Re: Uniform access to descriptions

Patrick Stickler wrote:
> 
> > In my example, a request for application/rdf+xml could be 303-
> > redirected.  The target of the redirect can still negotiate further,
> > i.e. dereferencing it may yield RDF or N3 or some other format.  If
> > the original request URI wants, it could also perform the
> > 303-redirect if the client only Accepts text/rdf+n3, or any similar
> > description format.
> 
> You seem to be presuming that no other representation exists for that
> resource. Why would 303 be used in the above case, rather than 415?
> 

I'm talking about a specific use-case where the Accept header *only*
contains applicaton/rdf+xml, in which case the XHTML and HTML variants
which do exist SHOULD NOT be returned -- I'm not presuming they don't
exist.

If an RDF representation does exist, it would be served using a 200
response, not a 303.  I don't think 415 applies here, we are talking
about GET requests with no entity body, not PUT or POST requests with
a media type unknown to the server.

>
> If a GET on the query URI in question normally returns an HTML
> instance, and my agent asks for text/n3 and no N3 is available via
> that URI, why would the server send a 303 response?
>  

It wouldn't, unless the server knows of a related resource which is
N3.  If the server knows of no related resource in that media-type,
then the response is 406.  The 303 only indicates that *maybe* there's
a representation (of some other resource) that interests the client.

-Eric