lisp/org-id.el

   1 ;;; org-id.el --- Global identifiers for Org-mode entries
   2 ;;
   3 ;; Copyright (C) 2008-2016 Free Software Foundation, Inc.
   4 ;;
   5 ;; Author: Carsten Dominik <carsten at orgmode dot org>
   6 ;; Keywords: outlines, hypermedia, calendar, wp
   7 ;; Homepage: http://orgmode.org
   8 ;;
   9 ;; This file is part of GNU Emacs.
  10 ;;
  11 ;; GNU Emacs is free software: you can redistribute it and/or modify
  12 ;; it under the terms of the GNU General Public License as published by
  13 ;; the Free Software Foundation, either version 3 of the License, or
  14 ;; (at your option) any later version.
  15
  16 ;; GNU Emacs is distributed in the hope that it will be useful,
  17 ;; but WITHOUT ANY WARRANTY; without even the implied warranty of
  18 ;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  19 ;; GNU General Public License for more details.
  20
  21 ;; You should have received a copy of the GNU General Public License
  22 ;; along with GNU Emacs.  If not, see <http://www.gnu.org/licenses/>.
  23 ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
  24 ;;
  25 ;;; Commentary:
  26
  27 ;; This file implements globally unique identifiers for Org-mode entries.
  28 ;; Identifiers are stored in the entry as an :ID: property.  Functions
  29 ;; are provided that create and retrieve such identifiers, and that find
  30 ;; entries based on the identifier.
  31
  32 ;; Identifiers consist of a prefix (default "Org" given by the variable
  33 ;; `org-id-prefix') and a unique part that can be created by a number
  34 ;; of different methods, see the variable `org-id-method'.
  35 ;; Org has a builtin method that uses a compact encoding of the creation
  36 ;; time of the ID, with microsecond accuracy.  This virtually
  37 ;; guarantees globally unique identifiers, even if several people are
  38 ;; creating IDs at the same time in files that will eventually be used
  39 ;; together.
  40 ;;
  41 ;; By default Org uses UUIDs as global unique identifiers.
  42 ;;
  43 ;; This file defines the following API:
  44 ;;
  45 ;; org-id-get-create
  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.
  50 ;;
  51 ;; org-id-get
  52 ;;        Get the ID property of an entry.  Using appropriate arguments
  53 ;;        to the function, it can also create the ID for this entry.
  54 ;;
  55 ;; org-id-goto
  56 ;;        Command to go to a specific ID, this command can be used
  57 ;;        interactively.
  58 ;;
  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.
  62 ;;
  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.
  66 ;;
  67 ;; org-id-find
  68 ;;        Find the location of an entry with specific id.
  69 ;;
  70
  71 ;;; Code:
  72
  73 (require 'org)
  74
  75 (declare-function message-make-fqdn "message" ())
  76 (declare-function org-pop-to-buffer-same-window
  77                   "org-compat" (&optional buffer-or-name norecord label))
  78
  79 ;;; Customization
  80
  81 (defgroup org-id nil
  82   "Options concerning global entry identifiers in Org-mode."
  83   :tag "Org ID"
  84   :group 'org)
  85
  86 (define-obsolete-variable-alias
  87   'org-link-to-org-use-id 'org-id-link-to-org-use-id "24.3")
  88 (defcustom org-id-link-to-org-use-id nil
  89   "Non-nil means storing a link to an Org file will use entry IDs.
  90 \\<org-mode-map>\
  91
  92 The variable can have the following values:
  93
  94 t     Create an ID if needed to make a link to the current entry.
  95
  96 create-if-interactive
  97       If `org-store-link' is called directly (interactively, as a user
  98       command), do create an ID to support the link.  But when doing the
  99       job for capture, only use the ID if it already exists.  The
 100       purpose of this setting is to avoid proliferation of unwanted
 101       IDs, just because you happen to be in an Org file when you
 102       call `org-capture' that automatically and preemptively creates a
 103       link.  If you do want to get an ID link in a capture template to
 104       an entry not having an ID, create it first by explicitly creating
 105       a link to it, using `\\[org-insert-link]' first.
