lisp/ox-icalendar.el

   1 ;;; ox-icalendar.el --- iCalendar Back-End for Org Export Engine -*- lexical-binding: t; -*-
   2
   3 ;; Copyright (C) 2004-2017 Free Software Foundation, Inc.
   4
   5 ;; Author: Carsten Dominik <carsten at orgmode dot org>
   6 ;;      Nicolas Goaziou <n dot goaziou at gmail dot com>
   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 <https://www.gnu.org/licenses/>.
  24
  25 ;;; Commentary:
  26 ;;
  27 ;; This library implements an iCalendar back-end for Org generic
  28 ;; exporter.  See Org manual for more information.
  29 ;;
  30 ;; It is expected to conform to RFC 5545.
  31
  32 ;;; Code:
  33
  34 (require 'cl-lib)
  35 (require 'ox-ascii)
  36 (declare-function org-bbdb-anniv-export-ical "org-bbdb" nil)
  37
  38
  39 \f
  40 ;;; User-Configurable Variables
  41
  42 (defgroup org-export-icalendar nil
  43   "Options specific for iCalendar export back-end."
  44   :tag "Org Export iCalendar"
  45   :group 'org-export)
  46
  47 (defcustom org-icalendar-combined-agenda-file "~/org.ics"
  48   "The file name for the iCalendar file covering all agenda files.
  49 This file is created with the command `\\[org-icalendar-combine-agenda-files]'.
  50 The file name should be absolute.  It will be overwritten without warning."
  51   :group 'org-export-icalendar
  52   :type 'file)
  53
  54 (defcustom org-icalendar-alarm-time 0
  55   "Number of minutes for triggering an alarm for exported timed events.
  56
  57 A zero value (the default) turns off the definition of an alarm trigger
  58 for timed events.  If non-zero, alarms are created.
  59
  60 - a single alarm per entry is defined
  61 - The alarm will go off N minutes before the event
  62 - only a DISPLAY action is defined."
  63   :group 'org-export-icalendar
  64   :version "24.1"
  65   :type 'integer)
  66
  67 (defcustom org-icalendar-combined-name "OrgMode"
  68   "Calendar name for the combined iCalendar representing all agenda files."
  69   :group 'org-export-icalendar
  70   :type 'string)
  71
  72 (defcustom org-icalendar-combined-description ""
  73   "Calendar description for the combined iCalendar (all agenda files)."
  74   :group 'org-export-icalendar
  75   :type 'string)
  76
  77 (defcustom org-icalendar-exclude-tags nil
  78   "Tags that exclude a tree from export.
  79 This variable allows specifying different exclude tags from other
  80 back-ends.  It can also be set with the ICALENDAR_EXCLUDE_TAGS
  81 keyword."
  82   :group 'org-export-icalendar
  83   :type '(repeat (string :tag "Tag")))
  84
  85 (defcustom org-icalendar-use-deadline '(event-if-not-todo todo-due)
  86   "Contexts where iCalendar export should use a deadline time stamp.
  87
  88 This is a list with possibly several symbols in it.  Valid symbols are:
  89
  90 `event-if-todo'       Deadlines in TODO entries become calendar events.
  91 `event-if-not-todo'   Deadlines in non-TODO entries become calendar events.
  92 `todo-due'            Use deadlines in TODO entries as due-dates."
  93   :group 'org-export-icalendar
  94   :type '(set :greedy t
  95               (const :tag "Deadlines in non-TODO entries become events"
  96                      event-if-not-todo)
  97               (const :tag "Deadline in TODO entries become events"
  98                      event-if-todo)
  99               (const :tag "Deadlines in TODO entries become due-dates"
 100                      todo-due)))
 101
 102 (defcustom org-icalendar-use-scheduled '(todo-start)
 103   "Contexts where iCalendar export should use a scheduling time stamp.
 104
 105 This is a list with possibly several symbols in it.  Valid symbols are:
 106
 107 `event-if-todo'       Scheduling time stamps in TODO entries become an event.
 108 `event-if-not-todo'   Scheduling time stamps in non-TODO entries become an event.
 109 `todo-start'          Scheduling time stamps in TODO entries become start date.
 110                       Some calendar applications show TODO entries only after
 111                       that date."
 112   :group 'org-export-icalendar
 113   :type '(set :greedy t
 114               (const :tag
 115                      "SCHEDULED timestamps in non-TODO entries become events"
 116                      event-if-not-todo)
 117               (const :tag "SCHEDULED timestamps in TODO entries become events"
 118                      event-if-todo)
 119               (const :tag "SCHEDULED in TODO entries become start date"
 120                      todo-start)))
 121
 122 (defcustom org-icalendar-categories '(local-tags category)
 123   "Items that should be entered into the \"categories\" field.
