lisp/org-gnus.el

   1 ;;; org-gnus.el --- Support for links to Gnus groups and messages from within Org-mode
   2
   3 ;; Copyright (C) 2004-2012 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-mode.
  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 (eval-when-compile (require 'gnus-sum))
  36
  37 ;; Declare external functions and variables
  38 (declare-function message-fetch-field "message" (header &optional not-all))
  39 (declare-function message-narrow-to-head-1 "message" nil)
  40 (declare-function nnimap-group-overview-filename "nnimap" (group server))
  41 ;; The following line suppresses a compiler warning stemming from gnus-sum.el
  42 (declare-function gnus-summary-last-subject "gnus-sum" nil)
  43 ;; Customization variables
  44
  45 (when (fboundp 'defvaralias)
  46   (defvaralias 'org-usenet-links-prefer-google 'org-gnus-prefer-web-links))
  47
  48 (defcustom org-gnus-prefer-web-links nil
  49   "If non-nil, `org-store-link' creates web links to Google groups or Gmane.
  50 When nil, Gnus will be used for such links.
  51 Using a prefix arg to the command \\[org-store-link] (`org-store-link')
  52 negates this setting for the duration of the command."
  53   :group 'org-link-store
  54   :type 'boolean)
  55
  56 (defcustom org-gnus-nnimap-query-article-no-from-file nil
  57   "If non-nil, `org-gnus-follow-link' will try to translate
  58 Message-Ids to article numbers by querying the .overview file.
  59 Normally, this translation is done by querying the IMAP server,
  60 which is usually very fast.  Unfortunately, some (maybe badly
  61 configured) IMAP servers don't support this operation quickly.
  62 So if following a link to a Gnus article takes ages, try setting
  63 this variable to `t'."
  64   :group 'org-link-store
  65   :version "24.1"
  66   :type 'boolean)
  67
  68
  69 ;; Install the link type
  70 (org-add-link-type "gnus" 'org-gnus-open)
  71 (add-hook 'org-store-link-functions 'org-gnus-store-link)
  72
  73 ;; Implementation
  74
  75 (defun org-gnus-nnimap-cached-article-number (group server message-id)
  76   "Return cached article number (uid) of message in GROUP on SERVER.
  77 MESSAGE-ID is the message-id header field that identifies the
  78 message.  If the uid is not cached, return nil."
  79   (with-temp-buffer
  80     (let ((nov (nnimap-group-overview-filename group server)))
  81       (when (file-exists-p nov)
  82         (mm-insert-file-contents nov)
  83         (set-buffer-modified-p nil)
  84         (goto-char (point-min))
  85         (catch 'found
  86           (while (search-forward message-id nil t)
  87             (let ((hdr (split-string (thing-at-point 'line) "\t")))
  88               (if (string= (nth 4 hdr) message-id)
  89                   (throw 'found (nth 0 hdr))))))))))
  90
  91 (defun org-gnus-group-link (group)
  92   "Create a link to the Gnus group GROUP.
  93 If GROUP is a newsgroup and `org-gnus-prefer-web-links' is
  94 non-nil, create a link to groups.google.com or gmane.org.
  95 Otherwise create a link to the group inside Gnus.
  96
  97 If `org-store-link' was called with a prefix arg the meaning of
  98 `org-gnus-prefer-web-links' is reversed."
  99   (let ((unprefixed-group (replace-regexp-in-string "^[^:]+:" "" group)))
 100     (if (and (string-match "^nntp" group) ;; Only for nntp groups
 101              (org-xor current-prefix-arg
 102                       org-gnus-prefer-web-links))
 103         (org-make-link (if (string-match "gmane" unprefixed-group)
 104                            "http://news.gmane.org/"
 105                          "http://groups.google.com/group/")
 106                        unprefixed-group)
 107       (org-make-link "gnus:" group))))
 108
 109 (defun org-gnus-article-link (group newsgroups message-id x-no-archive)
 110   "Create a link to a Gnus article.
 111 The article is specified by its MESSAGE-ID.  Additional
 112 parameters are the Gnus GROUP, the NEWSGROUPS the article was
 113 posted to and the X-NO-ARCHIVE header value of that article.
