:hasTag <your_tag>.}" it will,
> obviously, returns only tasks that have a direct link with the tag,
> while we want to get tasks that are linked with children tags too.
>
> Then, came another problem.
> when you delete a task in gtg all subtasks are deleted. If you want to
> do that in Tracker you have to get all the subtasks of the task, theirs
> subtasks and finally delete all he tasks you've found.
>
> As all softwares that features hierarchy of things will have the same
> problem. I think it would be useful to solve that in Tracker.
> We could add a tracker property in the ontology that says: a property
> links the subject and the object in a way that, if the subject is
> deleted the object must be deleted as well.
> Don't know if it's clear !
>
> Here is an example for cascading delete:
> let's say we work with objects that are task:Task
> we could define the property task:hasSubtask in the ontology file like
> that:
> > task:hasSubtask a rdf:Property ;
> >    rdfs:label "hasSubtask" ;
> >    rdfs:domain task:Task ;
> >    rdfs:range task:Task ;
> >    tracker:deleteChildwithParent true .
>
> Obviously this is only an idea of mine, so it might be completely dumb.
> But this problem is very important, so please solve it, the way you
> want, or tell me how to do if I can do it right now.

Hi Florent
transitivity and graph path are part of the next SPARL draft IÂthink. You
might want to look at how Virtuoso does it, though it's not in Tracker
currently :
http://docs.openlinksw.com/virtuoso/rdfsparql.html#sparqlextensions

Cheers
> Thanks,
> Florent ThÃvenet
>
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