Re: [higgins-dev] IdAS: One attribute per type per DS

[Valery Kokhan <vkokhan@xxxxxxxxxxxxxx>]

Jim,

As I can remember our original assumption was that main difference
between attributes and values is that attributes *can* hold metadatas
while values *can not*. Regardless from the fact that I do not see any
way to model metadata on values using .owl I believe that our original
assumption was 100% correct and just leave it at this.

Now about multiple attributes of the same type on any digital subject.

Take into consideration above assumption I personally believe that on
API level we should allow both approach: multiple attributes of the
same type and multiple values in single attribute.

As a use case for multiple attributes of the same type I'd consider
attribute like "relationship" where we need to keep track of when or
by whom each particular relationship was created or modified.

As a use case for multiple values in single attribute I see attribute
like "favoriteDrinks" where we don't care of when each particular
value was modified by still want to know when entire list was changed.


Valery

Friday, April 27, 2007, 5:13:56 AM, you wrote:

>  
>  
> <trying to clean up as many low-hanging issues as I can while the IdAS interfaces are in flux>
>  
>  
>  
> From previous phone calls, higgins-dev traffic and #higgins IRC
> traffic, I believe consensus is that we want to return the data
> model to one where there is only one attribute of a given type on any digital subject.
>  
>  
>  
> There is some remaining work (IIRC) to do in the higgins.owl, but I
> think we can make the change to the IdAS APIs right now.  This
> change consists of removing the metadata Iterator argument from
> IHasAttributes.getAttribute(URI attrID, Iterator metadata).  This
> was here so we could disambiguate between two same-named
> attributes.  It was a bad idea from the IdAS consumer's PoV.
>  
>  
>  
> We currently still have the ability to associate metadata with
> attributes, and we don't yet have the ability to associate it with
> values.  We could address this at the same time. There's a good
> argument to allow metadata on the values, and some have expressed
> interest in removing metadata from attributes.
>  
>  
>  
> I suspect there are reasons to continue to allow metadata at the attribute.
>  
>  
>  
> If we allow metadata at the value, we need to decide whether it
> plays into the value's equality rule (please say no).
>  
>  
>  
> Jim

>