 124
 125 This is a list of symbols, the following are valid:
 126 `category'    The Org mode category of the current file or tree
 127 `todo-state'  The todo state, if any
 128 `local-tags'  The tags, defined in the current line
 129 `all-tags'    All tags, including inherited ones."
 130   :group 'org-export-icalendar
 131   :type '(repeat
 132           (choice
 133            (const :tag "The file or tree category" category)
 134            (const :tag "The TODO state" todo-state)
 135            (const :tag "Tags defined in current line" local-tags)
 136            (const :tag "All tags, including inherited ones" all-tags))))
 137
 138 (defcustom org-icalendar-with-timestamps 'active
 139   "Non-nil means make an event from plain time stamps.
 140
 141 It can be set to `active', `inactive', t or nil, in order to make
 142 an event from, respectively, only active timestamps, only
 143 inactive ones, all of them or none.
 144
 145 This variable has precedence over `org-export-with-timestamps'.
 146 It can also be set with the #+OPTIONS line, e.g. \"<:t\"."
 147   :group 'org-export-icalendar
 148   :type '(choice
 149           (const :tag "All timestamps" t)
 150           (const :tag "Only active timestamps" active)
 151           (const :tag "Only inactive timestamps" inactive)
 152           (const :tag "No timestamp" nil)))
 153
 154 (defcustom org-icalendar-include-todo nil
 155   "Non-nil means create VTODO components from TODO items.
 156
 157 Valid values are:
 158 nil                  don't include any task.
 159 t                    include tasks that are not in DONE state.
 160 `unblocked'          include all TODO items that are not blocked.
 161 `all'                include both done and not done items."
 162   :group 'org-export-icalendar
 163   :type '(choice
 164           (const :tag "None" nil)
 165           (const :tag "Unfinished" t)
 166           (const :tag "Unblocked" unblocked)
 167           (const :tag "All" all)
 168           (repeat :tag "Specific TODO keywords"
 169                   (string :tag "Keyword"))))
 170
 171 (defcustom org-icalendar-include-bbdb-anniversaries nil
 172   "Non-nil means a combined iCalendar file should include anniversaries.
 173 The anniversaries are defined in the BBDB database."
 174   :group 'org-export-icalendar
 175   :type 'boolean)
 176
 177 (defcustom org-icalendar-include-sexps t
 178   "Non-nil means export to iCalendar files should also cover sexp entries.
 179 These are entries like in the diary, but directly in an Org file."
 180   :group 'org-export-icalendar
 181   :type 'boolean)
 182
 183 (defcustom org-icalendar-include-body t
 184   "Amount of text below headline to be included in iCalendar export.
 185 This is a number of characters that should maximally be included.
 186 Properties, scheduling and clocking lines will always be removed.
 187 The text will be inserted into the DESCRIPTION field."
 188   :group 'org-export-icalendar
 189   :type '(choice
 190           (const :tag "Nothing" nil)
 191           (const :tag "Everything" t)
 192           (integer :tag "Max characters")))
 193
 194 (defcustom org-icalendar-store-UID nil
 195   "Non-nil means store any created UIDs in properties.
 196
 197 The iCalendar standard requires that all entries have a unique identifier.
 198 Org will create these identifiers as needed.  When this variable is non-nil,
 199 the created UIDs will be stored in the ID property of the entry.  Then the
 200 next time this entry is exported, it will be exported with the same UID,
 201 superseding the previous form of it.  This is essential for
 202 synchronization services.
 203
 204 This variable is not turned on by default because we want to avoid creating
 205 a property drawer in every entry if people are only playing with this feature,
 206 or if they are only using it locally."
 207   :group 'org-export-icalendar
 208   :type 'boolean)
 209
 210 (defcustom org-icalendar-timezone (getenv "TZ")
 211   "The time zone string for iCalendar export.
 212 When nil or the empty string, use output
 213 from (current-time-zone)."
 214   :group 'org-export-icalendar
 215   :type '(choice
 216           (const :tag "Unspecified" nil)
 217           (string :tag "Time zone")))
 218
 219 (defcustom org-icalendar-date-time-format ":%Y%m%dT%H%M%S"
 220   "Format-string for exporting icalendar DATE-TIME.
 221
 222 See `format-time-string' for a full documentation.  The only
 223 difference is that `org-icalendar-timezone' is used for %Z.
 224
 225 Interesting value are:
 226  - \":%Y%m%dT%H%M%S\" for local time
 227  - \";TZID=%Z:%Y%m%dT%H%M%S\" for local time with explicit timezone
 228  - \":%Y%m%dT%H%M%SZ\" for time expressed in Universal Time"
 229   :group 'org-export-icalendar
 230   :version "24.1"
 231   :type '(choice
 232           (const :tag "Local time" ":%Y%m%dT%H%M%S")
 233           (const :tag "Explicit local time" ";TZID=%Z:%Y%m%dT%H%M%S")
 234           (const :tag "Universal time" ":%Y%m%dT%H%M%SZ")
 235           (string :tag "Explicit format")))
 236
 237 (defvar org-icalendar-after-save-hook nil
 238   "Hook run after an iCalendar file has been saved.
