Note: I was looking at the SHACL ttl file from the W3C web site, which
turns out to be quite incomplete. Corey found this file:
https://raw.githubusercontent.com/TopQuadrant/shacl/master/src/main/resources/etc/shacl.shacl.ttl
which makes much more sense. So some of the problems I ran into may be
resolved by this file. I'll see if I can determine that.
kc
On 7/29/15 12:38 PM, Karen Coyle wrote:
>>
>>> I strongly suggest adding documentation and owl DatatypeProperty
>>> declarations with ranges as xsd datatypes. Also to include
>>> ObjectProperty declarations with rdfs:Resource as range. I dont think
>>> adding just those would contradict with anything, and it would help
>>> using SHACL schema with some existing RDF editors.
>>
>> Even with such patches, tools that are not aware of SHACL could still
>> not be used for data entry of SHACL instance models. They don't
>> understand sh:property etc.
>
> If SHACL is an RDF vocabulary, then tools should only need to understand
> RDF semantics. If SHACL cannot be understood as an RDF vocabulary, then
> I think we have a problem. At this point, it's probably best to take
> this to the W3C group discussion, since this is a concern for that
> group. I'll try to formulate something for that mailing list.
>
> kc
>
>> Tools that do not include full SHACL support
>> may use an extended version of the SHACL Turtle file, as you indicate. A
>> simple way of producing range triples is a SPARQL query:
>>
>> CONSTRUCT {
>> ?predicate rdfs:range ?range .
>> }
>> WHERE {
>> ?shape sh:property ?pc .
>> ?pc sh:predicate ?predicate .
>> ?pc sh:valueClass|sh:datatype ?range .
>> }
>>
>> For the (hopefully short) transition period until other tools have
>> caught up, such things may help, and the WG may even produce such an
>> alternative version as a separate deliverable. But IMHO these
>> definitions do not belong into the official main document which neither
>> relies on OWL nor RDFS. Using rdfs:range has consequences (inferences).
>> And who can predict the fate of OWL from here?
>>
>> Regards,
>> Holger
>>
>>
>>>
>>> br,
>>> Miika
>>>
>>> ----- Original Message -----
>>> From: "kcoyle" <[log in to unmask]>
>>> To: [log in to unmask]
>>> Sent: Tuesday, 28 July, 2015 07:14:33
>>> Subject: Re: [RDF AP] Darwin Core, SHACL, and APs
>>>
>>> Holger, I'm thinking about folks who will use available tools to create
>>> the SHACL definitions for their data. I only have this one experience,
>>> so I'm curious what others find. That said, there aren't a lot of open
>>> source/open access tools for RDF data creation, and I presume that most
>>> are imperfect. But if any standard is going to proliferate, it has to
>>> fit into the tools and workflow that are available to people. Having to
>>> have new tools created will undoubtedly slow down acceptance.
>>>
>>> I hope more people will try out SHACL within their current RDF
>>> environments and report back.
>>>
>>> kc
>>>
>>> On 7/27/15 3:24 PM, Holger Knublauch wrote:
>>>> Hi Karen,
>>>>
>>>> On 7/28/15 3:29 AM, Karen Coyle wrote:
>>>>> Miika, the properties are there, but none have ranges, which I think
>>>>> is unfortunate. I presume that ranges would be appropriate, and a
>>>>> stated range serves in a sense as documentation for the intended use
>>>>> of the property.
>>>> The intended use of the SHACL properties is already encoded in the
>>>> Turtle file, using SHACL itself. Adding rdfs:domains and ranges
>>>> would be
>>>> incorrect and misleading. It would cause undesired side effects such as
>>>> inferencing and suffers from the very problems that SHACL was supposed
>>>> to fix - domains and ranges are open-world concepts. Furthermore, the
>>>> usage of properties is context-specific, i.e. properties can have
>>>> different valueClass depending on the context class.
