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537ab246 BG |
1 | ;;; rmailmm.el --- MIME decoding and display stuff for RMAIL |
2 | ||
3 | ;; Copyright (C) 2006, 2007, 2008, 2009 Free Software Foundation, Inc. | |
4 | ||
6ea97e7e GM |
5 | ;; Author: Alexander Pohoyda |
6 | ;; Alex Schroeder | |
537ab246 BG |
7 | ;; Maintainer: FSF |
8 | ;; Keywords: mail | |
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 | ;;; Commentary: | |
26 | ||
27 | ;; Essentially based on the design of Alexander Pohoyda's MIME | |
73422054 GM |
28 | ;; extensions (mime-display.el and mime.el). |
29 | ;; Call `M-x rmail-mime' when viewing an Rmail message. | |
537ab246 BG |
30 | |
31 | ;;; Code: | |
32 | ||
33 | (require 'rmail) | |
34 | (require 'mail-parse) | |
35 | ||
f4ce6150 | 36 | ;;; User options. |
537ab246 | 37 | |
f4ce6150 GM |
38 | ;; FIXME should these be in an rmail group? |
39 | ;; FIXME we ought to be able to display images in Emacs. | |
537ab246 BG |
40 | (defcustom rmail-mime-media-type-handlers-alist |
41 | '(("multipart/.*" rmail-mime-multipart-handler) | |
42 | ("text/.*" rmail-mime-text-handler) | |
43 | ("text/\\(x-\\)?patch" rmail-mime-bulk-handler) | |
f4ce6150 GM |
44 | ;; FIXME this handler not defined anywhere? |
45 | ;;; ("application/pgp-signature" rmail-mime-application/pgp-signature-handler) | |
537ab246 | 46 | ("\\(image\\|audio\\|video\\|application\\)/.*" rmail-mime-bulk-handler)) |
f4ce6150 GM |
47 | "Functions to handle various content types. |
48 | This is an alist with elements of the form (REGEXP FUNCTION). | |
49 | REGEXP is a regular expression matching a content-type, and | |
50 | FUNCTION is a handler function to run. It should return non-nil | |
51 | if the job is done." | |
52 | :type '(alist :key-type regexp :value-type (group function)) | |
53 | :version "23.1" | |
537ab246 BG |
54 | :group 'mime) |
55 | ||
56 | (defcustom rmail-mime-attachment-dirs-alist | |
f265b4de | 57 | `(("text/.*" "~/Documents") |
537ab246 | 58 | ("image/.*" "~/Pictures") |
f265b4de | 59 | (".*" "~/Desktop" "~" ,temporary-file-directory)) |
f4ce6150 GM |
60 | "Default directories to save attachments of various types into. |
61 | This is an alist with elements of the form (REGEXP DIR ...). | |
62 | The first item is a regular expression matching a content-type. | |
63 | The remaining elements are directories, in order of decreasing preference. | |
64 | The first directory that exists is used." | |
65 | :type '(alist :key-type regexp :value-type (repeat directory)) | |
66 | :version "23.1" | |
537ab246 BG |
67 | :group 'mime) |
68 | ||
f4ce6150 GM |
69 | ;;; End of user options. |
70 | ||
71 | ||
537ab246 | 72 | (defvar rmail-mime-total-number-of-bulk-attachments 0 |
f4ce6150 GM |
73 | "The total number of bulk attachments in the message. |
74 | If more than 3, offer a way to save all attachments at once.") | |
537ab246 BG |
75 | (put 'rmail-mime-total-number-of-bulk-attachments 'permanent-local t) |
76 | ||
77 | ;;; Buttons | |
78 | ||
79 | (defun rmail-mime-save (button) | |
80 | "Save the attachment using info in the BUTTON." | |
81 | (let* ((filename (button-get button 'filename)) | |
82 | (directory (button-get button 'directory)) | |
83 | (data (button-get button 'data))) | |
84 | (while (file-exists-p (expand-file-name filename directory)) | |
85 | (let* ((f (file-name-sans-extension filename)) | |
86 | (i 1)) | |
87 | (when (string-match "-\\([0-9]+\\)$" f) | |
88 | (setq i (1+ (string-to-number (match-string 1 f))) | |
89 | f (substring f 0 (match-beginning 0)))) | |