 239 This hook is run with the name of the file as argument.  A good
 240 way to use this is to tell a desktop calendar application to
 241 re-read the iCalendar file.")
 242
 243
 244 \f
 245 ;;; Define Back-End
 246
 247 (org-export-define-derived-backend 'icalendar 'ascii
 248   :translate-alist '((clock . ignore)
 249                      (footnote-definition . ignore)
 250                      (footnote-reference . ignore)
 251                      (headline . org-icalendar-entry)
 252                      (inlinetask . ignore)
 253                      (planning . ignore)
 254                      (section . ignore)
 255                      (inner-template . (lambda (c i) c))
 256                      (template . org-icalendar-template))
 257   :options-alist
 258   '((:exclude-tags
 259      "ICALENDAR_EXCLUDE_TAGS" nil org-icalendar-exclude-tags split)
 260     (:with-timestamps nil "<" org-icalendar-with-timestamps)
 261     ;; Other variables.
 262     (:icalendar-alarm-time nil nil org-icalendar-alarm-time)
 263     (:icalendar-categories nil nil org-icalendar-categories)
 264     (:icalendar-date-time-format nil nil org-icalendar-date-time-format)
 265     (:icalendar-include-bbdb-anniversaries nil nil org-icalendar-include-bbdb-anniversaries)
 266     (:icalendar-include-body nil nil org-icalendar-include-body)
 267     (:icalendar-include-sexps nil nil org-icalendar-include-sexps)
 268     (:icalendar-include-todo nil nil org-icalendar-include-todo)
 269     (:icalendar-store-UID nil nil org-icalendar-store-UID)
 270     (:icalendar-timezone nil nil org-icalendar-timezone)
 271     (:icalendar-use-deadline nil nil org-icalendar-use-deadline)
 272     (:icalendar-use-scheduled nil nil org-icalendar-use-scheduled))
 273   :filters-alist
 274   '((:filter-headline . org-icalendar-clear-blank-lines))
 275   :menu-entry
 276   '(?c "Export to iCalendar"
 277        ((?f "Current file" org-icalendar-export-to-ics)
 278         (?a "All agenda files"
 279             (lambda (a s v b) (org-icalendar-export-agenda-files a)))
 280         (?c "Combine all agenda files"
 281             (lambda (a s v b) (org-icalendar-combine-agenda-files a))))))
 282
 283
 284 \f
 285 ;;; Internal Functions
 286
 287 (defun org-icalendar-create-uid (file &optional bell)
 288   "Set ID property on headlines missing it in FILE.
 289 When optional argument BELL is non-nil, inform the user with
 290 a message if the file was modified."
 291   (let (modified-flag)
 292     (org-map-entries
 293      (lambda ()
 294        (let ((entry (org-element-at-point)))
 295          (unless (org-element-property :ID entry)
 296            (org-id-get-create)
 297            (setq modified-flag t)
 298            (forward-line))))
 299      nil nil 'comment)
 300     (when (and bell modified-flag)
 301       (message "ID properties created in file \"%s\"" file)
 302       (sit-for 2))))
 303
 304 (defun org-icalendar-blocked-headline-p (headline info)
 305   "Non-nil when HEADLINE is considered to be blocked.
 306
 307 INFO is a plist used as a communication channel.
 308
 309 A headline is blocked when either
 310
 311   - it has children which are not all in a completed state;
 312
 313   - it has a parent with the property :ORDERED:, and there are
 314     siblings prior to it with incomplete status;
 315
 316   - its parent is blocked because it has siblings that should be
 317     done first or is a child of a blocked grandparent entry."
 318   (or
 319    ;; Check if any child is not done.
 320    (org-element-map headline 'headline
 321      (lambda (hl) (eq (org-element-property :todo-type hl) 'todo))
 322      info 'first-match)
 323    ;; Check :ORDERED: node property.
 324    (catch 'blockedp
 325      (let ((current headline))
 326        (dolist (parent (org-element-lineage headline))
 327          (cond
 328           ((not (org-element-property :todo-keyword parent))
 329            (throw 'blockedp nil))
 330           ((org-not-nil (org-element-property :ORDERED parent))
 331            (let ((sibling current))
 332              (while (setq sibling (org-export-get-previous-element
 333                                    sibling info))
 334                (when (eq (org-element-property :todo-type sibling) 'todo)
 335                  (throw 'blockedp t)))))
 336           (t (setq current parent))))))))
 337
 338 (defun org-icalendar-use-UTC-date-time-p ()
 339   "Non-nil when `org-icalendar-date-time-format' requires UTC time."
 340   (char-equal (elt org-icalendar-date-time-format
 341                    (1- (length org-icalendar-date-time-format))) ?Z))
 342
 343 (defvar org-agenda-default-appointment-duration) ; From org-agenda.el.