 106
 107 create-if-interactive-and-no-custom-id
 108       Like create-if-interactive, but do not create an ID if there is
 109       a CUSTOM_ID property defined in the entry.
 110
 111 use-existing
 112       Use existing ID, do not create one.
 113
 114 nil   Never use an ID to make a link, instead link using a text search for
 115       the headline text."
 116   :group 'org-link-store
 117   :group 'org-id
 118   :version "24.3"
 119   :type '(choice
 120           (const :tag "Create ID to make link" t)
 121           (const :tag "Create if storing link interactively"
 122                  create-if-interactive)
 123           (const :tag "Create if storing link interactively and no CUSTOM_ID is present"
 124                  create-if-interactive-and-no-custom-id)
 125           (const :tag "Only use existing" use-existing)
 126           (const :tag "Do not use ID to create link" nil)))
 127
 128 (defcustom org-id-uuid-program "uuidgen"
 129   "The uuidgen program."
 130   :group 'org-id
 131   :type 'string)
 132
 133 (defcustom org-id-method 'uuid
 134   "The method that should be used to create new IDs.
 135
 136 An ID will consist of the optional prefix specified in `org-id-prefix',
 137 and a unique part created by the method this variable specifies.
 138
 139 Allowed values are:
 140
 141 org        Org's own internal method, using an encoding of the current time to
 142            microsecond accuracy, and optionally the current domain of the
 143            computer.  See the variable `org-id-include-domain'.
 144
 145 uuid       Create random (version 4) UUIDs.  If the program defined in
 146            `org-id-uuid-program' is available it is used to create the ID.
 147            Otherwise an internal functions is used."
 148   :group 'org-id
 149   :type '(choice
 150           (const :tag "Org's internal method" org)
 151           (const :tag "external: uuidgen" uuid)))
 152
 153 (defcustom org-id-prefix nil
 154   "The prefix for IDs.
 155
 156 This may be a string, or it can be nil to indicate that no prefix is required.
 157 When a string, the string should have no space characters as IDs are expected
 158 to have no space characters in them."
 159   :group 'org-id
 160   :type '(choice
 161           (const :tag "No prefix")
 162           (string :tag "Prefix")))
 163
 164 (defcustom org-id-include-domain nil
 165   "Non-nil means add the domain name to new IDs.
 166 This ensures global uniqueness of IDs, and is also suggested by
 167 RFC 2445 in combination with RFC 822.  This is only relevant if
 168 `org-id-method' is `org'.  When uuidgen is used, the domain will never
 169 be added.
 170 The default is to not use this because we have no really good way to get
 171 the true domain, and Org entries will normally not be shared with enough
 172 people to make this necessary."
 173   :group 'org-id
 174   :type 'boolean)
 175
 176 (defcustom org-id-track-globally t
 177   "Non-nil means track IDs through files, so that links work globally.
 178 This work by maintaining a hash table for IDs and writing this table
 179 to disk when exiting Emacs.  Because of this, it works best if you use
 180 a single Emacs process, not many.
 181
 182 When nil, IDs are not tracked.  Links to IDs will still work within
 183 a buffer, but not if the entry is located in another file.
 184 IDs can still be used if the entry with the id is in the same file as
 185 the link."
 186   :group 'org-id
 187   :type 'boolean)
 188
 189 (defcustom org-id-locations-file (convert-standard-filename
 190                                   (concat user-emacs-directory ".org-id-locations"))
 191   "The file for remembering in which file an ID was defined.
 192 This variable is only relevant when `org-id-track-globally' is set."
 193   :group 'org-id
 194   :type 'file)
 195
 196 (defvar org-id-locations nil
 197   "List of files with IDs in those files.")
 198
 199 (defvar org-id-files nil
 200   "List of files that contain IDs.")
 201
 202 (defcustom org-id-extra-files 'org-agenda-text-search-extra-files
 203   "Files to be searched for IDs, besides the agenda files.
 204 When Org reparses files to remake the list of files and IDs it is tracking,
 205 it will normally scan the agenda files, the archives related to agenda files,
 206 any files that are listed as ID containing in the current register, and
 207 any Org-mode files currently visited by Emacs.