90 | (setq filename (concat f "-" (number-to-string i) "." | |
91 | (file-name-extension filename))))) | |
92 | (setq filename (expand-file-name | |
93 | (read-file-name (format "Save as (default: %s): " filename) | |
94 | directory | |
95 | (expand-file-name filename directory)) | |
96 | directory)) | |
97 | (when (file-regular-p filename) | |
98 | (error (message "File `%s' already exists" filename))) | |
99 | (with-temp-file filename | |
100 | (set-buffer-file-coding-system 'no-conversion) | |
101 | (insert data)))) | |
102 | ||
103 | (define-button-type 'rmail-mime-save | |
104 | 'action 'rmail-mime-save) | |
105 | ||
106 | ;;; Handlers | |
107 | ||
108 | (defun rmail-mime-text-handler (content-type | |
109 | content-disposition | |
110 | content-transfer-encoding) | |
111 | "Handle the current buffer as a plain text MIME part." | |
112 | (let* ((charset (cdr (assq 'charset (cdr content-type)))) | |
113 | (coding-system (when charset | |
114 | (intern (downcase charset))))) | |
115 | (when (coding-system-p coding-system) | |
116 | (decode-coding-region (point-min) (point-max) coding-system)))) | |
117 | ||
f4ce6150 | 118 | ;; FIXME move to the test/ directory? |
537ab246 BG |
119 | (defun test-rmail-mime-handler () |
120 | "Test of a mail using no MIME parts at all." | |
121 | (let ((mail "To: alex@gnu.org | |
122 | Content-Type: text/plain; charset=koi8-r | |
123 | Content-Transfer-Encoding: 8bit | |
124 | MIME-Version: 1.0 | |
125 | ||
126 | \372\304\322\301\327\323\324\327\325\312\324\305\41")) | |
127 | (switch-to-buffer (get-buffer-create "*test*")) | |
128 | (erase-buffer) | |
129 | (set-buffer-multibyte nil) | |
130 | (insert mail) | |
131 | (rmail-mime-show t) | |
132 | (set-buffer-multibyte t))) | |
133 | ||
134 | (defun rmail-mime-bulk-handler (content-type | |
135 | content-disposition | |
136 | content-transfer-encoding) | |
137 | "Handle the current buffer as an attachment to download." | |
138 | (setq rmail-mime-total-number-of-bulk-attachments | |
139 | (1+ rmail-mime-total-number-of-bulk-attachments)) | |
140 | ;; Find the default directory for this media type | |
141 | (let* ((directory (catch 'directory | |
142 | (dolist (entry rmail-mime-attachment-dirs-alist) | |
143 | (when (string-match (car entry) (car content-type)) | |
144 | (dolist (dir (cdr entry)) | |
145 | (when (file-directory-p dir) | |
146 | (throw 'directory dir))))))) | |
147 | (filename (or (cdr (assq 'name (cdr content-type))) | |
148 | (cdr (assq 'filename (cdr content-disposition))) | |
149 | "noname")) | |
150 | (label (format "\nAttached %s file: " (car content-type))) | |
151 | (data (buffer-string))) | |
152 | (delete-region (point-min) (point-max)) | |
153 | (insert label) | |
154 | (insert-button filename | |
155 | :type 'rmail-mime-save | |
156 | 'filename filename | |
157 | 'directory directory | |
158 | 'data data))) | |
159 | ||
160 | (defun test-rmail-mime-bulk-handler () | |
161 | "Test of a mail used as an example in RFC 2183." | |
162 | (let ((mail "Content-Type: image/jpeg | |
163 | Content-Disposition: attachment; filename=genome.jpeg; | |
164 | modification-date=\"Wed, 12 Feb 1997 16:29:51 -0500\"; | |
165 | Content-Description: a complete map of the human genome | |
166 | Content-Transfer-Encoding: base64 | |
167 | ||
168 | iVBORw0KGgoAAAANSUhEUgAAADAAAAAwCAMAAABg3Am1AAAABGdBTUEAALGPC/xhBQAAAAZQ | |
169 | TFRF////AAAAVcLTfgAAAPZJREFUeNq9ldsOwzAIQ+3//+l1WlvA5ZLsoUiTto4TB+ISoAjy | |
170 | +ITfRBfcAmgRFFeAm+J6uhdKdFhFWUgDkFsK0oUp/9G2//Kj7Jx+5tSKOdBscgUYiKHRS/me | |
