root/trunk/lisp/gnus/gnus-mlspl.el

;;; gnus-mlspl.el --- a group params-based mail splitting mechanism

;; Copyright (C) 1998, 1999, 2000, 2001, 2002, 2003, 2004,
;;   2005, 2006, 2007, 2008 Free Software Foundation, Inc.

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

;; This file is part of GNU Emacs.

;; GNU Emacs 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 3, or (at your
;; option) any later version.

;; GNU Emacs 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., 51 Franklin Street, Fifth Floor,
;; Boston, MA 02110-1301, 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.
It does this by calling 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 omitted or nil, all
existing groups are considered.

if NO-CROSSPOST is omitted 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\"))
nnml:mail.others:
\((split-spec . catch-all))

Calling (gnus-group-split-fancy nil nil \"mail.others\") returns:

\(| (& (any \"\\\\(bar@femail\\\\.com\\\\|.*@femail\\\\.com\\\\)\"
           \"mail.bar\")
      (any \"\\\\(foo@nowhere\\\\.gov\\\\|foo@localhost\\\\|foo-redist@home\\\\)\"
           - \"bugs-foo\" - \"rambling-foo\" \"mail.foo\"))
   \"mail.others\")"
  (let* ((newsrc (cdr gnus-newsrc-alist))
         split)
    (dolist (info newsrc)
      (let ((group (gnus-info-group info))
            (params (gnus-info-params info)))
        ;; For all GROUPs that match the specified GROUPS
        (when (or (not groups)
                  (and (listp groups)
                       (memq group groups))
                  (and (stringp groups)
                       (string-match groups group)))
          (let ((split-spec (assoc 'split-spec params)) group-clean)
            ;; Remove backend from group name
            (setq group-clean (string-match ":" group))
            (setq group-clean
                  (if group-clean
                      (substring group (1+ group-clean))
                    group))
            (if split-spec
                (when (setq split-spec (cdr split-spec))
                  (if (eq split-spec 'catch-all)
                      ;; Emit catch-all only when requested
                      (when catch-all
                        (setq catch-all group-clean))
                    ;; Append split-spec to the main split
                    (push split-spec split)))
              ;; Let's deduce split-spec from other params
              (let ((to-address (cdr (assoc 'to-address params)))
                    (to-list (cdr (assoc 'to-list params)))
                    (extra-aliases (cdr (assoc 'extra-aliases params)))
                    (split-regexp (cdr (assoc 'split-regexp params)))
                    (split-exclude (cdr (assoc 'split-exclude params))))
                (when (or to-address to-list extra-aliases split-regexp)
                  ;; regexp-quote to-address, to-list and extra-aliases
                  ;; and add them all to split-regexp
                  (setq split-regexp
                        (concat
                         "\\("
                         (mapconcat
                          'identity
                          (append
                           (and to-address (list (regexp-quote to-address)))
                           (and to-list (list (regexp-quote to-list)))
                           (and extra-aliases
                                (if (listp extra-aliases)
                                    (mapcar 'regexp-quote extra-aliases)
                                  (list extra-aliases)))
                           (and split-regexp (list split-regexp)))
                          "\\|")
                         "\\)"))
                  ;; Now create the new SPLIT
                  (push (append
                         (list 'any split-regexp)
                         ;; Generate RESTRICTs for SPLIT-EXCLUDEs.
                         (if (listp split-exclude)
                             (apply #'append
                                    (mapcar (lambda (arg) (list '- arg))
                                            split-exclude))
                           (list '- split-exclude))
                         (list group-clean))
                        split)
                  ;; If it matches the empty string, it is a catch-all
                  (when (string-match split-regexp "")
                    (setq catch-all nil)))))))))
    ;; Add catch-all if not crossposting
    (if (and catch-all no-crosspost)
        (push catch-all split))
    ;; Move it to the tail, while arranging that SPLITs appear in the
    ;; same order as groups.
    (setq split (reverse split))
    ;; Decide whether to accept cross-postings or not.
    (push (if no-crosspost '| '&) split)
    ;; Even if we can cross-post, catch-all should not get
    ;; cross-posts.
    (if (and catch-all (not no-crosspost))
        (setq split (list '| split catch-all)))
    split))

(provide 'gnus-mlspl)

;;; arch-tag: 62b3381f-1e45-4b61-be1a-29fb27703322
;;; gnus-mlspl.el ends here