 208 You can list additional files here.
 209 This variable is only relevant when `org-id-track-globally' is set."
 210   :group 'org-id
 211   :type
 212   '(choice
 213     (symbol :tag "Variable")
 214     (repeat :tag "List of files"
 215             (file))))
 216
 217 (defcustom org-id-search-archives t
 218   "Non-nil means search also the archive files of agenda files for entries.
 219 This is a possibility to reduce overhead, but it means that entries moved
 220 to the archives can no longer be found by ID.
 221 This variable is only relevant when `org-id-track-globally' is set."
 222   :group 'org-id
 223   :type 'boolean)
 224
 225 ;;; The API functions
 226
 227 ;;;###autoload
 228 (defun org-id-get-create (&optional force)
 229   "Create an ID for the current entry and return it.
 230 If the entry already has an ID, just return it.
 231 With optional argument FORCE, force the creation of a new ID."
 232   (interactive "P")
 233   (when force
 234     (org-entry-put (point) "ID" nil))
 235   (org-id-get (point) 'create))
 236
 237 ;;;###autoload
 238 (defun org-id-copy ()
 239   "Copy the ID of the entry at point to the kill ring.
 240 Create an ID if necessary."
 241   (interactive)
 242   (org-kill-new (org-id-get nil 'create)))
 243
 244 ;;;###autoload
 245 (defun org-id-get (&optional pom create prefix)
 246   "Get the ID property of the entry at point-or-marker POM.
 247 If POM is nil, refer to the entry at point.
 248 If the entry does not have an ID, the function returns nil.
 249 However, when CREATE is non nil, create an ID if none is present already.
 250 PREFIX will be passed through to `org-id-new'.
 251 In any case, the ID of the entry is returned."
 252   (org-with-point-at pom
 253     (let ((id (org-entry-get nil "ID")))
 254       (cond
 255        ((and id (stringp id) (string-match "\\S-" id))
 256         id)
 257        (create
 258         (setq id (org-id-new prefix))
 259         (org-entry-put pom "ID" id)
 260         (org-id-add-location id (buffer-file-name (buffer-base-buffer)))
 261         id)))))
 262
 263 ;;;###autoload
 264 (defun org-id-get-with-outline-path-completion (&optional targets)
 265   "Use `outline-path-completion' to retrieve the ID of an entry.
 266 TARGETS may be a setting for `org-refile-targets' to define
 267 eligible headlines.  When omitted, all headlines in the current
 268 file are eligible.  This function returns the ID of the entry.
 269 If necessary, the ID is created."
 270   (let* ((org-refile-targets (or targets '((nil . (:maxlevel . 10)))))
 271          (org-refile-use-outline-path
 272           (if (caar org-refile-targets) 'file t))
 273          (org-refile-target-verify-function nil)
 274          (spos (org-refile-get-location "Entry"))
 275          (pom (and spos (move-marker (make-marker) (nth 3 spos)
 276                                      (get-file-buffer (nth 1 spos))))))
 277     (prog1 (org-id-get pom 'create)
 278       (move-marker pom nil))))
 279
 280 ;;;###autoload
 281 (defun org-id-get-with-outline-drilling (&optional targets)
 282   "Use an outline-cycling interface to retrieve the ID of an entry.
 283 This only finds entries in the current buffer, using `org-get-location'.
 284 It returns the ID of the entry.  If necessary, the ID is created."
 285   (let* ((spos (org-get-location (current-buffer) org-goto-help))
 286          (pom (and spos (move-marker (make-marker) (car spos)))))
 287     (prog1 (org-id-get pom 'create)
 288       (move-marker pom nil))))
 289
 290 ;;;###autoload
 291 (defun org-id-goto (id)
 292   "Switch to the buffer containing the entry with id ID.
 293 Move the cursor to that entry in that buffer."
 294   (interactive "sID: ")
 295   (let ((m (org-id-find id 'marker)))
 296     (unless m
 297       (error "Cannot find entry with ID \"%s\"" id))
 298     (org-pop-to-buffer-same-window (marker-buffer m))
 299     (goto-char m)
 300     (move-marker m nil)
 301     (org-show-context)))
 302
 303 ;;;###autoload
 304 (defun org-id-find (id &optional markerp)
 305   "Return the location of the entry with the id ID.
