Re: Issue with your User Story for the RDF Data Shapes WG

On 02/10/2015 05:51 PM, Arnaud Le Hors wrote:
> Hi Sandro,
> Unfortunately we haven't heard from you in a while and there is an 
> issue that was raised against one of the user stories you contributed. 
> I'd like to know whether you would care to try and address it or if we 
> should do as we see fit - which may include abandoning it.
>

Thanks for bringing this to my attention.  Sorry, I haven't been able to 
be active in the group.   (And I'm starting two weeks travel tomorrow.)

I don't really understand how Issue-13 is phrased.   Are constraints 
important?   Constraints on what?

To briefly rephrase the user story: there is one application (eg Cimba) 
which stores application state in RDF.   It currently queries and 
modifies that state using HTTP GET and PUT operations on RDF Sources, 
but we have another version being developed that uses SPARQL to query 
and modify the  data.   The question is, how do we communicate the shape 
of the data this application reads and writes to other developers who 
want to make compatible applications?   We want to say: as long as your 
data is of this form, Cimba will read it properly.   We also want to 
say: Cimba may write data of any of these forms, so to be interoperable, 
your application will need to read and correctly process all of them.

For example, the query Cimba should use to show the 10 most recent posts 
by people being followed looks something like this:

SELECT ?date ?content ?owner WHERE {
[USER] space:storage ?storage.
?storage ldp:contains ?chanSpace.
?chanSpace a mblog:ChannelSpace.
?chanSpace ldp:contains ?subList.
?subList a mblog:SubscriptionList.
?subList ldp:contains ?subscr
?subscr a mblog:Subscription.
?subscr mblog:toChannel ?chan.
?post a mblog:Post.
?chan ldp:contains ?post.
?post mblog:content ?content;
       dct:created ?date;
       mblog:owner ?owner.

}
ORDER BY ?date
LIMIT 10.

For a diagram of this (possibly a slightly different version), see [1].

Is that how we're supposed to communicate this?   With example 
pseudo-SPARQL queries and diagrams like that?  I would have thought "RDF 
Data Shapes" would help.   It does by my reading of the charter.

To my reading and dim recollection, this is pretty much the same use 
case I heard Google asking for at the workshop, although they were 
imagining HTML web pages with embedded RDF, it's still it's roughly the 
same thing.   I'd imagine IBM wants the same thing for both OSLC and 
ActivityStreams [2], where, again, one needs to tell application 
developers what they're allowed to write, and what they need to be 
prepared to read.

      -- Sandro


[1] 
https://drive.google.com/file/d/0BxONq_ZdKjPVWFhBR2FKakNQMU0/view?usp=sharing
[2] http://www.w3.org/TR/2015/WD-activitystreams-core-20150129/

> See the following:
>
> ISSUE-13 - S12 no constraints
> https://www.w3.org/2014/data-shapes/track/issues/13
>
> Best regards.
> --
> Arnaud  Le Hors - Senior Technical Staff Member, Open Web Standards - 
> IBM Software Group