lisp/org-gnus.el

   1 ;;; org-gnus.el --- Support for Links to Gnus Groups and Messages -*- lexical-binding: t; -*-
   2
   3 ;; Copyright (C) 2004-2017 Free Software Foundation, Inc.
   4
   5 ;; Author: Carsten Dominik <carsten at orgmode dot org>
   6 ;;         Tassilo Horn <tassilo at member dot fsf dot org>
   7 ;; Keywords: outlines, hypermedia, calendar, wp
   8 ;; Homepage: http://orgmode.org
   9 ;;
  10 ;; This file is part of GNU Emacs.
  11 ;;
  12 ;; GNU Emacs is free software: you can redistribute it and/or modify
  13 ;; it under the terms of the GNU General Public License as published by
  14 ;; the Free Software Foundation, either version 3 of the License, or
  15 ;; (at your option) any later version.
  16
  17 ;; GNU Emacs is distributed in the hope that it will be useful,
  18 ;; but WITHOUT ANY WARRANTY; without even the implied warranty of
  19 ;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  20 ;; GNU General Public License for more details.
  21
  22 ;; You should have received a copy of the GNU General Public License
  23 ;; along with GNU Emacs.  If not, see <http://www.gnu.org/licenses/>.
  24 ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
  25 ;;
  26 ;;; Commentary:
  27
  28 ;; This file implements links to Gnus groups and messages from within Org.
  29 ;; Org mode loads this module by default - if this is not what you want,
  30 ;; configure the variable `org-modules'.
  31
  32 ;;; Code:
  33
  34 (require 'org)
  35 (require 'gnus-util)
  36 (eval-when-compile (require 'gnus-sum))
  37
  38 ;; Declare external functions and variables
  39
  40 (declare-function message-fetch-field "message" (header &optional not-all))
  41 (declare-function message-narrow-to-head-1 "message" nil)
  42 (declare-function gnus-summary-last-subject "gnus-sum" nil)
  43 (declare-function nnvirtual-map-article "nnvirtual" (article))
  44
  45 ;; Customization variables
  46
  47 (defvaralias 'org-usenet-links-prefer-google 'org-gnus-prefer-web-links)
  48
  49 (defcustom org-gnus-prefer-web-links nil
  50   "If non-nil, `org-store-link' creates web links to Google groups or Gmane.
  51 \\<org-mode-map>When nil, Gnus will be used for such links.
  52 Using a prefix argument to the command `\\[org-store-link]' (`org-store-link')
  53 negates this setting for the duration of the command."
  54   :group 'org-link-store
  55   :type 'boolean)
  56
  57 (defcustom org-gnus-nnimap-query-article-no-from-file nil
  58   "If non-nil, `org-gnus-follow-link' will try to translate
  59 Message-Ids to article numbers by querying the .overview file.
  60 Normally, this translation is done by querying the IMAP server,
  61 which is usually very fast.  Unfortunately, some (maybe badly
  62 configured) IMAP servers don't support this operation quickly.
  63 So if following a link to a Gnus article takes ages, try setting
  64 this variable to t."
  65   :group 'org-link-store
  66   :version "24.1"
  67   :type 'boolean)
  68
  69 (defcustom org-gnus-no-server nil
  70   "Should Gnus be started using `gnus-no-server'?"
  71   :group 'org-gnus
  72   :version "24.4"
  73   :package-version '(Org . "8.0")
  74   :type 'boolean)
  75
  76 ;; Install the link type
  77 (org-link-set-parameters "gnus" :follow #'org-gnus-open :store #'org-gnus-store-link)
  78
  79 ;; Implementation
  80
  81 (defun org-gnus-nnimap-cached-article-number (group server message-id)
  82   "Return cached article number (uid) of message in GROUP on SERVER.
  83 MESSAGE-ID is the message-id header field that identifies the
  84 message.  If the uid is not cached, return nil."
  85   (with-temp-buffer
  86     (let ((nov (and (fboundp 'nnimap-group-overview-filename)
  87                     ;; nnimap-group-overview-filename was removed from
  88                     ;; Gnus in September 2010, and therefore should
  89                     ;; only be present in Emacs 23.1.
  90                     (nnimap-group-overview-filename group server))))
  91       (when (and nov (file-exists-p nov))
  92         (mm-insert-file-contents nov)
  93         (set-buffer-modified-p nil)
  94         (goto-char (point-min))
  95         (catch 'found
  96           (while (search-forward message-id nil t)
  97             (let ((hdr (split-string (thing-at-point 'line) "\t")))
  98               (if (string= (nth 4 hdr) message-id)
  99                   (throw 'found (nth 0 hdr))))))))))
 100
 101 (defun org-gnus-group-link (group)
 102   "Create a link to the Gnus group GROUP.