 114
 115 If GROUP is a newsgroup and `org-gnus-prefer-web-links' is
 116 non-nil, create a link to groups.google.com or gmane.org.
 117 Otherwise create a link to the article inside Gnus.
 118
 119 If `org-store-link' was called with a prefix arg the meaning of
 120 `org-gnus-prefer-web-links' is reversed."
 121   (if (and (org-xor current-prefix-arg org-gnus-prefer-web-links)
 122            newsgroups     ;; Make web links only for nntp groups
 123            (not x-no-archive)) ;; and if X-No-Archive isn't set.
 124       (format (if (string-match "gmane\\." newsgroups)
 125                   "http://mid.gmane.org/%s"
 126                 "http://groups.google.com/groups/search?as_umsgid=%s")
 127               (org-fixup-message-id-for-http message-id))
 128     (org-make-link "gnus:" group "#" message-id)))
 129
 130 (defun org-gnus-store-link ()
 131   "Store a link to a Gnus folder or message."
 132   (cond
 133    ((eq major-mode 'gnus-group-mode)
 134     (let* ((group (cond ((fboundp 'gnus-group-group-name) ; depending on Gnus
 135                          (gnus-group-group-name))         ; version
 136                         ((fboundp 'gnus-group-name)
 137                          (gnus-group-name))
 138                         (t "???")))
 139            desc link)
 140       (when group
 141         (org-store-link-props :type "gnus" :group group)
 142         (setq desc (org-gnus-group-link group)
 143               link desc)
 144         (org-add-link-props :link link :description desc)
 145         link)))
 146
 147    ((memq major-mode '(gnus-summary-mode gnus-article-mode))
 148     (let* ((group gnus-newsgroup-name)
 149            (header (with-current-buffer gnus-summary-buffer
 150                      (gnus-summary-article-header)))
 151            (from (mail-header-from header))
 152            (message-id (org-remove-angle-brackets (mail-header-id header)))
 153            (date (org-trim (mail-header-date header)))
 154            (date-ts (and date
 155                          (ignore-errors
 156                            (format-time-string
 157                             (org-time-stamp-format t)
 158                             (date-to-time date)))))
 159            (date-ts-ia (and date
 160                             (ignore-errors
 161                               (format-time-string
 162                                (org-time-stamp-format t t)
 163                                (date-to-time date)))))
 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       ;; Remove text properties of subject string to avoid Emacs bug
 168       ;; #3506
 169       (set-text-properties 0 (length subject) nil subject)
 170
 171       ;; Fetching an article is an expensive operation; newsgroup and
 172       ;; x-no-archive are only needed for web links.
 173       (when (org-xor current-prefix-arg org-gnus-prefer-web-links)
 174         ;; Make sure the original article buffer is up-to-date
 175         (save-window-excursion (gnus-summary-select-article))
 176         (setq to (or to (gnus-fetch-original-field "To"))
 177               newsgroups (gnus-fetch-original-field "Newsgroups")
 178               x-no-archive (gnus-fetch-original-field "x-no-archive")))
 179       (org-store-link-props :type "gnus" :from from :subject subject
 180                             :message-id message-id :group group :to to)
 181       (when date
 182         (org-add-link-props :date date :date-timestamp date-ts
 183                             :date-timestamp-inactive date-ts-ia))
 184       (setq desc (org-email-link-description)
 185             link (org-gnus-article-link
 186                   group newsgroups message-id x-no-archive))
 187       (org-add-link-props :link link :description desc)
 188       link))
 189    ((eq major-mode 'message-mode)
 190     (setq org-store-link-plist nil)  ; reset
 191     (save-excursion
 192       (save-restriction
 193         (message-narrow-to-headers)
 194         (and (not (message-fetch-field "Message-ID"))
 195              (message-generate-headers '(Message-ID)))
 196         (goto-char (point-min))
 197         (re-search-forward "^Message-ID: *.*$" nil t)
 198         (put-text-property (match-beginning 0) (match-end 0) 'message-deletable nil)
 199         (let ((gcc (car (last
 200                          (message-unquote-tokens
 201                           (message-tokenize-header (mail-fetch-field "gcc" nil t) " ,")))))
 202               (id (org-remove-angle-brackets (mail-fetch-field "Message-ID")))
 203               (to (mail-fetch-field "To"))
 204               (from (mail-fetch-field "From"))
 205               (subject (mail-fetch-field "Subject"))
 206               desc link
 207               newsgroup xarchive)       ; those are always nil for gcc
 208           (and (not gcc)
 209                (error "Can not create link: No Gcc header found."))
