1 ;;; org-id.el --- Global identifiers for Org-mode entries
3 ;; Copyright (C) 2008, 2009 Free Software Foundation, Inc.
5 ;; Author: Carsten Dominik <carsten at orgmode dot org>
6 ;; Keywords: outlines, hypermedia, calendar, wp
7 ;; Homepage: http://orgmode.org
10 ;; This file is part of GNU Emacs.
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.
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.
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 ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
28 ;; This file implements globally unique identifiers for Org-mode entries.
29 ;; Identifiers are stored in the entry as an :ID: property. Functions
30 ;; are provided that create and retrieve such identifiers, and that find
31 ;; entries based on the identifier.
33 ;; Identifiers consist of a prefix (default "Org" given by the variable
34 ;; `org-id-prefix') and a unique part that can be created by a number
35 ;; of different methods, see the variable `org-id-method'.
36 ;; Org has a builtin method that uses a compact encoding of the creation
37 ;; time of the ID, with microsecond accuracy. This virtually
38 ;; guarantees globally unique identifiers, even if several people are
39 ;; creating IDs at the same time in files that will eventually be used
40 ;; together. As an external method `uuidgen' is supported, if installed
43 ;; This file defines the following API:
46 ;; Create an ID for the entry at point if it does not yet have one.
47 ;; Returns the ID (old or new). This function can be used
48 ;; interactively, with prefix argument the creation of a new ID is
49 ;; forced, even if there was an old one.
52 ;; Get the ID property of an entry. Using appropriate arguments
53 ;; to the function, it can also create the ID for this entry.
56 ;; Command to go to a specific ID, this command can be used
59 ;; org-id-get-with-outline-path-completion
60 ;; Retrieve the ID of an entry, using outline path completion.
61 ;; This function can work for multiple files.
63 ;; org-id-get-with-outline-drilling
64 ;; Retrieve the ID of an entry, using outline path completion.
65 ;; This function only works for the current file.
68 ;; Find the location of an entry with specific id.
73 (declare-function message-make-fqdn
"message" ())
78 "Options concerning global entry identifiers in Org-mode."
82 (defcustom org-id-uuid-program
"uuidgen"
83 "The uuidgen program."
87 (defcustom org-id-method
89 (if (string-match "\\`[-0-9a-fA-F]\\{36\\}\\'"
90 (org-trim (shell-command-to-string
91 org-id-uuid-program
)))
95 "The method that should be used to create new IDs.
97 If `uuidgen' is available on the system, it will be used as the default method.
98 if not, the method `org' is used.
99 An ID will consist of the optional prefix specified in `org-id-prefix',
100 and a unique part created by the method this variable specifies.
104 org Org's own internal method, using an encoding of the current time to
105 microsecond accuracy, and optionally the current domain of the
106 computer. See the variable `org-id-include-domain'.
108 uuidgen Call the external command uuidgen."
111 (const :tag
"Org's internal method" org
)
112 (const :tag
"external: uuidgen" uuidgen
)))
114 (defcustom org-id-prefix nil
117 This may be a string, or it can be nil to indicate that no prefix is required.
118 When a string, the string should have no space characters as IDs are expected
119 to have no space characters in them."
122 (const :tag
"No prefix")
123 (string :tag
"Prefix")))
125 (defcustom org-id-include-domain nil
126 "Non-nil means, add the domain name to new IDs.
127 This ensures global uniqueness of IDs, and is also suggested by
128 RFC 2445 in combination with RFC 822. This is only relevant if
129 `org-id-method' is `org'. When uuidgen is used, the domain will never
131 The default is to not use this because we have no really good way to get
132 the true domain, and Org entries will normally not be shared with enough
133 people to make this necessary."
137 (defcustom org-id-track-globally t
138 "Non-nil means, track IDs through files, so that links work globally.
139 This work by maintaining a hash table for IDs and writing this table
140 to disk when exiting Emacs. Because of this, it works best if you use
141 a single Emacs process, not many.
143 When nil, IDs are not tracked. Links to IDs will still work within
144 a buffer, but not if the entry is located in another file.
