[OASIS Issue Tracker] (OSLCCORE-45) Use of oslc:range, especially for enumerations, is unclear

[OASIS Issues Tracker <workgroup_mailer@lists.oasis-open.org>]

    [ https://issues.oasis-open.org/browse/OSLCCORE-45?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=61768#comment-61768 ] 

James Amsden commented on OSLCCORE-45:
--------------------------------------

Arthur's response was:

I think the general philosophy for OSLC should be to decide what is
needed for interoperability. By this I mean what is the minimum that
an implementation needs to do to be considered compliant. If for some
operation it is important that the object of a property have a given
RDF type, then specify that with oslc:range. All compliant
implementations MUST do what the spec says when they get data that
conforms to the shape. However, they might also do something sensible
when they get other data. The intension was not that an OSLC
implementation would reject a message if it violated a shape, rather
the intension was that it did something specified by an OSLC spec when
it got data that conformed to the spec.

In W3C SHACL, oslc:range is replaced by sh:class. This means that the
object is of that type or of a subclass where we follow
rdfs:subClassOf links.


> Use of oslc:range, especially for enumerations, is unclear
> ----------------------------------------------------------
>
>                 Key: OSLCCORE-45
>                 URL: https://issues.oasis-open.org/browse/OSLCCORE-45
>             Project: OASIS OSLC Lifecycle Integration Core (OSLC Core) TC
>          Issue Type: Improvement
>            Reporter: David Honey
>            Assignee: Nick Crossley
>
> The Core 2.0 spec seems unclear about the intended usage of oslc:range, especially in relation to enumerated attribute types.
> http://open-services.net/bin/view/Main/OSLCCoreSpecAppendixA#oslc_ResourceShape_Resource says:
> "For properties with a resource value-type, Providers MAY also specify the range of possible resource types allowed, each specified by URI. The default range is http://open-services.net/ns/core#Any.";
> Whereas http://www.w3.org/Submission/2014/SUBM-shapes-20140211/ says:
> "oslc:range MUST NOT be used with datatype properties. It MAY be used with object properties. For object properties, oslc:range is used to specify an allowed rdf:type of the object resource. The value of this property MAY be any rdf:type URI or the following individual:
> oslc:Any
>     This value specifies that there is no constraint on the type of the object resource."
> The latter seems to be more definitive, but fails to provide guidance about enumerations. Here is an example. Say there is an attribute representing Colour. It is an enumeration with the following members:
> label="red" uri=<http://example.com/colour/red>
> label="green" uri=<http://example.com/colour/green>
> label="blue" uri=<http://example.com/colour/blue>
> So in the property definition for this Colour attribute, one would say it has an oslc:valueType of oslc:Resource, and it has oslc:allowedValues of <http://example.com/colour/red>, <http://example.com/colour/green>, and <http://example.com/colour/blue>.
> The first description of oslc:range doesn't give guidance as to what URI should be referenced. It implies it's the URI of something that might define the range of values.
> The second description of oslc:range says it should be an rdf:Type URI. Well, what if in the colour example, we say that colours are defined with some RDF type URI. How does an OSLC client determine the labels of each allowed value (expressed as a URI)?
> Whereas if the intent is that a client should be able to do a GET on the oslc:range object resource, then the spec needs to say that.
> The usability of the spec would be greatly improved with an example of how to represent enumerated properties, and exactly what oslc:range object resources are supposed to be.



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