[Zope] Proxy......

Dieter Maurer dieter@handshake.de
Fri, 23 Nov 2001 18:33:19 +0100


alex writes:
 > you have to set 2 headers:
 > Expires: -1
 > Cache-Control: No-Cache
 > 
 > in zope you set them with
 > RESPONSE.setHeader('Expires','-1')
 > RESPONSE.setHeader('Cache-Control','No-Cache')
The HTTP spec requires "Expires" to have a datetime value in a
specific restricted format (RFC822 with timezone fixed to GMT).
"-1" does not meet this specification.

Thus, setting "Expires" to "-1" may or may not work...

Moreover, "Cache-Control" is defined in "HTTP 1.1" but not in
"HTTP 1.0". Therefore, HTTP 1.1 compliant agents will understand
it, while older agents (implemennting a superset of HTTP 1.0) may
or may not understand it. "Expires" is already defined by HTTP 1.0.


Dieter