145 IDs can still be used if the entry with the id is in the same file as
150 (defcustom org-id-locations-file
(convert-standard-filename
151 "~/.emacs.d/.org-id-locations")
152 "The file for remembering in which file an ID was defined.
153 This variable is only relevant when `org-id-track-globally' is set."
157 (defvar org-id-locations nil
158 "List of files with IDs in those files.
159 Depending on `org-id-use-hash' this can also be a hash table mapping IDs
162 (defvar org-id-files nil
163 "List of files that contain IDs.")
165 (defcustom org-id-extra-files
'org-agenda-text-search-extra-files
166 "Files to be searched for IDs, besides the agenda files.
167 When Org reparses files to remake the list of files and IDs it is tracking,
168 it will normally scan the agenda files, the archives related to agenda files,
169 any files that are listed as ID containing in the current register, and
170 any Org-mode files currently visited by Emacs.
171 You can list additional files here.
172 This variable is only relevant when `org-id-track-globally' is set."
176 (symbol :tag
"Variable")
177 (repeat :tag
"List of files"
180 (defcustom org-id-search-archives t
181 "Non-nil means, search also the archive files of agenda files for entries.
182 This is a possibility to reduce overhead, but it means that entries moved
183 to the archives can no longer be found by ID.
184 This variable is only relevant when `org-id-track-globally' is set."
188 ;;; The API functions
191 (defun org-id-get-create (&optional force
)
192 "Create an ID for the current entry and return it.
193 If the entry already has an ID, just return it.
194 With optional argument FORCE, force the creation of a new ID."
197 (org-entry-put (point) "ID" nil
))
198 (org-id-get (point) 'create
))
201 (defun org-id-copy ()
202 "Copy the ID of the entry at point to the kill ring.
203 Create an ID if necessary."
205 (org-kill-new (org-id-get nil
'create
)))
208 (defun org-id-get (&optional pom create prefix
)
209 "Get the ID property of the entry at point-or-marker POM.
210 If POM is nil, refer to the entry at point.
211 If the entry does not have an ID, the function returns nil.
212 However, when CREATE is non nil, create an ID if none is present already.
213 PREFIX will be passed through to `org-id-new'.
214 In any case, the ID of the entry is returned."
215 (org-with-point-at pom
216 (let ((id (org-entry-get nil
"ID")))
218 ((and id
(stringp id
) (string-match "\\S-" id
))
221 (setq id
(org-id-new prefix
))
222 (org-entry-put pom
"ID" id
)
223 (org-id-add-location id
(buffer-file-name (buffer-base-buffer)))
228 (defun org-id-get-with-outline-path-completion (&optional targets
)
229 "Use outline-path-completion to retrieve the ID of an entry.
230 TARGETS may be a setting for `org-refile-targets' to define the eligible
231 headlines. When omitted, all headlines in all agenda files are
233 It returns the ID of the entry. If necessary, the ID is created."
234 (let* ((org-refile-targets (or targets
'((nil .
(:maxlevel .
10)))))
235 (org-refile-use-outline-path
236 (if (caar org-refile-targets
) 'file t
))
237 (org-refile-target-verify-function nil
)
238 (spos (org-refile-get-location "Entry: "))
239 (pom (and spos
(move-marker (make-marker) (nth 3 spos
)
240 (get-file-buffer (nth 1 spos
))))))
241 (prog1 (org-id-get pom
'create
)
242 (move-marker pom nil
))))
245 (defun org-id-get-with-outline-drilling (&optional targets
)
246 "Use an outline-cycling interface to retrieve the ID of an entry.
247 This only finds entries in the current buffer, using `org-get-location'.
248 It returns the ID of the entry. If necessary, the ID is created."
249 (let* ((spos (org-get-location (current-buffer) org-goto-help
))
250 (pom (and spos
(move-marker (make-marker) (car spos
)))))
251 (prog1 (org-id-get pom
'create
)
252 (move-marker pom nil
))))
255 (defun org-id-goto (id)
256 "Switch to the buffer containing the entry with id ID.
