Re: link from ns/shacl to ns/shacl-shacl

On April 10, 2017 12:22:58 AM EDT, Holger Knublauch <holger@topquadrant.com> wrote:
>I do agree that for many data models there will be one very strong 
>"default" shapes graph. However, there was quite some resistance
>against 
>that idea within the WG leading to the point where even sh:targetClass 
>statements were frowned upon by some, because they may tie classes too 
>much to shapes.
>
>In the case of shacl.ttl the shacl-shacl.ttl is one candidate default 
>shapes graph (albeit only for SHACL Core). But I expect that many
>shapes 
>graphs/ontologies will owl:import the shacl.ttl file.
>
>As soon as any file has a transitive owl:imports relation to that file,
>
>it would mean that any locally defined sh:shapesGraph triples would be 
>augmented by that automatic sh:shapesGraph triple. We should be
>prepared 
>for a future in which some people will mix shape, class and data 
>definitions all in the same owl:imports closure. So assuming someone
>has 
>a data graph "mypersons" which owl:imports "personontology" and this
>has 
>a sh:shapesGraph link, then these shapes would apply to all data graphs
>
>that use that ontology. Even worse, there might be a lot of unnecessary
>
>churn with the same shapes being validated over and over again.
>
>While I have no experience with using sh:shapesGraph "in the wild" yet,
>
>I think I would prefer to reserve sh:shapesGraph for the cases in which
>
>a data graph ("instances") points at a shapes graph. The SHACL.ttl file
>
>contains classes, so it does not really fall into that category. So
>yes, 
>I believe there may be cases that need further discussion and it might 
>be more prudent to select another property for this particular case.
>
>How urgent is this decision? I would suggest we put it on the agenda
>for 
>Wednesday.
>

It's not urgent.   This link doesn't have to be normative in SHACL.  

I agree with your argument.   Maybe the link is suggestedShapesGraph, and it's legit to have have multiple ones as alternatives, instead of all applying.

   - Sandro

>Holger
>
>
>On 10/04/2017 13:44, Sandro Hawke wrote:
>> Tim was explicit that rdfs:seeAlso wouldn't be good enough, since he 
>> wants machines to able to do the importing.
>>
>> He may not have thought through all the implications, though. What 
>> kinds of unpredictable things might happen, do you think?  I suppose 
>> it make make some systems validate all their shapes, when that isn't 
>> needed.
>>
>>       -- Sandro
>>
>>
>> On 04/09/2017 10:56 PM, Holger Knublauch wrote:
>>> I think sh:shapesGraph would be an option here:
>>>
>>>     https://www.w3.org/TR/shacl/#sh-shapes-graph
>>>
>>> However, given that the shacl namespace may be imported into a wide 
>>> variety of use cases and thus the potential wide implications of 
>>> adding such a triple are unpredictable right now, what about just 
>>> rdfs:seeAlso?
>>>
>>> Holger
>>>
>>>
>>> On 10/04/2017 12:21, Sandro Hawke wrote:
>>>> TimBL asked us to put a machine readable link from the SHACL 
>>>> namespace document (https://www.w3.org/ns/shacl) to the SHACL 
>>>> document which can be used to validate documents written using that
>
>>>> namespace (https://www.w3.org/ns/shacl-shacl).   This seems like
>the 
>>>> kind of link that would be generally useful, even if only as a
>rough 
>>>> default.  Obviously in many cases, one namespace would be 
>>>> appropriately used in lots of different shapes.  But in some cases 
>>>> (eg SHACL) where there's a sensible default, it'd be nice for the 
>>>> machines to be able to find it.   So, has anyone made such a 
>>>> predicate?    If not, is there a reason not to make it up now, as a
>
>>>> non-rec-track extension?
>>>>
>>>>      -- Sandro
>>>>
>>>>
>>>
>>>
>>
>>

Received on Monday, 10 April 2017 10:39:50 UTC