[Zope] Help! Disabling caching for external method

[Oliver Bleutgen]

kosh@aesaeion.com wrote:

> On Wed, 16 Jan 2002, Thomas B. Passin wrote:
> 
> 
>>Hmm, I use external methods all the time with Zope (various versions on
>>Windows) and haven't seen that.  It would be more a browser problem, and
>>Netscape is notorious for caching when you don't want it to.
>>
>>It's possible to put instructions into the page not to cache - but I don't
>>remember the details - isn't it a <meta> tag?
>>
> 
> I have to disagree with this about netscape. I have tested it a lot and
> found that netscape reliably caches pages it is allowed to by spec. What
> you need to do is set the If-Modified-Since header in the RESPONSE to the
> date when the page changed and netscape will go ahead and fetch a new
> version of the page. 


One caveat though, which can bite one.

If you use for instance
<META HTTP-EQUIV=Expires CONTENT="-1d">
to make sure that the page is always fetched from the server, Netscape 
(4.x) won't let you print the document.
It instead prints something like "This page has expired, please reload". 
This can be quite confusing for users.

> My problems have been with IE which most of the time
> ignores that even when you click refresh. If you need other ways to tell
> the browser when to force the page to draw again please look at the http
> 1.0 and 1.1 specs. However it is worth it to note that IE has about the
> worst implementation of those specs I have ever seen in any browser in
> history. The bugs it has with content-type and content-disposition are
> staggering.



Content-disposition isn't part of the http-spec, and most of the other 
problems are (sadly!) by design. I once posted a url of a page at MS' 
knowledge base which describes the horror.

cheers,
oliver