On 25/01/2008, Ian Bicking <[EMAIL PROTECTED]> wrote: > Brian Smith wrote: > > Graham Dumpleton wrote: > >> The issue here is that Apache has its own output filtering > >> system where filters can set headers based on the actual > >> content. Because of this, any output filter must always > >> receive the response content regardless of whether the > >> request is a GET or HEAD. If an application handler tries to > >> optimise things and not return the content, then these output > >> filters may generate different headers for a HEAD request > >> than a GET request, thereby violating the requirement that > >> they should actually be the same. > >> > >> Note that response content is still thrown away for a HEAD > >> request, it is just done at the very last moment after all > >> Apache output filters have processed the data. > > > > Right, that is exactly what I am saying. In Apache's documentation, it > > says that every handler should include the response entity for HEAD > > requests, so that output filters can process the output. However, there > > is nothing in PEP 333 that talks about this behavior. > > Unlike Apache there are no output filters in WSGI;
Well, the concept of output filters does exist in WSGI, they are just called something different. ;-) Anyway, the end result is the same, it is just that how they are modeled in the worlds of Apache and WSGI at the interface level is different. Graham > all middleware gets > to adjust the request as well as the response. So middleware that can't > handle a real HEAD request has an opportunity to turn it into a GET > request. I don't see why PEP 333 needs to talk about this, to me it > seems straight forward enough in a WSGI context, and PEP 333 can't cover > every possible bug someone might introduce into their middleware. > > Ian > _______________________________________________ > Web-SIG mailing list > Web-SIG@python.org > Web SIG: http://www.python.org/sigs/web-sig > Unsubscribe: > http://mail.python.org/mailman/options/web-sig/graham.dumpleton%40gmail.com > _______________________________________________ Web-SIG mailing list Web-SIG@python.org Web SIG: http://www.python.org/sigs/web-sig Unsubscribe: http://mail.python.org/mailman/options/web-sig/archive%40mail-archive.com