В сообщении от Thursday 08 January 2009 21:40:58 Mikkel Kamstrup Erlandsen написал(а): > 2008/12/19 Mikkel Kamstrup Erlandsen <[email protected]> > > > 2008/12/18 Mikkel Kamstrup Erlandsen <[email protected]> > > > >> 2008/12/18 Mikkel Kamstrup Erlandsen <[email protected]> > >> > >>> 2008/12/18 Mikkel Kamstrup Erlandsen <[email protected]> > >>> > >>>> Hi all, > >>>> > >>>> I have started to write up some proper documentation for link-by-id as > >>>> discussed on the hackfest (it will land in > >>>> http://xesam.org/main/XesamOntologyAbout when ready). To this end I > >>>> came upon some stuff that needed updating in the onto. Please see the > >>>> attached patch. > >>>> > >>>> What the proposed patch does: > >>>> > >>>> * Document xesam:id and xesam:related as mandatedd by link-by-id > >>>> > >>>> * Make xesam:contactMedium a child of xesam:id. This has pretty big > >>>> consequences - like postal addresses, email addresses and what not to > >>>> suddenly become ids. Nonetheless I think it is the right choice > >>>> > >>>> * Make xesam:url a child of xesam:id > >>>> > >>>> Comments? > >>> > >>> I have a comment for myself already :-) > >>> > >>> While it might appear neat to have xesam:postalAddress as ids it also > >>> poses some problems. Namely that I also write in the patch that ids > >>> should generally be prefixed with an URI scheme (like http://, file:// > >>> or isbn:// etc). I would rather not have to write my postal address in > >>> an URI > >>> > >>> :-) > >>> > >>> Obviously this needs a bit of thought... > >> > >> And I also forgot the attachment. Great! Here it is... > > > > Here's an updated patch for the ontology. It does not declare postal > > addresses as ids anymore, but it is a bit more invasive... Here's the > > quick overview: > > > > * Make emailAddress, phoneNumber, url, and contactURL children of > > xesam:id > > > > * Add URI scheme requirements to all children of xesam:id. This is > > required to ensure global uniqueness. I just follow the IANA rules here > > really... > > > > * Document xesam:id and xesam:related as mandatedd by link-by-id > > > > And oh! While I have your attention could you also take a peek at the > > "Ids and Object Relations"-section I added to: > > http://xesam.org/main/XesamOntologyAbout, or if you want to see it in the > > context of the whole onto: http://xesam.org/main/XesamOntology (takes > > longer to load) > > Over two weeks without objections. I've pushed this to bzr trunk. I am > currently working on regenerating the ontology wiki-pages. They will > probably be up-to-scratch in a few days. > > When that is done 1.0 is ready.
I should have written this a bit earlier. http://xesam.org/main/Hackfest2008/Ontology mentions link-by-id refinement. It wasn't voted on or discussed widely though, so let's do it now... The idea is to treat content authorship as a special case and refine "dangling" link representation: 1) xesam:creator chilren are allowed to only link to xesam:ContactMedium of xesam:Contact, which is consistent with the way it's usually done in RDF world. 2) Links by ID between documents are resolved directly to URI of the document(s) if it exists, or a dummy Document of appropriate type is created with ID assigned to it and xesam:Source set to xesam:Unavailable. Examples: 1) BookA references ISBN:xxx and there's a BookB with ISBN:xxx ==> user:BookA xesam:links user:BookB 2) BookA references ISBN:xxx and there's no document with ISBN:xxx ==> user:BookA xesam:links user:DummyBookB. user:DummyBookB rdf:type xesam:Document; rdf:type xesam:Unavailable; # or maybe don't specify Source xesam:isbn "xxx". if BookB with ISBN:xxx appears, (2) is replaced with (1) pros: * no need to turn all IDs into URIs * direct links work much faster * better handing of dangling links: - links to available and unavailable objects "look" the same to applications - dummy objects can have an appropriate type like Document or Media and be properly displayed * documents can't be authored by audio files cons: * reason for linking isn't specified when both objects are available. This doesn't seem to matter to users for links by ISBN and such. * if there are 2 documents with the same ISBN(eg PDF and ODF versions), a link by ISBN would target both of them. However, to properly link the second document, the reason for linking(ISBN reference) must still somehow be available * xesam:creator sort of feels like a createdBy relation Ideas? --Evgeny _______________________________________________ Xesam mailing list [email protected] http://lists.freedesktop.org/mailman/listinfo/xesam
