Current Agora Status

www-talk@www10.w3.org
Thu, 1 Jun 95 19:01:42 PDT

Kee Hinckley writes:
...
However, even
> that won't work with some caching servers, so you need to go one more step.
> When the "takeorder" script redirects back to the order form, have it pass
> a unique argument everytime (e.g.
> http://www.somewhere.com/order.html?Defeat-Cache=3Dxxx, where xxx is the
> result of "time(0)" or something). The html file will ignore the argument,
> but the presence of the argument will defeat any caching mechanism.
>

There are problems with this approach. If you have a page A that
contains a link in the form you suggest to document B, and you have already
viewed page A and followed the link to B, if you "back up" to A with
browser navigation commands, and then follow B again, you may still
get the *old* document B (because the browser might cache B). This is
precisely where where browsers should respect "expires:", and where
some current ones do not. Moreover, if browsers did respect the
expires header, the "cache-buster" in the URL would not be needed.

--Shel