 306 The return value is a cons cell (file-name . position), or nil
 307 if there is no entry with that ID.
 308 With optional argument MARKERP, return the position as a new marker."
 309   (cond
 310    ((symbolp id) (setq id (symbol-name id)))
 311    ((numberp id) (setq id (number-to-string id))))
 312   (let ((file (org-id-find-id-file id))
 313         org-agenda-new-buffers where)
 314     (when file
 315       (setq where (org-id-find-id-in-file id file markerp)))
 316     (unless where
 317       (org-id-update-id-locations nil t)
 318       (setq file (org-id-find-id-file id))
 319       (when file
 320         (setq where (org-id-find-id-in-file id file markerp))))
 321     where))
 322
 323 ;;; Internal functions
 324
 325 ;; Creating new IDs
 326
 327 ;;;###autoload
 328 (defun org-id-new (&optional prefix)
 329   "Create a new globally unique ID.
 330
 331 An ID consists of two parts separated by a colon:
 332 - a prefix
 333 - a unique part that will be created according to `org-id-method'.
 334
 335 PREFIX can specify the prefix, the default is given by the variable
 336 `org-id-prefix'.  However, if PREFIX is the symbol `none', don't use any
 337 prefix even if `org-id-prefix' specifies one.
 338
 339 So a typical ID could look like \"Org:4nd91V40HI\"."
 340   (let* ((prefix (if (eq prefix 'none)
 341                      ""
 342                    (concat (or prefix org-id-prefix) ":")))
 343          unique)
 344     (if (equal prefix ":") (setq prefix ""))
 345     (cond
 346      ((memq org-id-method '(uuidgen uuid))
 347       (setq unique (org-trim (shell-command-to-string org-id-uuid-program)))
 348       (unless (org-uuidgen-p unique)
 349         (setq unique (org-id-uuid))))
 350      ((eq org-id-method 'org)
 351       (let* ((etime (org-reverse-string (org-id-time-to-b36)))
 352              (postfix (if org-id-include-domain
 353                           (progn
 354                             (require 'message)
 355                             (concat "@" (message-make-fqdn))))))
 356         (setq unique (concat etime postfix))))
 357      (t (error "Invalid `org-id-method'")))
 358     (concat prefix unique)))
 359
 360 (defun org-id-uuid ()
 361   "Return string with random (version 4) UUID."
 362   (let ((rnd (md5 (format "%s%s%s%s%s%s%s"
 363                           (random)
 364                           (current-time)
 365                           (user-uid)
 366                           (emacs-pid)
 367                           (user-full-name)
 368                           user-mail-address
 369                           (recent-keys)))))
 370     (format "%s-%s-4%s-%s%s-%s"
 371             (substring rnd 0 8)
 372             (substring rnd 8 12)
 373             (substring rnd 13 16)
 374             (format "%x"
 375                     (logior
 376                      #b10000000
 377                      (logand
 378                       #b10111111
 379                       (string-to-number
 380                        (substring rnd 16 18) 16))))
 381             (substring rnd 18 20)
 382             (substring rnd 20 32))))
 383
 384 (defun org-id-int-to-b36-one-digit (i)
 385   "Turn an integer between 0 and 61 into a single character 0..9, A..Z, a..z."
 386   (cond
 387    ((< i 10) (+ ?0 i))
 388    ((< i 36) (+ ?a i -10))
 389    (t (error "Larger that 35"))))
 390
 391 (defun org-id-b36-to-int-one-digit (i)
 392   "Turn a character 0..9, A..Z, a..z into a number 0..61.
 393 The input I may be a character, or a single-letter string."
 394   (and (stringp i) (setq i (string-to-char i)))
 395   (cond
 396    ((and (>= i ?0) (<= i ?9)) (- i ?0))
 397    ((and (>= i ?a) (<= i ?z)) (+ (- i ?a) 10))
 398    (t (error "Invalid b36 letter"))))
 399
 400 (defun org-id-int-to-b36 (i &optional length)
 401   "Convert an integer to a base-36 number represented as a string."
