Re: Nested supportedProperty

On 12/16/14 5:38 PM, Holger Knublauch wrote:
> On 12/17/2014 8:16, Markus Lanthaler wrote:
>>
>>> On the more general topic of properties being global or scoped to
>>> classes, I believe the schema.org people followed the concepts explored
>>> by RDF Schema (with variations of global range and domain definitions),
>>> yet I do not believe there are strong reasons for defining property
>>> semantics this way. I believe it would be more helpful to align the
>> This is probably not the right place to discuss this but IMO there 
>> are quite
>> a few reasons to define properties that way. Just think of 
>> schema.org/name.
>> If it would be bound to a specific class, a client would need to 
>> understand
>> dozens of variations of basically the same concept (or infer 
>> something from
>> the URL structure).
>
> schema:name is bound to Thing, and then inherited down into all other 
> classes. Similarly, any other global property can be defined. 
> Alternatively, if only some classes can have a property, then there 
> are these alternatives:
>
> 1) Define a global range/domain, e.g.
>
>     schema:email schema:domainIncludes schema:Organization
>     schema:email schema:domainIncludes schema:Person
>
> 2) Define an abstract superclass and use inheritance
>
>     schema:email rdfs:domain schema:ThingWithEmail
>     schema:Person rdfs:subClassOf schema:ThingWithEmail
>     schema:Organization rdfs:subClassOf schema:ThingWithEmail
>
> Option 2 is what someone would do in an OO language, and it's easier 
> to convert back and forth with OO systems. The syntax that I would 
> propose for a future (shapes) language would be
>
> schema:ThingWithEmail
>     a rdfs:Class ;
>     :property [
>         :predicate schema:email ;
>         :valueType xsd:string ;
>         :label "email address" ;
>         :comment "..." ;
>         :pattern "some regex" ;
>     ] .
>
> schema:Person
>     a rdfs:Class ;
>     rdfs:subClassOf schema:ThingWithEmail .
>
> schema:Organization
>     a rdfs:Class ;
>     rdfs:subClassOf schema:ThingWithEmail .
>
> which keeps all properties locally scoped.
>
>>> schema.org model with traditional object-oriented modeling, where a
>>> property would be attached to a class. This resolves some of the
>>> problems with overlapping domains/ranges. For example what would happen
>>> if a property has two rangeIncludes and two domainIncludes - which
>>> combinations are really valid? If you scope a property declaration to
>>> the context of a class, this issue is solved much clearer.
>> rangeIncludes and domainIncludes are not about validity.. they are 
>> hints as
>> to what a client should likely expect to find in the 
>> subject/object... but
>> I'm sure you know that.
>
> Yeah, but just having "hints" is not really sufficient to build input 
> forms. Why only have hints if you can have the real thing.
>
> Holger

+1

-- 
Regards,

Kingsley Idehen	
Founder & CEO
OpenLink Software
Company Web: http://www.openlinksw.com
Personal Weblog 1: http://kidehen.blogspot.com
Personal Weblog 2: http://www.openlinksw.com/blog/~kidehen
Twitter Profile: https://twitter.com/kidehen
Google+ Profile: https://plus.google.com/+KingsleyIdehen/about
LinkedIn Profile: http://www.linkedin.com/in/kidehen
Personal WebID: http://kingsley.idehen.net/dataspace/person/kidehen#this