 103 If GROUP is a newsgroup and `org-gnus-prefer-web-links' is
 104 non-nil, create a link to groups.google.com or gmane.org.
 105 Otherwise create a link to the group inside Gnus.
 106
 107 If `org-store-link' was called with a prefix arg the meaning of
 108 `org-gnus-prefer-web-links' is reversed."
 109   (let ((unprefixed-group (replace-regexp-in-string "^[^:]+:" "" group)))
 110     (if (and (string-prefix-p "nntp" group) ;; Only for nntp groups
 111              (org-xor current-prefix-arg
 112                       org-gnus-prefer-web-links))
 113         (concat (if (string-match "gmane" unprefixed-group)
 114                     "http://news.gmane.org/"
 115                   "http://groups.google.com/group/")
 116                 unprefixed-group)
 117       (concat "gnus:" group))))
 118
 119 (defun org-gnus-article-link (group newsgroups message-id x-no-archive)
 120   "Create a link to a Gnus article.
 121 The article is specified by its MESSAGE-ID.  Additional
 122 parameters are the Gnus GROUP, the NEWSGROUPS the article was
 123 posted to and the X-NO-ARCHIVE header value of that article.
 124
 125 If GROUP is a newsgroup and `org-gnus-prefer-web-links' is
 126 non-nil, create a link to groups.google.com or gmane.org.
 127 Otherwise create a link to the article inside Gnus.
 128
 129 If `org-store-link' was called with a prefix arg the meaning of
 130 `org-gnus-prefer-web-links' is reversed."
 131   (if (and (org-xor current-prefix-arg org-gnus-prefer-web-links)
 132            newsgroups     ;; Make web links only for nntp groups
 133            (not x-no-archive)) ;; and if X-No-Archive isn't set.
 134       (format (if (string-match "gmane\\." newsgroups)
 135                   "http://mid.gmane.org/%s"
 136                 "http://groups.google.com/groups/search?as_umsgid=%s")
 137               (org-fixup-message-id-for-http message-id))
 138     (concat "gnus:" group "#" message-id)))
 139
 140 (defun org-gnus-store-link ()
 141   "Store a link to a Gnus folder or message."
 142   (cond
 143    ((eq major-mode 'gnus-group-mode)
 144     (let* ((group (cond ((fboundp 'gnus-group-group-name) ; depending on Gnus
 145                          (gnus-group-group-name))         ; version
 146                         ((fboundp 'gnus-group-name)
 147                          (gnus-group-name))
 148                         (t "???")))
 149            desc link)
 150       (when group
 151         (org-store-link-props :type "gnus" :group group)
 152         (setq desc (org-gnus-group-link group)
 153               link desc)
 154         (org-add-link-props :link link :description desc)
 155         link)))
 156
 157    ((memq major-mode '(gnus-summary-mode gnus-article-mode))
 158     (let* ((group gnus-newsgroup-name)
 159            (header (with-current-buffer gnus-summary-buffer
 160                      (gnus-summary-article-header)))
 161            (from (mail-header-from header))
 162            (message-id (org-unbracket-string "<" ">" (mail-header-id header)))
 163            (date (org-trim (mail-header-date header)))
 164            (subject (copy-sequence (mail-header-subject header)))
 165            (to (cdr (assq 'To (mail-header-extra header))))
 166            newsgroups x-no-archive desc link)
 167       (cl-case  (car (gnus-find-method-for-group gnus-newsgroup-name))
 168         (nnvirtual
 169          (setq group (car (nnvirtual-map-article
 170                            (gnus-summary-article-number)))))
 171         (nnir
 172          (setq group (nnir-article-group (gnus-summary-article-number)))))
 173       ;; Remove text properties of subject string to avoid Emacs bug
 174       ;; #3506
 175       (set-text-properties 0 (length subject) nil subject)
 176
 177       ;; Fetching an article is an expensive operation; newsgroup and
 178       ;; x-no-archive are only needed for web links.
