Re: IMAP IDLE command

[Tibor Simko <tibor.simko@cern.ch>]

On Mon, 29 Nov 2010, Lars Magne Ingebrigtsen wrote:
> Nope.  Gnus really doesn't have any sort of mechanism for getting
> updates from the servers asynchronously.  But it'd be nice if it did.

On a somewhat-related notification subject, and thinking of Gnus
internal (non-biff) notification techniques, what is the latest
state-of-the-art of gnus-notify.el and other per-article notification
approaches?  E.g. does new nnimap respect nnmail-read-incoming-hook or
nnmail-prepare-save-mail-hook or somesuch where a per-article
notification function could be plugged?

A use case would go like this: instead of helping user to decide whether
to do `g' (as in the case of IMAP IDLE), one would do `g' periodically
anyway (e.g. via daemon), and if certain conditions are met for certain
articles, notification would get displayed for each interesting article.
(Could be all incoming ones, could be an interesting subset only.)

To decide whether an article is interesting enough for notification,
users would customize a variable say `gnus-notification-regexps' to
define conditions in nnmail-split-fancy style like:

   (("From" "John Boss")
    ("From" "Jane Wife")
    ("To" "emergency\\.team@foo\\.com")
    ("Subject" "IMAP IDLE"))

Hooking upon nnmail-read-incoming-hook or other some such appropriate
place, if a condition is satisfied, a `gnus-notification-function' would
be called, e.g. a simple notify-send call to display the sender and the
subject header via a function like:

   (defun gnus-notification-notify-send (from subject)
     "Notify about new email sent by FROM on SUBJECT."
     (start-process "gnus-notify-send" nil "notify-send"
                    "-i" "/usr/share/pixmaps/gnome-emacs.png"
                    (format "New email from %s" from)
                    (format "Subject: %s" subject)))

Would such a notification system be of general interest to have in Gnus?
It would basically only help users to decide whether to open certain
groups or not; though it could also serve for `quick-scanning' of
activity in some shared IMAP groups, in case several people have access
to the same IMAP account, for example.  (Though an external real-time
biffer may be better suited for this.)

WDYT?

Best regards
-- 
Tibor Simko