 402   (let ((s ""))
 403     (while (> i 0)
 404       (setq s (concat (char-to-string
 405                        (org-id-int-to-b36-one-digit (mod i 36))) s)
 406             i (/ i 36)))
 407     (setq length (max 1 (or length 1)))
 408     (if (< (length s) length)
 409         (setq s (concat (make-string (- length (length s)) ?0) s)))
 410     s))
 411
 412 (defun org-id-b36-to-int (s)
 413   "Convert a base-36 string into the corresponding integer."
 414   (let ((r 0))
 415     (mapc (lambda (i) (setq r (+ (* r 36) (org-id-b36-to-int-one-digit i))))
 416           s)
 417     r))
 418
 419 (defun org-id-time-to-b36 (&optional time)
 420   "Encode TIME as a 10-digit string.
 421 This string holds the time to micro-second accuracy, and can be decoded
 422 using `org-id-decode'."
 423   (setq time (or time (current-time)))
 424   (concat (org-id-int-to-b36 (nth 0 time) 4)
 425           (org-id-int-to-b36 (nth 1 time) 4)
 426           (org-id-int-to-b36 (or (nth 2 time) 0) 4)))
 427
 428 (defun org-id-decode (id)
 429   "Split ID into the prefix and the time value that was used to create it.
 430 The return value is (prefix . time) where PREFIX is nil or a string,
 431 and time is the usual three-integer representation of time."
 432   (let (prefix time parts)
 433     (setq parts (org-split-string id ":"))
 434     (if (= 2 (length parts))
 435         (setq prefix (car parts) time (nth 1 parts))
 436       (setq prefix nil time (nth 0 parts)))
 437     (setq time (org-reverse-string time))
 438     (setq time (list (org-id-b36-to-int (substring time 0 4))
 439                      (org-id-b36-to-int (substring time 4 8))
 440                      (org-id-b36-to-int (substring time 8 12))))
 441     (cons prefix time)))
 442
 443 ;; Storing ID locations (files)
 444
 445 ;;;###autoload
 446 (defun org-id-update-id-locations (&optional files silent)
 447   "Scan relevant files for IDs.
 448 Store the relation between files and corresponding IDs.
 449 This will scan all agenda files, all associated archives, and all
 450 files currently mentioned in `org-id-locations'.
 451 When FILES is given, scan these files instead.
 452 When CHECK is given, prepare detailed information about duplicate IDs."
 453   (interactive)
 454   (if (not org-id-track-globally)
 455       (error "Please turn on `org-id-track-globally' if you want to track IDs")
 456     (let* ((org-id-search-archives
 457             (or org-id-search-archives
 458                 (and (symbolp org-id-extra-files)
 459                      (symbol-value org-id-extra-files)
 460                      (member 'agenda-archives org-id-extra-files))))
 461            (files
 462             (or files
 463                 (append
 464                  ;; Agenda files and all associated archives
 465                  (org-agenda-files t org-id-search-archives)
 466                  ;; Explicit extra files
 467                  (if (symbolp org-id-extra-files)
 468                      (symbol-value org-id-extra-files)
 469                    org-id-extra-files)
 470                  ;; Files associated with live org-mode buffers
 471                  (delq nil
 472                        (mapcar (lambda (b)
 473                                  (with-current-buffer b
 474                                    (and (derived-mode-p 'org-mode) (buffer-file-name))))
 475                                (buffer-list)))
 476                  ;; All files known to have IDs
 477                  org-id-files)))
 478            org-agenda-new-buffers
 479            file nfiles tfile ids reg found id seen (ndup 0))
 480       (when (member 'agenda-archives files)
 481         (setq files (delq 'agenda-archives (copy-sequence files))))
 482       (setq nfiles (length files))
 483       (while (setq file (pop files))
 484         (unless silent
 485           (message "Finding ID locations (%d/%d files): %s"
 486                    (- nfiles (length files)) nfiles file))
 487         (setq tfile (file-truename file))
 488         (when (and (file-exists-p file) (not (member tfile seen)))
 489           (push tfile seen)
 490           (setq ids nil)
 491           (with-current-buffer (org-get-agenda-file-buffer file)
 492             (save-excursion
 493               (save-restriction
 494                 (widen)
 495                 (goto-char (point-min))
