[Zope-dev] Last-modified and bobobase_modification_time

[Steve Alexander]

Wei He wrote:
> On Tue, 18 Jun 2002, Oliver Bleutgen wrote:
> 
> 
>>>Would please go a little bit deeper giving an example what information 
>>>HEAD requests don't pass to the server, although it's beyond this topic.
>>
>>HEAD requests are required to have no side effects. On the other hand 
>>they are required to return the same response as GET requests without 
>>the BODY.
>>So GET returning another last-modified header than HEAD would be in 
>>violation of the RFC. This gets worse by the fact that HEAD can be used 
>>for caching purposes.
> 
> 
> Totally understood. But the question is what RFC says about the 
> last-modified header. Shouldn't it reflect the latest update? Zope is 
> facing this problem because it handles the HEAD request seperately. 
> Am I right?
> 
> I don't see any need to seperately handle the HEAD request. My hacking of 
> the last-modified header is done execpt that HEAD and wget -S returns 
> different headers. I think the last step is to change the HEAD handling 
> routine to the get information from GET. Does anyone have any idea?

If you *really* want to, you can run a HEAD just like a GET, but after 
getting your last-modified and other details, abort the transaction to 
undo side-effects, then return the HEAD response.

I would generally recommend against this, as it may end up being rather 
expensive.

--
Steve Alexander