 179       (when (org-xor current-prefix-arg org-gnus-prefer-web-links)
 180         ;; Make sure the original article buffer is up-to-date
 181         (save-window-excursion (gnus-summary-select-article))
 182         (setq to (or to (gnus-fetch-original-field "To"))
 183               newsgroups (gnus-fetch-original-field "Newsgroups")
 184               x-no-archive (gnus-fetch-original-field "x-no-archive")))
 185       (org-store-link-props :type "gnus" :from from :date date :subject subject
 186                             :message-id message-id :group group :to to)
 187       (setq desc (org-email-link-description)
 188             link (org-gnus-article-link
 189                   group newsgroups message-id x-no-archive))
 190       (org-add-link-props :link link :description desc)
 191       link))
 192    ((eq major-mode 'message-mode)
 193     (setq org-store-link-plist nil)  ; reset
 194     (save-excursion
 195       (save-restriction
 196         (message-narrow-to-headers)
 197         (and (not (message-fetch-field "Message-ID"))
 198              (message-generate-headers '(Message-ID)))
 199         (goto-char (point-min))
 200         (re-search-forward "^Message-ID: *.*$" nil t)
 201         (put-text-property (match-beginning 0) (match-end 0) 'message-deletable nil)
 202         (let ((gcc (car (last
 203                          (message-unquote-tokens
 204                           (message-tokenize-header (mail-fetch-field "gcc" nil t) " ,")))))
 205               (id (org-unbracket-string "<" ">" (mail-fetch-field "Message-ID")))
 206               (to (mail-fetch-field "To"))
 207               (from (mail-fetch-field "From"))
 208               (subject (mail-fetch-field "Subject"))
 209               desc link
 210               newsgroup xarchive)       ; those are always nil for gcc
 211           (and (not gcc)
 212                (error "Can not create link: No Gcc header found"))
 213           (org-store-link-props :type "gnus" :from from :subject subject
 214                                 :message-id id :group gcc :to to)
 215           (setq desc (org-email-link-description)
 216                 link (org-gnus-article-link
 217                       gcc newsgroup id xarchive))
 218           (org-add-link-props :link link :description desc)
 219           link))))))
 220
 221 (defun org-gnus-open-nntp (path)
 222   "Follow the nntp: link specified by PATH."
 223   (let* ((spec (split-string path "/"))
 224          (server (split-string (nth 2 spec) "@"))
 225          (group (nth 3 spec))
 226          (article (nth 4 spec)))
 227     (org-gnus-follow-link
 228      (format "nntp+%s:%s" (or (cdr server) (car server)) group)
 229      article)))
 230
 231 (defun org-gnus-open (path)
 232   "Follow the Gnus message or folder link specified by PATH."
 233   (let (group article)
 234     (if (not (string-match "\\`\\([^#]+\\)\\(#\\(.*\\)\\)?" path))
 235         (error "Error in Gnus link"))
 236     (setq group (match-string 1 path)
 237           article (match-string 3 path))
 238     (when group
 239       (setq group (org-no-properties group)))
 240     (when article
 241       (setq article (org-no-properties article)))
 242     (org-gnus-follow-link group article)))
 243
 244 (defun org-gnus-follow-link (&optional group article)
 245   "Follow a Gnus link to GROUP and ARTICLE."
 246   (require 'gnus)
 247   (funcall (cdr (assq 'gnus org-link-frame-setup)))
 248   (if gnus-other-frame-object (select-frame gnus-other-frame-object))
 249   (setq group (org-no-properties group))
 250   (setq article (org-no-properties article))
 251   (cond ((and group article)
 252          (gnus-activate-group group)
 253          (condition-case nil
 254              (let* ((method (gnus-find-method-for-group group))
 255                     (backend (car method))
 256                     (server (cadr method)))
 257                (cond
 258                 ((eq backend 'nndoc)
 259                  (if (gnus-group-read-group t nil group)
 260                      (gnus-summary-goto-article article nil t)
 261                    (message "Couldn't follow gnus link.  %s"
 262                             "The summary couldn't be opened.")))
 263                 (t
 264                  (let ((articles 1)
 265                        group-opened)
 266                    (when (and (eq backend 'nnimap)
 267                               org-gnus-nnimap-query-article-no-from-file)
 268                      (setq article
 269                            (or (org-gnus-nnimap-cached-article-number
 270                                 (nth 1 (split-string group ":"))
 271                                 server (concat "<" article ">")) article)))
 272                    (while (and (not group-opened)
 273                                ;; stop on integer overflows
 274                                (> articles 0))
 275                      (setq group-opened (gnus-group-read-group
 276                                          articles t group)
 277                            articles (if (< articles 16)
 278                                         (1+ articles)
 279                                       (* articles 2))))
 280                    (if group-opened
 281                        (gnus-summary-goto-article article nil t)
 282                      (message "Couldn't follow gnus link.  %s"
 283                               "The summary couldn't be opened."))))))
 284            (quit (message "Couldn't follow gnus link.  %s"
 285                           "The linked group is empty."))))
 286         (group (gnus-group-jump-to-group group))))
 287
 288 (defun org-gnus-no-new-news ()
 289   "Like `\\[gnus]' but doesn't check for new news."
 290   (if (not (gnus-alive-p)) (if org-gnus-no-server (gnus-no-server) (gnus))))
 291
 292 (provide 'org-gnus)
 293
 294
 295 ;;; org-gnus.el ends here