 344 (defun org-icalendar-convert-timestamp (timestamp keyword &optional end tz)
 345   "Convert TIMESTAMP to iCalendar format.
 346
 347 TIMESTAMP is a timestamp object.  KEYWORD is added in front of
 348 it, in order to make a complete line (e.g. \"DTSTART\").
 349
 350 When optional argument END is non-nil, use end of time range.
 351 Also increase the hour by two (if time string contains a time),
 352 or the day by one (if it does not contain a time) when no
 353 explicit ending time is specified.
 354
 355 When optional argument TZ is non-nil, timezone data time will be
 356 added to the timestamp.  It can be the string \"UTC\", to use UTC
 357 time, or a string in the IANA TZ database
 358 format (e.g. \"Europe/London\").  In either case, the value of
 359 `org-icalendar-date-time-format' will be ignored."
 360   (let* ((year-start (org-element-property :year-start timestamp))
 361          (year-end (org-element-property :year-end timestamp))
 362          (month-start (org-element-property :month-start timestamp))
 363          (month-end (org-element-property :month-end timestamp))
 364          (day-start (org-element-property :day-start timestamp))
 365          (day-end (org-element-property :day-end timestamp))
 366          (hour-start (org-element-property :hour-start timestamp))
 367          (hour-end (org-element-property :hour-end timestamp))
 368          (minute-start (org-element-property :minute-start timestamp))
 369          (minute-end (org-element-property :minute-end timestamp))
 370          (with-time-p minute-start)
 371          (equal-bounds-p
 372           (equal (list year-start month-start day-start hour-start minute-start)
 373                  (list year-end month-end day-end hour-end minute-end)))
 374          (mi (cond ((not with-time-p) 0)
 375                    ((not end) minute-start)
 376                    ((and org-agenda-default-appointment-duration equal-bounds-p)
 377                     (+ minute-end org-agenda-default-appointment-duration))
 378                    (t minute-end)))
 379          (h (cond ((not with-time-p) 0)
 380                   ((not end) hour-start)
 381                   ((or (not equal-bounds-p)
 382                        org-agenda-default-appointment-duration)
 383                    hour-end)
 384                   (t (+ hour-end 2))))
 385          (d (cond ((not end) day-start)
 386                   ((not with-time-p) (1+ day-end))
 387                   (t day-end)))
 388          (m (if end month-end month-start))
 389          (y (if end year-end year-start)))
 390     (concat
 391      keyword
 392      (format-time-string
 393       (cond ((string-equal tz "UTC") ":%Y%m%dT%H%M%SZ")
 394             ((not with-time-p) ";VALUE=DATE:%Y%m%d")
 395             ((stringp tz) (concat ";TZID=" tz ":%Y%m%dT%H%M%S"))
 396             (t (replace-regexp-in-string "%Z"
 397                                          org-icalendar-timezone
 398                                          org-icalendar-date-time-format
 399                                          t)))
 400       ;; Convert timestamp into internal time in order to use
 401       ;; `format-time-string' and fix any mistake (i.e. MI >= 60).
 402       (encode-time 0 mi h d m y)
 403       (and (or (string-equal tz "UTC")
 404                (and (null tz)
 405                     with-time-p
 406                     (org-icalendar-use-UTC-date-time-p)))
 407            t)))))
 408
 409 (defun org-icalendar-dtstamp ()
 410   "Return DTSTAMP property, as a string."
 411   (format-time-string "DTSTAMP:%Y%m%dT%H%M%SZ" nil t))
 412
 413 (defun org-icalendar-get-categories (entry info)
 414   "Return categories according to `org-icalendar-categories'.
 415 ENTRY is a headline or an inlinetask element.  INFO is a plist
 416 used as a communication channel."
 417   (mapconcat
 418    #'identity
 419    (org-uniquify
 420     (let (categories)
 421       (dolist (type org-icalendar-categories (nreverse categories))
 422         (cl-case type
 423           (category
 424            (push (org-export-get-category entry info) categories))
 425           (todo-state
 426            (let ((todo (org-element-property :todo-keyword entry)))
 427              (and todo (push todo categories))))
 428           (local-tags
 429            (setq categories
 430                  (append (nreverse (org-export-get-tags entry info))
 431                          categories)))
 432           (all-tags
 433            (setq categories
 434                  (append (nreverse (org-export-get-tags entry info nil t))
 435                          categories)))))))
 436    ","))
 437
 438 (defun org-icalendar-transcode-diary-sexp (sexp uid summary)
 439   "Transcode a diary sexp into iCalendar format.
 440 SEXP is the diary sexp being transcoded, as a string.  UID is the
 441 unique identifier for the entry.  SUMMARY defines a short summary
 442 or subject for the event."
