[8366] in www-talk@info.cern.ch
Re: Recognizing CGI script responses
daemon@ATHENA.MIT.EDU (Koen Holtman)
Thu Jun 8 13:01:13 1995
Date: Thu, 8 Jun 1995 12:53:53 +0500
Errors-To: procmaster@www19.w3.org
Reply-To: koen@win.tue.nl
From: koen@win.tue.nl (Koen Holtman)
To: Multiple recipients of list <www-talk@www10.w3.org>
[Second try at posting this, first attempt never got past the mailer
at www10.w3.org....]
Henrik Frystyk Nielsen:
>[Koen Holtman:]
>> Thus, the lack of Last-modified is a means of telling that a response
>> came from a script.
>This doesn't necessarily make it a good thing ;-) You can't and shouldn't
>make any assumptions on the origin of documents from missing headers!
I agree that using the lack of a header to conclude something is
sub-optimal.
However, as long as a there are still many dynamic resources around
that do not return Expires headers, looking at the absence of
Last-modified in deciding not to cache is vastly preferable to doing
nothing (see the message by Ari Luotonen I quoted previously).
>There is no reason to forbid caching of CGI scripts
True, and I don't propose to. I'm thinking along the lines of
`strongly suggesting' that not caching (or at least always doing a
conditional GET) should be the default behavior for responses that
lack both Expires and Last-modified headers.
In the future, things will hopefully evolve to a state where basing
behavior on the lack of headers is increasingly less necessary.
However, the more I think about these issues, the more I am becoming
convinced that this evolution is currently being stalled by a deadlock
situation. I'll write some more about this in a few days.
>Henrik Frystyk frystyk@W3.org
Koen.