171 | WATQdRUvAK0Bnmshmtn79PpaLBbbOZkjKvRnjRZoRswOkG1wFchKew2g9wXVJVZL/m4+B+vv | |
172 | 9AxQQR2Q33SgAYJzzVACdAWjAfRYzYFO9n6SLnydtQHSMxYDMAKqZ/8FS/lTK+zuq3CtK64L | |
173 | UDwbgUEAUmk2Zyg101d6PhCDySgAvTvDgKiuOrc4dLxUb7UMnhGIexyI+d6U+ABuNAP4Simx | |
174 | lgAAAABJRU5ErkJggg== | |
175 | ")) | |
176 | (switch-to-buffer (get-buffer-create "*test*")) | |
177 | (erase-buffer) | |
178 | (insert mail) | |
179 | (rmail-mime-show))) | |
180 | ||
181 | (defun rmail-mime-multipart-handler (content-type | |
182 | content-disposition | |
183 | content-transfer-encoding) | |
184 | "Handle the current buffer as a multipart MIME body. | |
185 | The current buffer should be narrowed to the body. CONTENT-TYPE, | |
186 | CONTENT-DISPOSITION, and CONTENT-TRANSFER-ENCODING are the values | |
187 | of the respective parsed headers. See `rmail-mime-handle' for their | |
188 | format." | |
189 | ;; Some MUAs start boundaries with "--", while it should start | |
190 | ;; with "CRLF--", as defined by RFC 2046: | |
191 | ;; The boundary delimiter MUST occur at the beginning of a line, | |
192 | ;; i.e., following a CRLF, and the initial CRLF is considered to | |
193 | ;; be attached to the boundary delimiter line rather than part | |
194 | ;; of the preceding part. | |
195 | ;; We currently don't handle that. | |
196 | (let ((boundary (cdr (assq 'boundary content-type))) | |
197 | beg end next) | |
198 | (unless boundary | |
199 | (rmail-mm-get-boundary-error-message | |
200 | "No boundary defined" content-type content-disposition | |
201 | content-transfer-encoding)) | |
202 | (setq boundary (concat "\n--" boundary)) | |
203 | ;; Hide the body before the first bodypart | |
204 | (goto-char (point-min)) | |
205 | (when (and (search-forward boundary nil t) | |
206 | (looking-at "[ \t]*\n")) | |
207 | (delete-region (point-min) (match-end 0))) | |
208 | ;; Reset the counter | |
209 | (setq rmail-mime-total-number-of-bulk-attachments 0) | |
210 | ;; Loop over all body parts, where beg points at the beginning of | |
211 | ;; the part and end points at the end of the part. next points at | |
212 | ;; the beginning of the next part. | |
213 | (setq beg (point-min)) | |
214 | (while (search-forward boundary nil t) | |
215 | (setq end (match-beginning 0)) | |
216 | ;; If this is the last boundary according to RFC 2046, hide the | |
217 | ;; epilogue, else hide the boundary only. Use a marker for | |
218 | ;; `next' because `rmail-mime-show' may change the buffer. | |
219 | (cond ((looking-at "--[ \t]*\n") | |
220 | (setq next (point-max-marker))) | |
221 | ((looking-at "[ \t]*\n") | |
222 | (setq next (copy-marker (match-end 0)))) | |
223 | (t | |
224 | (rmail-mm-get-boundary-error-message | |
225 | "Malformed boundary" content-type content-disposition | |
226 | content-transfer-encoding))) | |
227 | (delete-region end next) | |
228 | ;; Handle the part. | |
229 | (save-match-data | |
230 | (save-excursion | |
231 | (save-restriction | |
232 | (narrow-to-region beg end) | |
233 | (rmail-mime-show)))) | |
234 | (setq beg next) | |
235 | (goto-char beg)))) | |
236 | ||
237 | (defun test-rmail-mime-multipart-handler () | |
238 | "Test of a mail used as an example in RFC 2046." | |
239 | (let ((mail "From: Nathaniel Borenstein <nsb@bellcore.com> | |
240 | To: Ned Freed <ned@innosoft.com> | |
241 | Date: Sun, 21 Mar 1993 23:56:48 -0800 (PST) | |
242 | Subject: Sample message | |
243 | MIME-Version: 1.0 | |
244 | Content-type: multipart/mixed; boundary=\"simple boundary\" | |
245 | ||
246 | This is the preamble. It is to be ignored, though it | |