 496                 (while (re-search-forward "^[ \t]*:ID:[ \t]+\\(\\S-+\\)[ \t]*$"
 497                                           nil t)
 498                   (setq id (org-match-string-no-properties 1))
 499                   (if (member id found)
 500                       (progn
 501                         (message "Duplicate ID \"%s\", also in file %s"
 502                                  id (or (car (delq
 503                                               nil
 504                                               (mapcar
 505                                                (lambda (x)
 506                                                  (if (member id (cdr x))
 507                                                      (car x)))
 508                                                reg)))
 509                                         (buffer-file-name)))
 510                         (when (= ndup 0)
 511                           (ding)
 512                           (sit-for 2))
 513                         (setq ndup (1+ ndup)))
 514                     (push id found)
 515                     (push id ids)))
 516                 (push (cons (abbreviate-file-name file) ids) reg))))))
 517       (org-release-buffers org-agenda-new-buffers)
 518       (setq org-agenda-new-buffers nil)
 519       (setq org-id-locations reg)
 520       (setq org-id-files (mapcar 'car org-id-locations))
 521       (org-id-locations-save) ;; this function can also handle the alist form
 522       ;; now convert to a hash
 523       (setq org-id-locations (org-id-alist-to-hash org-id-locations))
 524       (if (> ndup 0)
 525           (message "WARNING: %d duplicate IDs found, check *Messages* buffer" ndup)
 526         (message "%d unique files scanned for IDs" (length org-id-files)))
 527       org-id-locations)))
 528
 529 (defun org-id-locations-save ()
 530   "Save `org-id-locations' in `org-id-locations-file'."
 531   (when (and org-id-track-globally org-id-locations)
 532     (let ((out (if (hash-table-p org-id-locations)
 533                    (org-id-hash-to-alist org-id-locations)
 534                  org-id-locations)))
 535       (with-temp-file org-id-locations-file
 536         (let ((print-level nil)
 537               (print-length nil))
 538           (print out (current-buffer)))))))
 539
 540 (defun org-id-locations-load ()
 541   "Read the data from `org-id-locations-file'."
 542   (setq org-id-locations nil)
 543   (when org-id-track-globally
 544     (with-temp-buffer
 545       (condition-case nil
 546           (progn
 547             (insert-file-contents-literally org-id-locations-file)
 548             (goto-char (point-min))
 549             (setq org-id-locations (read (current-buffer))))
 550         (error
 551          (message "Could not read org-id-values from %s.  Setting it to nil."
 552                   org-id-locations-file))))
 553     (setq org-id-files (mapcar 'car org-id-locations))
 554     (setq org-id-locations (org-id-alist-to-hash org-id-locations))))
 555
 556 (defun org-id-add-location (id file)
 557   "Add the ID with location FILE to the database of ID locations."
 558   ;; Only if global tracking is on, and when the buffer has a file
 559   (when (and org-id-track-globally id file)
 560     (unless org-id-locations (org-id-locations-load))
 561     (puthash id (abbreviate-file-name file) org-id-locations)
 562     (add-to-list 'org-id-files (abbreviate-file-name file))))
 563
 564 (unless noninteractive
 565   (add-hook 'kill-emacs-hook 'org-id-locations-save))
 566
 567 (defun org-id-hash-to-alist (hash)
 568   "Turn an org-id hash into an alist, so that it can be written to a file."
 569   (let (res x)
 570     (maphash
 571      (lambda (k v)
 572        (if (setq x (member v res))
 573            (setcdr x (cons k (cdr x)))
 574          (push (list v k) res)))
 575      hash)
 576     res))
 577
 578 (defun org-id-alist-to-hash (list)
 579   "Turn an org-id location list into a hash table."
 580   (let ((res (make-hash-table
 581               :test 'equal
 582               :size (apply '+ (mapcar 'length list))))
 583         f)
 584     (mapc
 585      (lambda (x)
 586        (setq f (car x))
 587        (mapc (lambda (i) (puthash i f res)) (cdr x)))
 588      list)
 589     res))
 590
 591 (defun org-id-paste-tracker (txt &optional buffer-or-file)
 592   "Update any IDs in TXT and assign BUFFER-OR-FILE to them."