257 Move the cursor to that entry in that buffer."
258 (interactive "sID: ")
259 (let ((m (org-id-find id
'marker
)))
261 (error "Cannot find entry with ID \"%s\"" id
))
262 (switch-to-buffer (marker-buffer m
))
268 (defun org-id-find (id &optional markerp
)
269 "Return the location of the entry with the id ID.
270 The return value is a cons cell (file-name . position), or nil
271 if there is no entry with that ID.
272 With optional argument MARKERP, return the position as a new marker."
274 ((symbolp id
) (setq id
(symbol-name id
)))
275 ((numberp id
) (setq id
(number-to-string id
))))
276 (let ((file (org-id-find-id-file id
))
277 org-agenda-new-buffers where
)
279 (setq where
(org-id-find-id-in-file id file markerp
)))
281 (org-id-update-id-locations)
282 (setq file
(org-id-find-id-file id
))
284 (setq where
(org-id-find-id-in-file id file markerp
))))
287 ;;; Internal functions
291 (defun org-id-new (&optional prefix
)
292 "Create a new globally unique ID.
294 An ID consists of two parts separated by a colon:
296 - a unique part that will be created according to `org-id-method'.
298 PREFIX can specify the prefix, the default is given by the variable
299 `org-id-prefix'. However, if PREFIX is the symbol `none', don't use any
300 prefix even if `org-id-prefix' specifies one.
302 So a typical ID could look like \"Org:4nd91V40HI\"."
303 (let* ((prefix (if (eq prefix
'none
)
305 (concat (or prefix org-id-prefix
) ":")))
307 (if (equal prefix
":") (setq prefix
""))
309 ((eq org-id-method
'uuidgen
)
310 (setq unique
(org-trim (shell-command-to-string org-id-uuid-program
))))
311 ((eq org-id-method
'org
)
312 (let* ((etime (org-id-reverse-string (org-id-time-to-b36)))
313 (postfix (if org-id-include-domain
316 (concat "@" (message-make-fqdn))))))
317 (setq unique
(concat etime postfix
))))
318 (t (error "Invalid `org-id-method'")))
319 (concat prefix unique
)))
321 (defun org-id-reverse-string (s)
322 (mapconcat 'char-to-string
(nreverse (string-to-list s
)) ""))
324 (defun org-id-int-to-b36-one-digit (i)
325 "Turn an integer between 0 and 61 into a single character 0..9, A..Z, a..z."
328 ((< i
36) (+ ?a i -
10))
329 (t (error "Larger that 35"))))
331 (defun org-id-b36-to-int-one-digit (i)
332 "Turn a character 0..9, A..Z, a..z into a number 0..61.
333 The input I may be a character, or a single-letter string."
334 (and (stringp i
) (setq i
(string-to-char i
)))
336 ((and (>= i ?
0) (<= i ?
9)) (- i ?
0))
337 ((and (>= i ?a
) (<= i ?z
)) (+ (- i ?a
) 10))
338 (t (error "Invalid b36 letter"))))
340 (defun org-id-int-to-b36 (i &optional length
)
341 "Convert an integer to a base-36 number represented as a string."
344 (setq s
(concat (char-to-string
345 (org-id-int-to-b36-one-digit (mod i
36))) s
)
347 (setq length
(max 1 (or length
1)))
348 (if (< (length s
) length
)
349 (setq s
(concat (make-string (- length
(length s
)) ?
0) s
)))
352 (defun org-id-b36-to-int (s)
353 "Convert a base-36 string into the corresponding integer."
355 (mapc (lambda (i) (setq r
(+ (* r
36) (org-id-b36-to-int-one-digit i
))))
359 (defun org-id-time-to-b36 (&optional time
)
360 "Encode TIME as a 10-digit string.
361 This string holds the time to micro-second accuracy, and can be decoded
362 using `org-id-decode'."
363 (setq time
(or time
(current-time)))
364 (concat (org-id-int-to-b36 (nth 0 time
) 4)
365 (org-id-int-to-b36 (nth 1 time
) 4)
366 (org-id-int-to-b36 (or (nth 2 time
) 0) 4)))
368 (defun org-id-decode (id)
369 "Split ID into the prefix and the time value that was used to create it.
