[gnus] / lisp / gnus-mlspl.el

;;; gnus-mlspl.el --- a group params-based mail splitting mechanism
;; Copyright (C) 1998, 1999, 2000
;;        Free Software Foundation, Inc.

;; Author: Alexandre Oliva <oliva@lsd.ic.unicamp.br>
;; Keywords: news, mail

;; This program is free software; you can redistribute it and/or modify
;; it under the terms of the GNU General Public License as published by
;; the Free Software Foundation; either version 2, or (at your option)
;; any later version.

;; This program is distributed in the hope that it will be useful,
;; but WITHOUT ANY WARRANTY; without even the implied warranty of
;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
;; GNU General Public License for more details.

;; You should have received a copy of the GNU General Public License
;; along with this program; see the file COPYING.  If not, write to
;; the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
;; Boston, MA 02111-1307, USA.

;;; Commentary:

;;; Code:

(eval-when-compile (require 'cl))
(require 'gnus)
(require 'gnus-sum)
(require 'gnus-group)
(require 'nnmail)

(defvar gnus-group-split-updated-hook nil
  "Hook called just after nnmail-split-fancy is updated by
gnus-group-split-update.")

(defvar gnus-group-split-default-catch-all-group "mail.misc"
  "Group name (or arbitrary fancy split) with default splitting rules.
Used by gnus-group-split and gnus-group-split-update as a fallback
split, in case none of the group-based splits matches.")

;;;###autoload
(defun gnus-group-split-setup (&optional auto-update catch-all)
  "Set up the split for nnmail-split-fancy.
Sets things up so that nnmail-split-fancy is used for mail
splitting, and defines the variable nnmail-split-fancy according with
group parameters.

If AUTO-UPDATE is non-nil (prefix argument accepted, if called
interactively), it makes sure nnmail-split-fancy is re-computed before
getting new mail, by adding gnus-group-split-update to
nnmail-pre-get-new-mail-hook.

A non-nil CATCH-ALL replaces the current value of
gnus-group-split-default-catch-all-group.  This variable is only used
by gnus-group-split-update, and only when its CATCH-ALL argument is
nil.  This argument may contain any fancy split, that will be added as
the last split in a `|' split produced by gnus-group-split-fancy,
unless overridden by any group marked as a catch-all group.  Typical
uses are as simple as the name of a default mail group, but more
elaborate fancy splits may also be useful to split mail that doesn't
match any of the group-specified splitting rules.  See
gnus-group-split-fancy for details."
  (interactive "P")
  (setq nnmail-split-methods 'nnmail-split-fancy)
  (when catch-all
    (setq gnus-group-split-default-catch-all-group catch-all))
  (gnus-group-split-update)
  (when auto-update
    (add-hook 'nnmail-pre-get-new-mail-hook 'gnus-group-split-update)))

;;;###autoload
(defun gnus-group-split-update (&optional catch-all)
  "Computes nnmail-split-fancy from group params and CATCH-ALL, by
calling (gnus-group-split-fancy nil nil CATCH-ALL).

If CATCH-ALL is nil, gnus-group-split-default-catch-all-group is used
instead.  This variable is set by gnus-group-split-setup."
  (interactive)
  (setq nnmail-split-fancy
        (gnus-group-split-fancy
         nil (null nnmail-crosspost)
         (or catch-all gnus-group-split-default-catch-all-group)))
  (run-hooks 'gnus-group-split-updated-hook))

;;;###autoload
(defun gnus-group-split ()
  "Uses information from group parameters in order to split mail.
See gnus-group-split-fancy for more information.

gnus-group-split is a valid value for nnmail-split-methods."
  (let (nnmail-split-fancy)
    (gnus-group-split-update)
    (nnmail-split-fancy)))

;;;###autoload
(defun gnus-group-split-fancy
  (&optional groups no-crosspost catch-all)
  "Uses information from group parameters in order to split mail.  It
can be embedded into nnmail-split-fancy lists with the SPLIT

\(: gnus-group-split-fancy GROUPS NO-CROSSPOST CATCH-ALL\)

GROUPS may be a regular expression or a list of group names, that will
be used to select candidate groups.  If it is ommited or nil, all
existing groups are considered.

if NO-CROSSPOST is ommitted or nil, a & split will be returned,
otherwise, a | split, that does not allow crossposting, will be
returned.

For each selected group, a SPLIT is composed like this: if SPLIT-SPEC
is specified, this split is returned as-is (unless it is nil: in this
case, the group is ignored).  Otherwise, if TO-ADDRESS, TO-LIST and/or
EXTRA-ALIASES are specified, a regexp that matches any of them is
constructed (extra-aliases may be a list).  Additionally, if
SPLIT-REGEXP is specified, the regexp will be extended so that it
matches this regexp too, and if SPLIT-EXCLUDE is specified, RESTRICT
clauses will be generated.

If CATCH-ALL is nil, no catch-all handling is performed, regardless of
catch-all marks in group parameters.  Otherwise, if there is no
selected group whose SPLIT-REGEXP matches the empty string, nor is
there a selected group whose SPLIT-SPEC is 'catch-all, this fancy
split (say, a group name) will be appended to the returned SPLIT list,
as the last element of a '| SPLIT.

For example, given the following group parameters:

nnml:mail.bar:
\((to-address . \"bar@femail.com\")
 (split-regexp . \".*@femail\\\\.com\"))
nnml:mail.foo:
\((to-list . \"foo@nowhere.gov\")
 (extra-aliases \"foo@localhost\" \"foo-redist@home\")
 (split-exclude \"bugs-foo\" \"rambling-foo\")
 (admin-address . \"foo-request@nowhere.gov\"))