 593   (when org-id-track-globally
 594     (save-match-data
 595       (setq buffer-or-file (or buffer-or-file (current-buffer)))
 596       (when (bufferp buffer-or-file)
 597         (setq buffer-or-file (or (buffer-base-buffer buffer-or-file)
 598                                  buffer-or-file))
 599         (setq buffer-or-file (buffer-file-name buffer-or-file)))
 600       (when buffer-or-file
 601         (let ((fname (abbreviate-file-name buffer-or-file))
 602               (s 0))
 603           (while (string-match "^[ \t]*:ID:[ \t]+\\([^ \t\n\r]+\\)" txt s)
 604             (setq s (match-end 0))
 605             (org-id-add-location (match-string 1 txt) fname)))))))
 606
 607 ;; Finding entries with specified id
 608
 609 ;;;###autoload
 610 (defun org-id-find-id-file (id)
 611   "Query the id database for the file in which this ID is located."
 612   (unless org-id-locations (org-id-locations-load))
 613   (or (and org-id-locations
 614            (hash-table-p org-id-locations)
 615            (gethash id org-id-locations))
 616       ;; ball back on current buffer
 617       (buffer-file-name (or (buffer-base-buffer (current-buffer))
 618                             (current-buffer)))))
 619
 620 (defun org-id-find-id-in-file (id file &optional markerp)
 621   "Return the position of the entry ID in FILE.
 622 If that files does not exist, or if it does not contain this ID,
 623 return nil.
 624 The position is returned as a cons cell (file-name . position).  With
 625 optional argument MARKERP, return the position as a new marker."
 626   (let (org-agenda-new-buffers buf pos)
 627     (cond
 628      ((not file) nil)
 629      ((not (file-exists-p file)) nil)
 630      (t (with-current-buffer (setq buf (org-get-agenda-file-buffer file))
 631           (setq pos (org-find-entry-with-id id))
 632           (when pos
 633             (if markerp
 634                 (move-marker (make-marker) pos buf)
 635               (cons file pos))))))))
 636
 637 ;; id link type
 638
 639 ;; Calling the following function is hard-coded into `org-store-link',
 640 ;; so we do have to add it to `org-store-link-functions'.
 641
 642 ;;;###autoload
 643 (defun org-id-store-link ()
 644   "Store a link to the current entry, using its ID."
 645   (interactive)
 646   (when (and (buffer-file-name (buffer-base-buffer)) (derived-mode-p 'org-mode))
 647     (let* ((link (concat "id:" (org-id-get-create)))
 648            (case-fold-search nil)
 649            (desc (save-excursion
 650                    (org-back-to-heading t)
 651                    (or (and (looking-at org-complex-heading-regexp)
 652                             (if (match-end 4)
 653                                 (match-string 4)
 654                               (match-string 0)))
 655                        link))))
 656       (org-store-link-props :link link :description desc :type "id")
 657       link)))
 658
 659 (defun org-id-open (id)
 660   "Go to the entry with id ID."
 661   (org-mark-ring-push)
 662   (let ((m (org-id-find id 'marker))
 663         cmd)
 664     (unless m
 665       (error "Cannot find entry with ID \"%s\"" id))
 666     ;; Use a buffer-switching command in analogy to finding files
 667     (setq cmd
 668           (or
 669            (cdr
 670             (assq
 671              (cdr (assq 'file org-link-frame-setup))
 672              '((find-file . switch-to-buffer)
 673                (find-file-other-window . switch-to-buffer-other-window)
 674                (find-file-other-frame . switch-to-buffer-other-frame))))
 675            'switch-to-buffer-other-window))
 676     (if (not (equal (current-buffer) (marker-buffer m)))
 677         (funcall cmd (marker-buffer m)))
 678     (goto-char m)
 679     (move-marker m nil)
 680     (org-show-context)))
 681
 682 (org-add-link-type "id" 'org-id-open)
 683
 684 (provide 'org-id)
 685
 686 ;; Local variables:
 687 ;; generated-autoload-file: "org-loaddefs.el"
 688 ;; End:
 689
 690 ;;; org-id.el ends here