370 The return value is (prefix . time) where PREFIX is nil or a string,
371 and time is the usual three-integer representation of time."
372 (let (prefix time parts
)
373 (setq parts
(org-split-string id
":"))
374 (if (= 2 (length parts
))
375 (setq prefix
(car parts
) time
(nth 1 parts
))
376 (setq prefix nil time
(nth 0 parts
)))
377 (setq time
(org-id-reverse-string time
))
378 (setq time
(list (org-id-b36-to-int (substring time
0 4))
379 (org-id-b36-to-int (substring time
4 8))
380 (org-id-b36-to-int (substring time
8 12))))
383 ;; Storing ID locations (files)
385 (defun org-id-update-id-locations (&optional files
)
386 "Scan relevant files for IDs.
387 Store the relation between files and corresponding IDs.
388 This will scan all agenda files, all associated archives, and all
389 files currently mentioned in `org-id-locations'.
390 When FILES is given, scan these files instead.
391 When CHECK is given, prepare detailed information about duplicate IDs."
393 (if (not org-id-track-globally
)
394 (error "Please turn on `org-id-track-globally' if you want to track IDs")
398 ;; Agenda files and all associated archives
399 (org-agenda-files t org-id-search-archives
)
400 ;; Explicit extra files
401 (if (symbolp org-id-extra-files
)
402 (symbol-value org-id-extra-files
)
404 ;; Files associated with live org-mode buffers
407 (with-current-buffer b
408 (and (org-mode-p) (buffer-file-name))))
410 ;; All files known to have IDs
412 org-agenda-new-buffers
413 file nfiles tfile ids reg found id seen
(ndup 0))
414 (setq nfiles
(length files
))
415 (while (setq file
(pop files
))
416 (message "Finding ID locations (%d/%d files): %s"
417 (- nfiles
(length files
)) nfiles file
)
418 (setq tfile
(file-truename file
))
419 (when (and (file-exists-p file
) (not (member tfile seen
)))
422 (with-current-buffer (org-get-agenda-file-buffer file
)
426 (goto-char (point-min))
427 (while (re-search-forward "^[ \t]*:ID:[ \t]+\\(\\S-+\\)[ \t]*$"
429 (setq id
(org-match-string-no-properties 1))
430 (if (member id found
)
432 (message "Duplicate ID \"%s\", also in file %s"
437 (if (member id
(cdr x
)) (car x
)))
442 (setq ndup
(1+ ndup
)))
445 (push (cons (abbreviate-file-name file
) ids
) reg
))))))
446 (org-release-buffers org-agenda-new-buffers
)
447 (setq org-agenda-new-buffers nil
)
448 (setq org-id-locations reg
)
449 (setq org-id-files
(mapcar 'car org-id-locations
))
450 (org-id-locations-save) ;; this function can also handle the alist form
451 ;; now convert to a hash
452 (setq org-id-locations
(org-id-alist-to-hash org-id-locations
))
454 (message "WARNING: %d duplicate IDs found, check *Messages* buffer" ndup
)
455 (message "%d unique files scanned for IDs" (length org-id-files
)))
458 (defun org-id-locations-save ()
459 "Save `org-id-locations' in `org-id-locations-file'."
460 (when org-id-track-globally
461 (let ((out (if (hash-table-p org-id-locations
)
462 (org-id-hash-to-alist org-id-locations
)
464 (with-temp-file org-id-locations-file
465 (print out
(current-buffer))))))
467 (defun org-id-locations-load ()
468 "Read the data from `org-id-locations-file'."
469 (setq org-id-locations nil
)
470 (when org-id-track-globally
474 (insert-file-contents-literally org-id-locations-file
)
475 (goto-char (point-min))
476 (setq org-id-locations
(read (current-buffer))))
478 (message "Could not read org-id-values from %s. Setting it to nil."
479 org-id-locations-file
))))
480 (setq org-id-files
(mapcar 'car org-id-locations
))
481 (setq org-id-locations
(org-id-alist-to-hash org-id-locations
))))
483 (defun org-id-add-location (id file
)
484 "Add the ID with location FILE to the database of ID locations."
