Re: Draft 01 of HTTP/1.0
Paul Burchard (burchard@horizon.math.utah.edu)
Sat, 31 Dec 94 18:00:02 -0700
[Roy Fielding responds patiently to:]
> [Paul Burchard's hasty comments on the HTTP draft:]
> > (1) In the definition of the Accept request header, there is no
> > mention of a "version" modifier, e.g.,
> > Accept: text/html; version=3.0
>
> The BNF for Accept (Section 5.5.8) includes *(";" parameter):
Ah, so it does! Still, I think it's worth pointing this out
specially, because gauging client capabilities reliably has been a
real problem in the past.
> > (2) The semantics of Expires should discourage clients from
> > _indiscriminately_ trying to refetch objects, just because
> > they have expired. Dynamically-created pages can be ephemeral,
> > without having time-dependent content that needs to be updated.
>
> I will try to clarify that.
Unfortunately, what needs to be clarified is that my interpretation
of Expires was incorrect. :-)
As Chris Lilley put it, I was taking a server-centric view of
expiration, whereas Expires was always intended to refer to the
client's viewpoint. So, expiration *does* mean that the client is
encouraged to re-fetch the URL. I've updated my own server scripts
accordingly.
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Paul Burchard <burchard@math.utah.edu>
``I'm still learning how to count backwards from infinity...''
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