Re: ISSUE-140: Suggestion to close

I also feel that the core of Eric's issue is solved but if we go with this
PR as is, we move from one edge to another.
However, I also agree that targetNode can be an antipattern that we do not
want to promote so much with the spec
(binding shapes with specific nodes in advance)

Maybe we could try a mix of different target schemes as well as some
examples without targets.
But we should somehow differentiate the target-based validation with the
targetless/ShEx validation.

On Mon, Oct 31, 2016 at 2:41 AM, Holger Knublauch <holger@topquadrant.com>
wrote:

>
>
> On 31/10/2016 17:54, Eric Prud'hommeaux wrote:
>
>> * Holger Knublauch <holger@topquadrant.com> [2016-10-31 09:29+1000]
>>
>>> Thanks for your work on the results tables, Eric. I have seen your pull
>>> request but I disagree with deleting the sh:targetXY triples from the
>>> examples. These need to be restored IMHO.
>>>
>> I think this gets to the heart of the issue. In earlier discussions,
>> several of us said that dedicating a schema to a specific dataset is
>> an antipattern. targetNode is particularly problematic in tha respect
>> but even the rest of target* leave open questions. Most of your
>> examples use targetClass which requires a specific type arc. If the
>> data serves multiple purposes (e.g. an ex:SalesContact and an
>> ex:User), you need discriminating type arcs for all the roles it may
>> play.
>>
>
> ISSUE-140 originally was about clarifying that *in addition to graph-based
> validation using targets* SHACL engines should support an interface to
> validate individual nodes by other means. Targets are part of SHACL. By
> leaving them out of the examples you may get closer to your (controversial)
> viewpoint, but it doesn't help to explain SHACL's graph-based mode of
> operation. The boxes are labeled "shapes graph" and "data graph", so it's
> fair to assume that these are meant to be consistently used as explained.
> We have various sections that explain how the targets are used. It's
> valuable to have consistency, and examples of targets have been requested
> multiple times.
>
>
>> Is TopQuadrant's use case addressed by the target* section as it
>> stands in my proposal?
>>
>
> I don't think your branch has made changes to the target sections from the
> main branch? But yes, the current design addresses the use cases that we
> have for SHACL.
>
> Holger
>
>
>
>
>>
>> (See https://github.com/w3c/data-shapes/pull/22/files)
>>>
>>> Holger
>>>
>>>
>>> On 26/10/2016 22:01, Eric Prud'hommeaux wrote:
>>>
>>>> * Holger Knublauch <holger@topquadrant.com> [2016-10-07 10:59+1000]
>>>>
>>>>> We are down to 14 open issues right now, and I am keen on making
>>>>> further
>>>>> progress. My take is the sooner we have the formal list of open issues
>>>>> down,
>>>>> the earlier we can focus on the informal issues raised from the
>>>>> outside.
>>>>>
>>>>> ISSUE-140 was last discussed
>>>>>
>>>>> https://www.w3.org/2016/09/27-shapes-minutes.html#item08
>>>>>
>>>>> but I have to confess I did not quite understand what problem Eric was
>>>>> referring to. It seems that Eric was merely pointing out that
>>>>> validation can
>>>>> be defined independently from specific node selection (i.e. target)
>>>>> mechanisms. I of course agree with that. Could you clarify?
>>>>>
>>>> I've forked the spec and gone through about half of the examples (up
>>>> to sh:and) and added tabular summaries:
>>>>
>>>> https://ericprud.github.io/data-shapes/shacl/
>>>>
>>>> I believe this helps readers and addresses this issue.
>>>>
>>>>
>>>> Ted seemed to request some more detail in the spec about how the
>>>>> validation
>>>>> of individual nodes is supposed to happen. We already have one such
>>>>> interface, the sh:hasShape function, which can be invoked to trigger
>>>>> the
>>>>> validation of a given node against a given shape. We have no such
>>>>> interface
>>>>> for the case in which only a node is given. But we also don't formally
>>>>> define how the validation is triggered in the general, whole-graph
>>>>> case. We
>>>>> could potentially add a function sh:validateNode(?node) that validates
>>>>> the
>>>>> given node against all shapes with matching targets. But then people
>>>>> will
>>>>> likely complain that we are adding yet another SPARQL implementation
>>>>> requirement. Alternatively, Ted, could you clarify how else we can
>>>>> meet your
>>>>> requirement?
>>>>>
>>>>> Thanks,
>>>>> Holger
>>>>>
>>>>>
>>>>>
>>>>>
>>>>> On 23/09/2016 10:11, Holger Knublauch wrote:
>>>>>
>>>>>> I had raised https://www.w3.org/2014/data-shapes/track/issues/140
>>>>>> myself,
>>>>>> primarily as a reminder that validation of individual nodes should be
>>>>>> mentioned in the spec. I have meanwhile added a sentence which IMHO
>>>>>> addresses this need.
>>>>>>
>>>>>> PROPOSAL: Close ISSUE-140 as addressed by
>>>>>> https://github.com/w3c/data-shapes/commit/2046305962be7cd474
>>>>>> 00e7a2b51cd2841dca398c
>>>>>>
>>>>>> Holger
>>>>>>
>>>>>>
>>>
>
>


-- 
Dimitris Kontokostas
Department of Computer Science, University of Leipzig & DBpedia Association
Projects: http://dbpedia.org, http://rdfunit.aksw.org,
http://aligned-project.eu
Homepage: http://aksw.org/DimitrisKontokostas
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