- From: Phil Archer <phil@philarcher.org>
- Date: 2012年3月01日 09:32:49 +0000
- To: Ruben Verborgh <ruben.verborgh@ugent.be>
- CC: W3C SWIG Mailing-List <semantic-web@w3.org>
- Message-ID: <4F4F4241.4080006@philarcher.org>
On 01/03/2012 08:58, Ruben Verborgh wrote: [..] > The document at [2] does convey the intention that comments is the collection of all comment resources and can indeed nicely generate those triples. > Can it make the relation between the blog post and the comments collection? I think you might have me there, i.e. I fear the answer might be no. You want <http://ugent.be/posts/35/> :ifItHasAnyCommentsTheyHaveAUriLike <http://ugent.be/posts/35/comments> We didn't cover that one. I think you'd probably have to use a SPARQL query to look for comments, perhaps making use of NOT EXISTS > (Also if there are no comments?) > [..] > For us, this mismatch is a problem, as we are describing resources in hypermedia APIs and the relations between those resources in RDF. > Unfortunately, in the REST community, making assertions from URI patterns is also not well-received. Indeed. POWDER is an attempt to square that circle with rigorous semantics. Whether that is sufficient, only time will tell. > > I値l look into POWDER now! If you find it comes close to fulfilling your needs, let me know if I can help. > > Thanks, > > Ruben > >> [2] http://philarcher.org/powder/blogcomments.xml > > > >> On 01/03/2012 07:28, Ruben Verborgh wrote: >>> Dear Semantic Web enthousiasts, >>> >>> Suppose we have a Web application for blogging: >>> - /posts/35 is a blog post >>> - /posts/35/comments are the comments to that post >>> - /posts/35/comments/3 is a specific comment to this post >>> >>> In RDF, it is straightforward to make the relation between the blog post and a specific comment: >>> </posts/35> :hasComment</posts/35/comments/3>. >>> It is also easy to describe the relation between a specific comment and all comments: >>> </posts/35/comments/4> :memberOf</posts/35/comments>. >>> >>> However, how do we indicate the relationship between the blog post and *all* comments that belong to it? >>> I.e., what is the relationship between</posts/35> and</posts/35/comments> ? >>> >>> One could make a new predicate for that of course: >>> </posts/35/> :hasComments</posts/35/comments>. >>> But then, we still have to explain the relation between :hasComments and :hasComment; and we壇 have to do that for every such plural predicate. >>> >>> This seems to be a fundamental problem. >>> Clearly, the resource 田omments on blog post 35? exists, but there doesn稚 seem to be a straightforward way to describe it in RDF. >>> RDF lists will not be sufficient: they could indeed explain the relation between a specific comment and all comments, but not the relation between all comments and the blog post. >>> Also note that the indirect relation 点:x :hasComment _:y. _:y :memberOf _:z? is not sufficient: a blog post can have no comments, but even then it still has an (empty) comments resource. >>> >>> Have you encountered this issue and how do you solve it? >>> >>> Kind regards, >> >> -- >> >> Phil Archer >> http://philarcher.org/ >> +44 (0)7887 767755 >> @philarcher1 > > -- Phil Archer http://philarcher.org/ +44 (0)7887 767755 @philarcher1
Received on Thursday, 1 March 2012 09:33:24 UTC