>>>>
>>>> Having said this, if someone wants to go back to OWL/RDFS, it could be
>>>> possible to create a separate OWL vocabulary for SHACL that uses
>>>> owl:Restrictions instead of sh:PropertyConstraints to cover parts of
>>>> SHACL. This may help bridge the gap to tools that are not (yet?) SHACL
>>>> aware. But since SHACL does not depend on OWL at all, and OWL has
>>>> open-world interpretation, it makes no sense to add such things to the
>>>> main SHACL document.
>>>>>
>>>>> The reason Protege fails to load them is that it converts all RDF to
>>>>> OWL (via the Manchester OWL convert API, I believe), and the algorithm
>>>>> drops them due to lack of information that would indicate what the OWL
>>>>> equivalent is. (Note that the Dublin Core 1.1 ontology suffers the
>>>>> same fate for the same reason.) Although they are valid RDF, the
>>>>> properties are, IMO, under-defined for practical use.
>>>> The Protege developers picked the OWL API as its foundation. The OWL
>>>> API
>>>> is not a good choice to operate on arbitrary RDF. Expecting Protege to
>>>> work with SHACL out of the box is a bit like expecting a UML editor to
>>>> work with XML Schema - both UML and XML Schema ultimately use XML yet
>>>> are very different languages. In addition to the syntactic problems,
>>>> tools like Protege would require additional tabs or widgets to edit
>>>> SHACL property declarations, shapes, run constraint checks etc. Until
>>>> this happens you are better off with either editing SHACL files by hand
>>>> or look at SHACL-specific alternatives.
>>>>
>>>> I hope this makes sense. You may want to raise this topic in the Shapes
>>>> WG if you are still concerned.
>>>>
>>>> Holger
>>>>
>>>>>
>>>>> kc
>>>>>
>>>>> On 7/27/15 12:03 AM, Miika Alonen wrote:
>>>>>> Hi,
>>>>>>
>>>>>> I used SHACL in my example profile. Properties and classes are
>>>>>> defined there at the end of the SHACL schema. Some of the property
>>>>>> declarations might be missing and different from the current draft. I
>>>>>> asked about this from Holger (editor) and he added some of the
>>>>>> missing properties, but also replied that it is not meant to be
>>>>>> traditional RDF(s) vocabulary (and those property declarations are
>>>>>> not really needed) as SHACL has its own way of declaring properties.
>>>>>>
>>>>>> So, i suppose Protege (or any other editor) would need new module to
>>>>>> fully support SHACL once it is finished.
>>>>>>
>>>>>> br,
>>>>>> Miika
>>>>>>
>>>>>> ----- Original Message -----
>>>>>> From: "kcoyle" <[log in to unmask]>
>>>>>> To: [log in to unmask]
>>>>>> Sent: Sunday, 26 July, 2015 23:44:55
>>>>>> Subject: Re: [RDF AP] Darwin Core, SHACL, and APs
>>>>>>
>>>>>> Kai, Thomas,
>>>>>>
>>>>>> is there an RDF vocabulary behind that that can be shared? I'm
>>>>>> curious
>>>>>> how close it adheres to DSP/DCAM.
>>>>>>
>>>>>> Also, has anyone yet played with the SHACL turtle file?[1] It's
>>>>>> probably
>>>>>> just a draft, but I find it to be rather odd, with no ranges on
>>>>>> properties, and classes which are essentially "methods." I'm
>>>>>> curious how
>>>>>> it plays in software people are using. (It fails in Protege[1],
>>>>>> but that
>>>>>> requires a conversion to OWL.)
>>>>>>
>>>>>> kc
>>>>>> [1] http://w3c.github.io/data-shapes/shacl/shacl.shacl.ttl
>>>>>> [2] http://protege.stanford.edu/
>>>>>>
>>>>>> On 7/23/15 4:08 PM, Kai Eckert wrote:
>>>>>>> BTW, Thomas has provided the long-missed implementation of DSP,
>>>>>>> so the
>>>>>>> point of your interviewees is not valid anymore, at least for RDF
>>>>>>> data.
>>
>
--
Karen Coyle
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m: 1-510-435-8234
skype: kcoylenet/+1-510-984-3600
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