[oslc-core] Core Issue 43 : "read only and friends" - 0:1 oslc:valueShape but 0:* oslc:range

[John Arwe]

Per my action from last week, I've started to draft clarifying changes for 
the subject issue [1].  In comparing the text in Core (defining resources) 
[2] and Core Appendix A (resource shapes) [3] I've run into some new cases 
that we have not discussed in [4] or [5] or IIRC the calls, so the 
original intent is unclear.  I'd like to get some feedback on that, with 
the hope of consensus emerging that I can work into the draft before 
posting it.  To make the threading help as much as possible, I'll be good 
and keep it to one issue per thread.

This thread: Resource shape [3] has a mismatch between oslc:range 0:* and 
oslc:valueShape 0:1 (not 0:*). 

We could turn this into a different action, since it is purely an 
inconsistency within Resource Shapes it does not affect resource 
definitions in specs directly.

I know of at least one implementation (Tivoli's Resource Registry, now in 
open beta) whose creation factory accepts resources of many types.  Their 
constraints for creation vary by type.  They had assumed they would expose 
one shape per type (range value), but 0:1 on valueShape prevents that.

The same implementation accepts resources with multiple rdf:type 
predicates (indeed, they exploit this).  They were "reluctant" to have to 
expose one shape per combination of types, so they used extensions with 
matching rules. 

Not sure what the original intent was here, and whether or not that 
implementation (had the intent been clearer or the 0:1 been 0:*) would 
have fallen within the set of scenarios intended to be addressed by 
resource shapes.



[1] http://open-services.net/bin/view/Main/OslcCoreV2Issues
[2] 
http://open-services.net/bin/view/Main/OslcCoreSpecification?sortcol=table;up=#OSLC_Defined_Resources
[3] 
http://open-services.net/bin/view/Main/OSLCCoreSpecAppendixA?sortcol=table;up=#oslc_ResourceShape_Resource
[4] 
http://open-services.net/pipermail/oslc-core_open-services.net/2012-April/001288.html
[5] 
http://open-services.net/pipermail/oslc-core_open-services.net/2012-May/001314.html

Best Regards, John

Voice US 845-435-9470  BluePages
Tivoli OSLC Lead - Show me the Scenario
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