Re: superimposing the Fielding and TBL architectures

Jonathan Rees writes:

> . . .
> In the Fielding architecture the resource is unconstrained. I can give
> you a bunch of different resources, and then when you challenge me to
> prove that there is a resource with those Fielding-representations, I
> can cook up any story I like, post hoc, and you'd have no way to prove
> me wrong.

Presumably you mean "give you a bunch of different _representations_".

I take it this lack of constraint stems from the Fielding-importance
of the role of the URI owner -- it's up to them (without constraint)
to say what a URI identifies, and what is or is not a representation
of whatever that is.  I think I know where the first as-it-were grant
of discretion comes from, but what about the second?  Can you point me
to the relevant bit of 3986?

> In Tim's architecture the resource is determined, modulo usually we
> probably don't care about, by what the correct retrieval results would
> be. Once those results are determined, there's no choice as to what
> the resource is. Contrariwise, if the server side commits to what the
> resource is, we can hold them to it by checking any
> TBL-representations that they deliver.

Sorry to come late to this party, but maybe I'll count as an
intelligent first-time reader of the Final Report.  Does the above
para. amount to saying that the way the owner of a 200-responding URI
establishes what it TBL-identifies is by his/her choice of what is
served with a 200 in response to GET requests for that URI?

So, for example, serving application/rdf+xml or application/n3 as 200
in response to a GET establishes that the URI involved identifies an
RDF graph?

So to sum up

  * wrt the left-hand (TBL) side of your diagram, the owner's free
    will is expressible only via his/her control of the server,

  * whereas on the right-hand (3986) side, the owner's free will is
    expressible _both_ wrt his/her out-of-band statements about what a
    URI identifies _and_ his/her control of the server.

> Nothing much new here, pretty much what Pat has said in different
> words (although I put less stock in "access" and more in social
> agreement over what would constitute correct access were it to occur).

So this is meant to decouple the 'has TBL:representation' link from
the vagaries of connectivity, and/or time variation?  Doesn't that
render it liable to Wittgenstein's counting paradox?  That is, there
is no guarantee that whatever I may induce about a wa:GenericResource
from some retrieval history wrt some URI will stand up to the results
of the next retrieval.

ht
-- 
       Henry S. Thompson, School of Informatics, University of Edinburgh
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Received on Wednesday, 28 September 2011 12:20:14 UTC