Re: Schema.org related SHACL shapes

Hello Holger,

Thank you for the clarification.

This does prompt another question.

Consider, for example, the https://schema.org/latitude property.

When it is a Number, the value of a latitude, when expressed in degrees,
should be between -90 to 90. Currently the SHACL Shape validating
the latitude property would accept any valid instead of producing a
validation error when the values is outside of the valid range. There are
likely other (and better) similar examples which
http://datashapes.org/schema will not produce expected validation errors
for.

Given how the shape is created, this is understandable. It would require
that valid ranges be specified and that is beyond the scope of what a
schema is or should be. An exception to this might be properties like
https://schema.org/byDay which, when it is a https://schema.org/DayOfWeek,
may produce a validation error if an enumeration member is not provided.

While http://datashapes.org/schema provides a basis for a solution to
validate schema.org data instances, it is missing information to produce
validation errors when they would be expected.

Am I off base here?

Regards,
James

On Wed, May 20, 2020 at 9:57 PM Holger Knublauch <holger@topquadrant.com>
wrote:

>
> On 21/05/2020 03:20, James Hudson wrote:
>
> Hello,
>
> Dan B.,
>
> While I am disappointed that no one has already done my work for me :-),
> what you have confirmed (I think) is that it is work worth doing and there
> are no known red flags against considering developing SHACL Shapes which
> would validate schema.org data instances.
>
> If anyone can point me to specific work that have experimented with
> creating SHACL Shapes which validate schema.org data instances, I would
> be interested. I will keep looking.
>
> Based on the breadth and extent of schema.org, it would seem to be a lot
> of work for complete validation.
>
>
> Alasdair,
>
> I looked at your site, but did not see any SHACL Shapes related to
> schema.org classes or properties. I assume you are using them underneath
> somewhere...? Can they be shared?
>
>
> Gregory, Thomas,
>
> Thank you for pointing me at http://datashapes.org/schema. Unless I am
> mistaken, it ( http://datashapes.org/schema.ttl ) seems that is about
> validating schema.org classes and properties itself and not data
> instances.
>
> No, that SHACL file is actually for instances. It is generated from the
> original RDFa definition of the schema.org classes and properties and
> interprets the specified ranges as sh:datatype and sh:class constraints. So
> you *can* use it as a shapes graph when validating instances.
>
> And yes, it's not entirely up to date - if anyone needs the very latest
> version I could re-run the generator (which is also bundled with TBC in
> case anyone has that).
>
> Holger
>
>
>
> Although, their "example file" (
> http://datashapes.org/schemashacl.shapes.ttl ) is what I am looking for,
> but it only covers one class. Still, there will be things in there that I
> can use.
>
> It does provide some nice examples for how to do certain things in SHACL.
>
>
> Umut, Elias,
>
> Thank you for pointing me at semantify.it. I will have to take a closer
> look, but it does not appear to have what I am looking for this time, which
> is literally a SHACL Shape which can validate
> https://schema.org/Invoice#Invoice-gen-367 , for example -- and beyond
> that, SHACL Shapes which could validate data instances of all of the
> schema.org classes and properties. Incomplete solutions would be of value.
>
>
> Regards,
> James
>
>
>
>