 443   (when (require 'icalendar nil t)
 444     (org-element-normalize-string
 445      (with-temp-buffer
 446        (let ((sexp (if (not (string-match "\\`<%%" sexp)) sexp
 447                      (concat (substring sexp 1 -1) " " summary))))
 448          (put-text-property 0 1 'uid uid sexp)
 449          (insert sexp "\n"))
 450        (org-diary-to-ical-string (current-buffer))))))
 451
 452 (defun org-icalendar-cleanup-string (s)
 453   "Cleanup string S according to RFC 5545."
 454   (when s
 455     ;; Protect "\", "," and ";" characters. and replace newline
 456     ;; characters with literal \n.
 457     (replace-regexp-in-string
 458      "[ \t]*\n" "\\n"
 459      (replace-regexp-in-string "[\\,;]" "\\\\\\&" s)
 460      nil t)))
 461
 462 (defun org-icalendar-fold-string (s)
 463   "Fold string S according to RFC 5545."
 464   (org-element-normalize-string
 465    (mapconcat
 466     (lambda (line)
 467       ;; Limit each line to a maximum of 75 characters.  If it is
 468       ;; longer, fold it by using "\r\n " as a continuation marker.
 469       (let ((len (length line)))
 470         (if (<= len 75) line
 471           (let ((folded-line (substring line 0 75))
 472                 (chunk-start 75)
 473                 chunk-end)
 474             ;; Since continuation marker takes up one character on the
 475             ;; line, real contents must be split at 74 chars.
 476             (while (< (setq chunk-end (+ chunk-start 74)) len)
 477               (setq folded-line
 478                     (concat folded-line "\r\n "
 479                             (substring line chunk-start chunk-end))
 480                     chunk-start chunk-end))
 481             (concat folded-line "\r\n " (substring line chunk-start))))))
 482     (org-split-string s "\n") "\r\n")))
 483
 484
 485 \f
 486 ;;; Filters
 487
 488 (defun org-icalendar-clear-blank-lines (headline _back-end _info)
 489   "Remove blank lines in HEADLINE export.
 490 HEADLINE is a string representing a transcoded headline.
 491 BACK-END and INFO are ignored."
 492   (replace-regexp-in-string "^\\(?:[ \t]*\n\\)+" "" headline))
 493
 494
 495 \f
 496 ;;; Transcode Functions
 497
 498 ;;;; Headline and Inlinetasks
 499
 500 ;; The main function is `org-icalendar-entry', which extracts
 501 ;; information from a headline or an inlinetask (summary,
 502 ;; description...) and then delegates code generation to
 503 ;; `org-icalendar--vtodo' and `org-icalendar--vevent', depending
 504 ;; on the component needed.
 505
 506 ;; Obviously, `org-icalendar--valarm' handles alarms, which can
 507 ;; happen within a VTODO component.
 508
 509 (defun org-icalendar-entry (entry contents info)
 510   "Transcode ENTRY element into iCalendar format.
 511
 512 ENTRY is either a headline or an inlinetask.  CONTENTS is
 513 ignored.  INFO is a plist used as a communication channel.
 514
 515 This function is called on every headline, the section below
 516 it (minus inlinetasks) being its contents.  It tries to create
 517 VEVENT and VTODO components out of scheduled date, deadline date,
 518 plain timestamps, diary sexps.  It also calls itself on every
 519 inlinetask within the section."
 520   (unless (org-element-property :footnote-section-p entry)
 521     (let* ((type (org-element-type entry))
 522            ;; Determine contents really associated to the entry.  For
 523            ;; a headline, limit them to section, if any.  For an
 524            ;; inlinetask, this is every element within the task.
 525            (inside
 526             (if (eq type 'inlinetask)
 527                 (cons 'org-data (cons nil (org-element-contents entry)))
 528               (let ((first (car (org-element-contents entry))))
 529                 (and (eq (org-element-type first) 'section)
 530                      (cons 'org-data
 531                            (cons nil (org-element-contents first))))))))
 532       (concat
 533        (let ((todo-type (org-element-property :todo-type entry))
 534              (uid (or (org-element-property :ID entry) (org-id-new)))
 535              (summary (org-icalendar-cleanup-string
 536                        (or (org-element-property :SUMMARY entry)
 537                            (org-export-data
 538                             (org-element-property :title entry) info))))
 539              (loc (org-icalendar-cleanup-string
 540                    (org-export-get-node-property
 541                     :LOCATION entry
 542                     (org-property-inherit-p "LOCATION"))))
 543              ;; Build description of the entry from associated section
 544              ;; (headline) or contents (inlinetask).