 210           (org-store-link-props :type "gnus" :from from :subject subject
 211                                 :message-id id :group gcc :to to)
 212           (setq desc (org-email-link-description)
 213                 link (org-gnus-article-link
 214                       gcc newsgroup id xarchive))
 215           (org-add-link-props :link link :description desc)
 216           link))))))
 217
 218 (defun org-gnus-open-nntp (path)
 219   "Follow the nntp: link specified by PATH."
 220   (let* ((spec (split-string path "/"))
 221          (server (split-string (nth 2 spec) "@"))
 222          (group (nth 3 spec))
 223          (article (nth 4 spec)))
 224     (org-gnus-follow-link
 225      (format "nntp+%s:%s" (or (cdr server) (car server)) group)
 226      article)))
 227
 228 (defun org-gnus-open (path)
 229   "Follow the Gnus message or folder link specified by PATH."
 230   (let (group article)
 231     (if (not (string-match "\\`\\([^#]+\\)\\(#\\(.*\\)\\)?" path))
 232         (error "Error in Gnus link"))
 233     (setq group (match-string 1 path)
 234           article (match-string 3 path))
 235     (when group
 236       (setq group (org-substring-no-properties group)))
 237     (when article
 238       (setq article (org-substring-no-properties article)))
 239     (org-gnus-follow-link group article)))
 240
 241 (defun org-gnus-follow-link (&optional group article)
 242   "Follow a Gnus link to GROUP and ARTICLE."
 243   (require 'gnus)
 244   (funcall (cdr (assq 'gnus org-link-frame-setup)))
 245   (if gnus-other-frame-object (select-frame gnus-other-frame-object))
 246   (when group
 247     (setq group (org-substring-no-properties group)))
 248   (when article
 249     (setq article (org-substring-no-properties article)))
 250   (cond ((and group article)
 251          (gnus-activate-group group)
 252          (condition-case nil
 253              (let* ((method (gnus-find-method-for-group group))
 254                     (backend (car method))
 255                     (server (cadr method)))
 256                (cond
 257                 ((eq backend 'nndoc)
 258                  (if (gnus-group-read-group t nil group)
 259                      (gnus-summary-goto-article article nil t)
 260                    (message "Couldn't follow gnus link.  %s"
 261                             "The summary couldn't be opened.")))
 262                 (t
 263                  (let ((articles 1)
 264                        group-opened)
 265                    (when (and (eq backend 'nnimap)
 266                               org-gnus-nnimap-query-article-no-from-file)
 267                      (setq article
 268                            (or (org-gnus-nnimap-cached-article-number
 269                                 (nth 1 (split-string group ":"))
 270                                 server (concat "<" article ">")) article)))
 271                    (while (and (not group-opened)
 272                                ;; stop on integer overflows
 273                                (> articles 0))
 274                      (setq group-opened (gnus-group-read-group
 275                                          articles nil group)
 276                            articles (if (< articles 16)
 277                                         (1+ articles)
 278                                       (* articles 2))))
 279                    (if group-opened
 280                        (gnus-summary-goto-article article nil t)
 281                      (message "Couldn't follow gnus link.  %s"
 282                               "The summary couldn't be opened."))))))
 283            (quit (message "Couldn't follow gnus link.  %s"
 284                           "The linked group is empty."))))
 285         (group (gnus-group-jump-to-group group))))
 286
 287 (defun org-gnus-no-new-news ()
 288   "Like `M-x gnus' but doesn't check for new news."
 289   (if (not (gnus-alive-p)) (gnus)))
 290
 291 (provide 'org-gnus)
 292
 293
 294 ;;; org-gnus.el ends here