[Nml-wg] References

[Roman Łapacz]

One more thing. Some time ago we discussed the use of id/idRef for 
inheritance. This also could be implemented by the relation. Example:

<nml:Port id="urn:ogf:network:example.net:2012:port-X:out">
<nml:Relation 
type="http://schemas.ogf.org/nml/2012/10/relation/inheritedFrom">
<nml:Port id="urn:ogf:network:example.net:2012:port-X"/>
</nml:Relation>
</nml:Port>

Roman


W dniu 2012-09-21 11:42, Roman Łapacz pisze:
> I decided to visualize the proposed change using an example:
>
> IdRef:
>
> <nml:Port id="urn:ogf:network:example.net:2012:port-X:out">
> <nml:Label 
> encoding="http://schemas.ogf.org/nml/2012/10/ethernet/vlan">1501</nml:Label>
> <nml:Relation 
> type="http://schemas.ogf.org/nml/2012/10/relation/isSource">
> <nml:Link idRef="urn:ogf:network:example.net:2012:linkA:XY"/>
> </nml:Relation>
> </Port>
>
>
> transformed to use isDefinedBy (the way how I see it):
>
> <nml:Port id="urn:ogf:network:example.net:2012:port-X:out">
> <nml:Label 
> encoding="http://schemas.ogf.org/nml/2012/10/ethernet/vlan">1501</nml:Label>
> <nml:Relation 
> type="http://schemas.ogf.org/nml/2012/10/relation/isSource">
> <nml:Link id="urn:ogf:network:example.net:2012:linkA:XY">
> <nml:Relation 
> type="http://schemas.ogf.org/nml/2012/10/relation/isDefinedBy">
> <nml:NetworkObject 
> type="http://schemas.ogf.org/nml/2012/10/type/unknown"/>
> </nml:Relation>
> </nml:Link>
> </nml:Relation>
> </Port>
>
>
> I've introduced a new abstract element nml:NetworkObject that is 
> useful to indicate that the definition is somewhere but does not have 
> to be specified in this xml doc. I don't think we can assume that we 
> must know it in advance. For example, definitions may be located 
> dynamically in some lookup repositories (perfSONAR services does not 
> have to upload their metadata information only to one LS service all 
> the time).  Thus definition location may be found by some lookup 
> mechanism.
>
> I'm fine to use Topology inside Relation if this relation is known:
>
> <nml:Relation 
> type="http://schemas.ogf.org/nml/2012/10/relation/isDefinedBy">
> <nml:Topology id="urn:ogf:network:gn3.net:2012:org"/>
> </nml:Relation>
>
>
>
> The use of Relation for referencing may be useful also for name/id 
> mapping (an id points another id). I'm not sure this may be useful for 
> someone but I can imagine a use case where names of network elements 
> are assigned with a project (see below: pionier network element used 
> in the GN3 project). Such mapping may be helpful for flexible lookup 
> operations.
>
> <nml:Port id="urn:ogf:network:gn3.net:2012:port-X:out">
> <nml:Relation 
> type="http://schemas.ogf.org/nml/2012/10/relation/isDefinedBy">
> <nml:Port id="urn:ogf:network:pionier.net:2012:port-X:out"/>
> </nml:Relation>
> </Port>
>
> <nml:Port id="urn:ogf:network:pionier.net:2012:port-X:out">
> <nml:Label 
> encoding="http://schemas.ogf.org/nml/2012/10/ethernet/vlan">1501</nml:Label>
> <nml:Relation 
> type="http://schemas.ogf.org/nml/2012/10/relation/isSource">
> <nml:Link idRef="urn:ogf:network:pionier.net:2012:linkA:XY"/>
> </nml:Relation>
> </Port>
>
>
> Roman
>
>
> W dniu 2012-09-21 09:50, Jerry Sobieski pisze:
>> If I understand this correctly, and if I also understand the usage 
>> context with regard to "topologies", I vote for the isDefinedBy 
>> construct as we will be looking to acquire what is likely to be a 
>> substantial amount of topology information that is maintained in a 
>> separate document somewhere.
>>
>> And I would salute the desire to keep multiple representations as 
>> similar as possible.
>>
>> (just letting you know I am following these discussions:-)
>> J
>> On 9/20/12 8:44 PM, Freek Dijkstra wrote:
>>> On 20-09-2012 17:13, Jeroen van der Ham wrote:
>>>> Hi,
>>>>
>>>> We've been discussing references, meaning things that are not defined
>>>> locally, but you do want to provide additional information about
>>>> them. For XML there has been a proposal to use id / idRef to denote
>>>> something like that. Unfortunately it is not very easy to port that
>>>> construct to RDF/OWL. The only way to express something like that in
>>>> RDF/OWL is by using a relation. Fortunately a relation like that
>>>> already exists in the form of rdfs:isDefinedBy. This states that an
>>>> object is actually defined by another description, and conveniently
>>>> provides the URL of that description to reference it.
>>>>
>>>> Could we perhaps use the isDefinedBy construct also in XML to make
>>>> the reference definition somewhat more explicit? This would really
>>>> help keeping the difference between the two syntaxes at a minimum
>>>> also.
>>> A summary of the earlier discussion:
>>>
>>> idRef is suppossed to be a shortcut for id + isReference True.
>>>
>>> isReference is supposed to mean that the object was defined elsewhere,
>>> like in another document/by another organisation (there was still a
>>> discussion between Aaron and myself if 'elsewhere' may or may not
>>> included 'elsewhere in the file --- thinking about it now, I would say
>>> 'in another Topology').
>>>
>>> The distinction between isReference and isDefinedBy is that isReference
>>> only tells the parser that it is defined elsewhere; isDefinedBy also
>>> tells the parser where it is defined.
>>>
>>> I have no preference. Based on Jeroen's proposal and the earlier
>>> discussion, what it most useful?
>>>
>>> Freek
>>> _______________________________________________
>>> nml-wg mailing list
>>> nml-wg at ogf.org
>>> https://www.ogf.org/mailman/listinfo/nml-wg
>>
>> _______________________________________________
>> nml-wg mailing list
>> nml-wg at ogf.org
>> https://www.ogf.org/mailman/listinfo/nml-wg
>