[sc34wg3] Subject Locators

[Jan Algermissen]

On Jun 13, 2005, at 10:00 PM, Lars Marius Garshol wrote:

>
> * Jan Algermissen
> |
> | When you have a resource that has the intended semantics of some
> | person 'Jim Smith' and
> | NOT some kind of document about him;
> |
> | what is the meaning of
> |
> | <topic id="t1">
> |    <subjectIdentity>
> |      <resourceRef xlink:href="http://example.org/persons/ 
> Jim_Smith"/>
> |    </subjectIdentity>
> | </topic>
> |
> | then?
> |
> | The topic represents Jim Smith - right?
>
> No, it does not. It represents what you get by dereferencing the URI,

Ah. That is a sound statement, compatible with HTTP. I like it.

By definition what you get when dereferencing a URI is a  
representation. So
the topic represents the (one) representation of the resource  
identified by the
URI in the <resourceRef's> href.


> which can't be Jim Smith, but has to be an information resource of
> some kind.

If 'information resource' == representation. Fine. Must be since HTTP/ 
REST
defines that what you get isa represenation.

Agree?

And XTM/TMDM is deliberately ignoring that HTTP content negotiation  
(and time)
might lead to different representations over time, yes? Sometimes I  
will end
up with an HTML document representing Jim Smith another time a JPEG  
image.
(no problem at all, just want to make sure we agree)

Jan



>
> Looking at the wording in TMDM again it seems as though we should
> probably tweak the wording a bit to make it clear that we by "a
> locator that refers to" is not what the URI references, but what you
> get by dereferencing it. (Given that in W3C land what a URI references
> is not necessarily the same as what you get by dereferencing it, this
> may need to be spelled out. The same goes for the wording, which does
> indeed sounds somewhat as though we change the semantics of the URIs.)
>
> So if you wanted a topic representing Jim Smith you'd be better off
> with (in XTM 1.1)
>
> <topic>
>    <subjectIdentity>
>      <subjectIndicatorRef xlink:href="http://example.org/persons/ 
> Jim_Smith"/>
>    </subjectIdentity>
> </topic>
>
> or, if that URI doesn't produce anything related to Jim Smith when
> dereferenced:
>
> <topic>
>    <subjectIdentity>
>      <subjectIndicatorRef xlink:href="http://psi.example.org/ 
> persons/Jim_Smith"/>
>    </subjectIdentity>
> </topic>
>
> -- 
> Lars Marius Garshol, Ontopian         <URL: http://www.ontopia.net >
> GSM: +47 98 21 55 50                  <URL: http:// 
> www.garshol.priv.no >
>
> _______________________________________________
> sc34wg3 mailing list
> sc34wg3@isotopicmaps.org
> http://www.isotopicmaps.org/mailman/listinfo/sc34wg3
>

________________________________________________________________________ 
____________________
Jan Algermissen, Consultant & Programmer                              
http://jalgermissen.com
Tugboat Consulting, 'Applying Web technology to enterprise IT'        
http://www.tugboat.de