Skip to main content
[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] [List Home]
Re: [higgins-dev] entityID not an attribute?

I'd like to hear what others have to say on this topic as I know there are not yet many CPs that expose entityID as an attribute of an entity.

>>> Paul Trevithick <paul@xxxxxxxxxxxxxxxxx> 09/03/08 10:04 PM >>>

Jim,

Sounds like you think there’s good utility in keeping it the way it is. You may well be right. My reason for changing it is that doing so brings Higgins’ CDM closer to RDF. It might not be a good enough reason. In fact, for folks that couldn’t give a hoot about RDF I realize that this is reason at all!

However, for those of us like me who already see CDM from a semantic (if not entirely from a syntactic) POV as being very close to RDF (and who like the power of RDF and the cool RDF tools), it makes CDM even easier to explain relative to RDF. E.g. We can say quickly that “CDM has the semantics of RDF plus a few syntactic transforms, plus Contexts, plus a more powerful identifier (UDIs vs. HTTP-URIs).”. If we keep EntityIDs as attributes (as they are in IdAS today) then we have another difference to explain. Namely, a kind of automatic copying of the entity’s intrinsic identity (its id) into an attribute of the identity. I know that sounded weird, but in RDF the id IS the thing, it isn’t an attribute of the thing. Or said another way, in RDF every id IS a node in the RDF graph whereas attributes (properties) are links from the node to literals or other nodes.].

Stepping back a bit, I just want to reiterate that as we all know, our common goal is to make IdAS a great API for java developers. To do so we’ve developed CDM — a set of abstractions that are at a higher level than RDF triples and more convenient to work with [I doubt there’s much argument about that!]. So if the consensus is that the IdAS API (and thus CDM) is better served by keeping this “auto-entityId-attribute management” transform the way it is in IdAS today, then here’s all we need to do:

  1. I need to re-edit the relevant higgins wiki pages (e.g. http://wiki.eclipse.org/Entity, etc.) [easy]

  2. Folks need to search and replace any code that used higgins:entityId to use cdm:entityId instead. E.g.:


-Paul


On 9/3/08 6:52 PM, "Jim Sermersheim" <jimse@xxxxxxxxxx> wrote:

  

 I had thought we agreed that http://www.eclipse.org/higgins/ontologies/2008/6/higgins#entityID <http://www.eclipse.org/higgins/ontologies/2008/6/higgins#entityID>  was an attribute found on every entity in a context.  In a recent mail from Paul, he says:    
 

         

 > My latest thinking (reflected in higgins.owl 1.1.106 and the wiki at present) is that we should NOT consider entityID to be "just another attribute". It should be considered something different from an attribute. If you want it, call getEntityID() but you won’t find it in the usual set of attributes.      
 
 



           

 I'm wondering what the reason for this is.  I know that if we say it's an attribute, it allows IdAS consumers to search for entities by partial entityID in an easy way (like find me all the entities where the entityID begins with "tom", where if we make it a special thing, we need to have a special kind of filter element just for it.  So I just wanted to make sure the reason to not include it among attributes is worth losing the natural search capability.        

           

 Jim
 
 


Back to the top