247 | is a handy place for composition agents to include an | |
248 | explanatory note to non-MIME conformant readers. | |
249 | ||
250 | --simple boundary | |
251 | ||
252 | This is implicitly typed plain US-ASCII text. | |
253 | It does NOT end with a linebreak. | |
254 | --simple boundary | |
255 | Content-type: text/plain; charset=us-ascii | |
256 | ||
257 | This is explicitly typed plain US-ASCII text. | |
258 | It DOES end with a linebreak. | |
259 | ||
260 | --simple boundary-- | |
261 | ||
262 | This is the epilogue. It is also to be ignored.")) | |
263 | (switch-to-buffer (get-buffer-create "*test*")) | |
264 | (erase-buffer) | |
265 | (insert mail) | |
266 | (rmail-mime-show t))) | |
267 | ||
268 | ;;; Main code | |
269 | ||
270 | (defun rmail-mime-handle (content-type | |
271 | content-disposition | |
272 | content-transfer-encoding) | |
273 | "Handle the current buffer as a MIME part. | |
274 | The current buffer should be narrowed to the respective body, and | |
275 | point should be at the beginning of the body. | |
276 | ||
277 | CONTENT-TYPE, CONTENT-DISPOSITION, and CONTENT-TRANSFER-ENCODING | |
278 | are the values of the respective parsed headers. The parsed | |
279 | headers for CONTENT-TYPE and CONTENT-DISPOSITION have the form | |
280 | ||
281 | \(VALUE . ALIST) | |
282 | ||
283 | In other words: | |
284 | ||
285 | \(VALUE (ATTRIBUTE . VALUE) (ATTRIBUTE . VALUE) ...) | |
286 | ||
287 | VALUE is a string and ATTRIBUTE is a symbol. | |
288 | ||
289 | Consider the following header, for example: | |
290 | ||
291 | Content-Type: multipart/mixed; | |
292 | boundary=\"----=_NextPart_000_0104_01C617E4.BDEC4C40\" | |
293 | ||
294 | The parsed header value: | |
295 | ||
296 | \(\"multipart/mixed\" | |
297 | \(\"boundary\" . \"----=_NextPart_000_0104_01C617E4.BDEC4C40\"))" | |
298 | ;; Handle the content transfer encodings we know. Unknown transfer | |
299 | ;; encodings will be passed on to the various handlers. | |
300 | (cond ((string= content-transfer-encoding "base64") | |
301 | (when (ignore-errors | |
302 | (base64-decode-region (point) (point-max))) | |
303 | (setq content-transfer-encoding nil))) | |
304 | ((string= content-transfer-encoding "quoted-printable") | |
305 | (quoted-printable-decode-region (point) (point-max)) | |
306 | (setq content-transfer-encoding nil)) | |
307 | ((string= content-transfer-encoding "8bit") | |
308 | ;; FIXME: Is this the correct way? | |
309 | (set-buffer-multibyte nil))) | |
310 | ;; Inline stuff requires work. Attachments are handled by the bulk | |
311 | ;; handler. | |
312 | (if (string= "inline" (car content-disposition)) | |
313 | (let ((stop nil)) | |
314 | (dolist (entry rmail-mime-media-type-handlers-alist) | |
315 | (when (and (string-match (car entry) (car content-type)) (not stop)) | |
316 | (progn | |
317 | (setq stop (funcall (cadr entry) content-type | |
318 | content-disposition | |
319 | content-transfer-encoding)))))) | |
320 | ;; Everything else is an attachment. | |
321 | (rmail-mime-bulk-handler content-type | |
322 | content-disposition | |
323 | content-transfer-encoding))) | |
324 | ||
325 | (defun rmail-mime-show (&optional show-headers) | |
326 | "Handle the current buffer as a MIME message. | |
327 | If SHOW-HEADERS is non-nil, then the headers of the current part | |
328 | will shown as usual for a MIME message. The headers are also | |
329 | shown for the content type message/rfc822. This function will be | |
330 | called recursively if multiple parts are available. | |
331 | ||
332 | The current buffer must contain a single message. It will be | |
