PQM pages should provide caching information (Epiphany gives me last week's queue)

[Matthew Paul Thomas]

On Mondays I'm often flummoxed when I load <http://pqm.launchpad.net/>, and see something in the queue that I sent to PQM on Thursday or Friday. This seems to happen because PQM doesn't send any caching headers <http://www.ircache.net/cgi-bin/cacheability.py?query=http%3A%2F%2Fpqm.launchpad.net%2F>, so Epiphany doesn't load a new copy until I click Reload.

James will likely correct me here, but I think adding a "Cache-Control: max-age=600" header to each request will make browsers load a new copy if their own is more than ten minutes old, without preventing people from answering the question "what was PQM doing when the PQM server went down".

[James Henstridge (jamesh)]

Just to repeat what I said to Matthew on the list, the web UI isn't sending any information that could be used for cache validation, so the page should always be considered stale.

Adding a "Cache-control: max-age=600" header would cause the page to be considered fresh for 10 minutes, so reloading the page would not necessarily do anything in that period.

[Robert Collins (lifeless)]

We could add cache-control max-age yes. The right age is the refresh time for the web ui, which IIRC is 1 minute - and that is under the minimum cache age anyway. So I think its fairly pointless to do this, but I won't object to a patch.