485 ;; Only if global tracking is on, and when the buffer has a file
486 (when (and org-id-track-globally id file
)
487 (unless org-id-locations
(org-id-locations-load))
488 (puthash id
(abbreviate-file-name file
) org-id-locations
)
489 (add-to-list 'org-id-files
(abbreviate-file-name file
))))
491 (add-hook 'kill-emacs-hook
'org-id-locations-save
)
493 (defun org-id-hash-to-alist (hash)
494 "Turn an org-id hash into an alist, so that it can be written to a file."
498 (if (setq x
(member v res
))
499 (setcdr x
(cons k
(cdr x
)))
500 (push (list v k
) res
)))
504 (defun org-id-alist-to-hash (list)
505 "Turn an org-id location list into a hash table."
506 (let ((res (make-hash-table
508 :size
(apply '+ (mapcar 'length list
))))
513 (mapc (lambda (i) (puthash i f res
)) (cdr x
)))
517 (defun org-id-paste-tracker (txt &optional buffer-or-file
)
518 "Update any IDs in TXT and assign BUFFER-OR-FILE to them."
519 (when org-id-track-globally
521 (setq buffer-or-file
(or buffer-or-file
(current-buffer)))
522 (when (bufferp buffer-or-file
)
523 (setq buffer-or-file
(or (buffer-base-buffer buffer-or-file
)
525 (setq buffer-or-file
(buffer-file-name buffer-or-file
)))
527 (let ((fname (abbreviate-file-name buffer-or-file
))
529 (while (string-match "^[ \t]*:ID:[ \t]+\\([^ \t\n\r]+\\)" txt s
)
530 (setq s
(match-end 0))
531 (org-id-add-location (match-string 1 txt
) fname
)))))))
533 ;; Finding entries with specified id
536 (defun org-id-find-id-file (id)
537 "Query the id database for the file in which this ID is located."
538 (unless org-id-locations
(org-id-locations-load))
539 (or (gethash id org-id-locations
)
540 ;; ball back on current buffer
541 (buffer-file-name (or (buffer-base-buffer (current-buffer))
544 (defun org-id-find-id-in-file (id file
&optional markerp
)
545 "Return the position of the entry ID in FILE.
546 If that files does not exist, or if it does not contain this ID,
548 The position is returned as a cons cell (file-name . position). With
549 optional argument MARKERP, return the position as a new marker."
550 (let (org-agenda-new-buffers buf pos
)
553 ((not (file-exists-p file
)) nil
)
554 (t (with-current-buffer (setq buf
(org-get-agenda-file-buffer file
))
555 (setq pos
(org-find-entry-with-id id
))
558 (move-marker (make-marker) pos buf
)
559 (cons file pos
))))))))
563 ;; Calling the following function is hard-coded into `org-store-link',
564 ;; so we do have to add it to `org-store-link-functions'.
566 (defun org-id-store-link ()
567 "Store a link to the current entry, using its ID."
569 (let* ((link (org-make-link "id:" (org-id-get-create)))
570 (desc (save-excursion
571 (org-back-to-heading t
)
572 (or (and (looking-at org-complex-heading-regexp
)
573 (if (match-end 4) (match-string 4) (match-string 0)))
575 (org-store-link-props :link link
:description desc
:type
"id")
578 (defun org-id-open (id)
579 "Go to the entry with id ID."
581 (let ((m (org-id-find id
'marker
))
584 (error "Cannot find entry with ID \"%s\"" id
))
585 ;; Use a buffer-switching command in analogy to finding files
590 (cdr (assq 'file org-link-frame-setup
))
591 '((find-file . switch-to-buffer
)
592 (find-file-other-window . switch-to-buffer-other-window
)
593 (find-file-other-frame . switch-to-buffer-other-frame
))))
594 'switch-to-buffer-other-window
))
595 (if (not (equal (current-buffer) (marker-buffer m
)))
596 (funcall cmd
(marker-buffer m
)))
601 (org-add-link-type "id" 'org-id-open
)
605 ;;; org-id.el ends here
607 ;; arch-tag: e5abaca4-e16f-4b25-832a-540cfb63a712