 545              (desc
 546               (org-icalendar-cleanup-string
 547                (or (org-element-property :DESCRIPTION entry)
 548                    (let ((contents (org-export-data inside info)))
 549                      (cond
 550                       ((not (org-string-nw-p contents)) nil)
 551                       ((wholenump org-icalendar-include-body)
 552                        (let ((contents (org-trim contents)))
 553                          (substring
 554                           contents 0 (min (length contents)
 555                                           org-icalendar-include-body))))
 556                       (org-icalendar-include-body (org-trim contents)))))))
 557              (cat (org-icalendar-get-categories entry info))
 558              (tz (org-export-get-node-property
 559                   :TIMEZONE entry
 560                   (org-property-inherit-p "TIMEZONE"))))
 561          (concat
 562           ;; Events: Delegate to `org-icalendar--vevent' to generate
 563           ;; "VEVENT" component from scheduled, deadline, or any
 564           ;; timestamp in the entry.
 565           (let ((deadline (org-element-property :deadline entry)))
 566             (and deadline
 567                  (memq (if todo-type 'event-if-todo 'event-if-not-todo)
 568                        org-icalendar-use-deadline)
 569                  (org-icalendar--vevent
 570                   entry deadline (concat "DL-" uid)
 571                   (concat "DL: " summary) loc desc cat tz)))
 572           (let ((scheduled (org-element-property :scheduled entry)))
 573             (and scheduled
 574                  (memq (if todo-type 'event-if-todo 'event-if-not-todo)
 575                        org-icalendar-use-scheduled)
 576                  (org-icalendar--vevent
 577                   entry scheduled (concat "SC-" uid)
 578                   (concat "S: " summary) loc desc cat tz)))
 579           ;; When collecting plain timestamps from a headline and its
 580           ;; title, skip inlinetasks since collection will happen once
 581           ;; ENTRY is one of them.
 582           (let ((counter 0))
 583             (mapconcat
 584              #'identity
 585              (org-element-map (cons (org-element-property :title entry)
 586                                     (org-element-contents inside))
 587                  'timestamp
 588                (lambda (ts)
 589                  (when (let ((type (org-element-property :type ts)))
 590                          (cl-case (plist-get info :with-timestamps)
 591                            (active (memq type '(active active-range)))
 592                            (inactive (memq type '(inactive inactive-range)))
 593                            ((t) t)))
 594                    (let ((uid (format "TS%d-%s" (cl-incf counter) uid)))
 595                      (org-icalendar--vevent
 596                       entry ts uid summary loc desc cat tz))))
 597                info nil (and (eq type 'headline) 'inlinetask))
 598              ""))
 599           ;; Task: First check if it is appropriate to export it.  If
 600           ;; so, call `org-icalendar--vtodo' to transcode it into
 601           ;; a "VTODO" component.
 602           (when (and todo-type
 603                      (cl-case (plist-get info :icalendar-include-todo)
 604                        (all t)
 605                        (unblocked
 606                         (and (eq type 'headline)
 607                              (not (org-icalendar-blocked-headline-p
 608                                    entry info))))
 609                        ((t) (eq todo-type 'todo))))
 610             (org-icalendar--vtodo entry uid summary loc desc cat tz))
 611           ;; Diary-sexp: Collect every diary-sexp element within ENTRY
 612           ;; and its title, and transcode them.  If ENTRY is
 613           ;; a headline, skip inlinetasks: they will be handled
 614           ;; separately.
 615           (when org-icalendar-include-sexps
 616             (let ((counter 0))
 617               (mapconcat #'identity
 618                          (org-element-map
 619                              (cons (org-element-property :title entry)
 620                                    (org-element-contents inside))
 621                              'diary-sexp
 622                            (lambda (sexp)
 623                              (org-icalendar-transcode-diary-sexp
 624                               (org-element-property :value sexp)
 625                               (format "DS%d-%s" (cl-incf counter) uid)
 626                               summary))
 627                            info nil (and (eq type 'headline) 'inlinetask))
 628                          "")))))
 629        ;; If ENTRY is a headline, call current function on every
 630        ;; inlinetask within it.  In agenda export, this is independent
 631        ;; from the mark (or lack thereof) on the entry.
 632        (when (eq type 'headline)
 633          (mapconcat #'identity
 634                     (org-element-map inside 'inlinetask
 635                       (lambda (task) (org-icalendar-entry task nil info))
 636                       info) ""))
 637        ;; Don't forget components from inner entries.
 638        contents))))
 639
 640 (defun org-icalendar--vevent
 641     (entry timestamp uid summary location description categories timezone)
 642   "Create a VEVENT component.
 643
 644 ENTRY is either a headline or an inlinetask element.  TIMESTAMP
 645 is a timestamp object defining the date-time of the event.  UID
 646 is the unique identifier for the event.  SUMMARY defines a short
 647 summary or subject for the event.  LOCATION defines the intended
 648 venue for the event.  DESCRIPTION provides the complete
 649 description of the event.  CATEGORIES defines the categories the
 650 event belongs to.  TIMEZONE specifies a time zone for this event
 651 only.