333 | modified." | |
334 | (let ((end (point-min)) | |
335 | content-type | |
336 | content-transfer-encoding | |
337 | content-disposition) | |
338 | ;; `point-min' returns the beginning and `end' points at the end | |
339 | ;; of the headers. | |
340 | (goto-char (point-min)) | |
341 | ;; If we're showing a part without headers, then it will start | |
342 | ;; with a newline. | |
343 | (if (eq (char-after) ?\n) | |
344 | (setq end (1+ (point))) | |
345 | (when (search-forward "\n\n" nil t) | |
346 | (setq end (match-end 0)) | |
347 | (save-restriction | |
348 | (narrow-to-region (point-min) end) | |
349 | ;; FIXME: Default disposition of the multipart entities should | |
350 | ;; be inherited. | |
351 | (setq content-type | |
352 | (mail-fetch-field "Content-Type") | |
353 | content-transfer-encoding | |
354 | (mail-fetch-field "Content-Transfer-Encoding") | |
355 | content-disposition | |
356 | (mail-fetch-field "Content-Disposition"))))) | |
357 | (if content-type | |
358 | (setq content-type (mail-header-parse-content-type | |
359 | content-type)) | |
360 | ;; FIXME: Default "message/rfc822" in a "multipart/digest" | |
361 | ;; according to RFC 2046. | |
362 | (setq content-type '("text/plain"))) | |
363 | (setq content-disposition | |
364 | (if content-disposition | |
365 | (mail-header-parse-content-disposition content-disposition) | |
366 | ;; If none specified, we are free to choose what we deem | |
367 | ;; suitable according to RFC 2183. We like inline. | |
368 | '("inline"))) | |
369 | ;; Unrecognized disposition types are to be treated like | |
370 | ;; attachment according to RFC 2183. | |
371 | (unless (member (car content-disposition) '("inline" "attachment")) | |
372 | (setq content-disposition '("attachment"))) | |
373 | ;; Hide headers and handle the part. | |
374 | (save-restriction | |
375 | (cond ((string= (car content-type) "message/rfc822") | |
376 | (narrow-to-region end (point-max))) | |
377 | ((not show-headers) | |
378 | (delete-region (point-min) end))) | |
379 | (rmail-mime-handle content-type content-disposition | |
380 | content-transfer-encoding)))) | |
381 | ||
73422054 | 382 | ;;;###autoload |
537ab246 | 383 | (defun rmail-mime () |
f4ce6150 GM |
384 | "Process the current Rmail message as a MIME message. |
385 | This creates a temporary \"*RMAIL*\" buffer holding a decoded | |
386 | copy of the message. Content-types are handled according to | |
387 | `rmail-mime-media-type-handlers-alist'. By default, this | |
388 | displays text and multipart messages, and offers to download | |
389 | attachments as specfied by `rmail-mime-attachment-dirs-alist'." | |
537ab246 | 390 | (interactive) |
f4ce6150 | 391 | (let ((data (rmail-apply-in-message rmail-current-message 'buffer-string)) |
537ab246 BG |
392 | (buf (get-buffer-create "*RMAIL*"))) |
393 | (set-buffer buf) | |
f4ce6150 | 394 | (setq buffer-undo-list t) |
537ab246 BG |
395 | (let ((inhibit-read-only t)) |
396 | (erase-buffer) | |
397 | (insert data) | |
f4ce6150 GM |
398 | (rmail-mime-show t) |
399 | (set-buffer-modified-p nil)) | |
537ab246 BG |
400 | (view-buffer buf))) |
401 | ||
402 | (defun rmail-mm-get-boundary-error-message (message type disposition encoding) | |
403 | "Return MESSAGE with more information on the main mime components." | |
404 | (error "%s; type: %s; disposition: %s; encoding: %s" | |
405 | message type disposition encoding)) | |
406 | ||
407 | (provide 'rmailmm) | |
408 | ||
537ab246 BG |
409 | ;; arch-tag: 3f2c5e5d-1aef-4512-bc20-fd737c9d5dd9 |
410 | ;;; rmailmm.el ends here |