 652
 653 Return VEVENT component as a string."
 654   (org-icalendar-fold-string
 655    (if (eq (org-element-property :type timestamp) 'diary)
 656        (org-icalendar-transcode-diary-sexp
 657         (org-element-property :raw-value timestamp) uid summary)
 658      (concat "BEGIN:VEVENT\n"
 659              (org-icalendar-dtstamp) "\n"
 660              "UID:" uid "\n"
 661              (org-icalendar-convert-timestamp timestamp "DTSTART" nil timezone) "\n"
 662              (org-icalendar-convert-timestamp timestamp "DTEND" t timezone) "\n"
 663              ;; RRULE.
 664              (when (org-element-property :repeater-type timestamp)
 665                (format "RRULE:FREQ=%s;INTERVAL=%d\n"
 666                        (cl-case (org-element-property :repeater-unit timestamp)
 667                          (hour "HOURLY") (day "DAILY") (week "WEEKLY")
 668                          (month "MONTHLY") (year "YEARLY"))
 669                        (org-element-property :repeater-value timestamp)))
 670              "SUMMARY:" summary "\n"
 671              (and (org-string-nw-p location) (format "LOCATION:%s\n" location))
 672              (and (org-string-nw-p description)
 673                   (format "DESCRIPTION:%s\n" description))
 674              "CATEGORIES:" categories "\n"
 675              ;; VALARM.
 676              (org-icalendar--valarm entry timestamp summary)
 677              "END:VEVENT"))))
 678
 679 (defun org-icalendar--vtodo
 680   (entry uid summary location description categories timezone)
 681   "Create a VTODO component.
 682
 683 ENTRY is either a headline or an inlinetask element.  UID is the
 684 unique identifier for the task.  SUMMARY defines a short summary
 685 or subject for the task.  LOCATION defines the intended venue for
 686 the task.  DESCRIPTION provides the complete description of the
 687 task.  CATEGORIES defines the categories the task belongs to.
 688 TIMEZONE specifies a time zone for this TODO only.
 689
 690 Return VTODO component as a string."
 691   (let ((start (or (and (memq 'todo-start org-icalendar-use-scheduled)
 692                         (org-element-property :scheduled entry))
 693                    ;; If we can't use a scheduled time for some
 694                    ;; reason, start task now.
 695                    (let ((now (decode-time)))
 696                      (list 'timestamp
 697                            (list :type 'active
 698                                  :minute-start (nth 1 now)
 699                                  :hour-start (nth 2 now)
 700                                  :day-start (nth 3 now)
 701                                  :month-start (nth 4 now)
 702                                  :year-start (nth 5 now)))))))
 703     (org-icalendar-fold-string
 704      (concat "BEGIN:VTODO\n"
 705              "UID:TODO-" uid "\n"
 706              (org-icalendar-dtstamp) "\n"
 707              (org-icalendar-convert-timestamp start "DTSTART" nil timezone) "\n"
 708              (and (memq 'todo-due org-icalendar-use-deadline)
 709                   (org-element-property :deadline entry)
 710                   (concat (org-icalendar-convert-timestamp
 711                            (org-element-property :deadline entry) "DUE" nil timezone)
 712                           "\n"))
 713              "SUMMARY:" summary "\n"
 714              (and (org-string-nw-p location) (format "LOCATION:%s\n" location))
 715              (and (org-string-nw-p description)
 716                   (format "DESCRIPTION:%s\n" description))
 717              "CATEGORIES:" categories "\n"
 718              "SEQUENCE:1\n"
 719              (format "PRIORITY:%d\n"
 720                      (let ((pri (or (org-element-property :priority entry)
 721                                     org-default-priority)))
 722                        (floor (- 9 (* 8. (/ (float (- org-lowest-priority pri))
 723                                             (- org-lowest-priority
 724                                                org-highest-priority)))))))
 725              (format "STATUS:%s\n"
 726                      (if (eq (org-element-property :todo-type entry) 'todo)
 727                          "NEEDS-ACTION"
 728                        "COMPLETED"))
 729              "END:VTODO"))))
 730
 731 (defun org-icalendar--valarm (entry timestamp summary)
 732   "Create a VALARM component.
 733
 734 ENTRY is the calendar entry triggering the alarm.  TIMESTAMP is
 735 the start date-time of the entry.  SUMMARY defines a short
 736 summary or subject for the task.
 737
 738 Return VALARM component as a string, or nil if it isn't allowed."
 739   ;; Create a VALARM entry if the entry is timed.  This is not very
 740   ;; general in that:
 741   ;; (a) only one alarm per entry is defined,
 742   ;; (b) only minutes are allowed for the trigger period ahead of the
 743   ;;     start time,
 744   ;; (c) only a DISPLAY action is defined.                       [ESF]
 745   (let ((alarm-time
 746          (let ((warntime
 747                 (org-element-property :APPT_WARNTIME entry)))
 748            (if warntime (string-to-number warntime) 0))))
 749     (and (or (> alarm-time 0) (> org-icalendar-alarm-time 0))
 750          (org-element-property :hour-start timestamp)
 751          (format "BEGIN:VALARM
 752 ACTION:DISPLAY
 753 DESCRIPTION:%s
 754 TRIGGER:-P0DT0H%dM0S
 755 END:VALARM\n"
 756                  summary
 757                  (if (zerop alarm-time) org-icalendar-alarm-time alarm-time)))))
 758
 759
 760 ;;;; Template
 761
 762 (defun org-icalendar-template (contents info)
 763   "Return complete document string after iCalendar conversion.
 764 CONTENTS is the transcoded contents string.  INFO is a plist used
 765 as a communication channel."
 766   (org-icalendar--vcalendar
 767    ;; Name.
 768    (if (not (plist-get info :input-file)) (buffer-name (buffer-base-buffer))
 769      (file-name-nondirectory
 770       (file-name-sans-extension (plist-get info :input-file))))
 771    ;; Owner.
 772    (if (not (plist-get info :with-author)) ""
 773      (org-export-data (plist-get info :author) info))
 774    ;; Timezone.
 775    (if (org-string-nw-p org-icalendar-timezone) org-icalendar-timezone
 776      (cadr (current-time-zone)))
 777    ;; Description.
 778    (org-export-data (plist-get info :title) info)
 779    contents))
 780
 781 (defun org-icalendar--vcalendar (name owner tz description contents)
 782   "Create a VCALENDAR component.
 783 NAME, OWNER, TZ, DESCRIPTION and CONTENTS are all strings giving,
 784 respectively, the name of the calendar, its owner, the timezone
 785 used, a short description and the other components included."
 786   (concat (format "BEGIN:VCALENDAR
 787 VERSION:2.0
 788 X-WR-CALNAME:%s
 789 PRODID:-//%s//Emacs with Org mode//EN
 790 X-WR-TIMEZONE:%s
 791 X-WR-CALDESC:%s
 792 CALSCALE:GREGORIAN\n"
 793                   (org-icalendar-cleanup-string name)
 794                   (org-icalendar-cleanup-string owner)
 795                   (org-icalendar-cleanup-string tz)
 796                   (org-icalendar-cleanup-string description))
 797           contents
 798           "END:VCALENDAR\n"))
 799
 800
 801 \f
 802 ;;; Interactive Functions
 803
 804 ;;;###autoload
 805 (defun org-icalendar-export-to-ics
 806   (&optional async subtreep visible-only body-only)
 807   "Export current buffer to an iCalendar file.
 808
 809 If narrowing is active in the current buffer, only export its
 810 narrowed part.
 811
 812 If a region is active, export that region.
 813
 814 A non-nil optional argument ASYNC means the process should happen
 815 asynchronously.  The resulting file should be accessible through
 816 the `org-export-stack' interface.
 817
 818 When optional argument SUBTREEP is non-nil, export the sub-tree
 819 at point, extracting information from the headline properties
 820 first.
 821
 822 When optional argument VISIBLE-ONLY is non-nil, don't export
 823 contents of hidden elements.
 824
 825 When optional argument BODY-ONLY is non-nil, only write code
 826 between \"BEGIN:VCALENDAR\" and \"END:VCALENDAR\".
 827
 828 Return ICS file name."
 829   (interactive)
 830   (let ((file (buffer-file-name (buffer-base-buffer))))
 831     (when (and file org-icalendar-store-UID)
 832       (org-icalendar-create-uid file 'warn-user)))
 833   ;; Export part.  Since this back-end is backed up by `ascii', ensure
 834   ;; links will not be collected at the end of sections.
 835   (let ((outfile (org-export-output-file-name ".ics" subtreep)))
 836     (org-export-to-file 'icalendar outfile
 837       async subtreep visible-only body-only
 838       '(:ascii-charset utf-8 :ascii-links-to-notes nil)
 839       (lambda (file)
 840         (run-hook-with-args 'org-icalendar-after-save-hook file) nil))))
 841
 842 ;;;###autoload
 843 (defun org-icalendar-export-agenda-files (&optional async)
 844   "Export all agenda files to iCalendar files.
 845 When optional argument ASYNC is non-nil, export happens in an
 846 external process."
 847   (interactive)
 848   (if async
 849       ;; Asynchronous export is not interactive, so we will not call
 850       ;; `org-check-agenda-file'.  Instead we remove any non-existent
 851       ;; agenda file from the list.
 852       (let ((files (cl-remove-if-not #'file-exists-p (org-agenda-files t))))
 853         (org-export-async-start
 854             (lambda (results)
 855               (dolist (f results) (org-export-add-to-stack f 'icalendar)))
 856           `(let (output-files)
 857              (dolist (file ',files outputfiles)
 858                (with-current-buffer (org-get-agenda-file-buffer file)
 859                  (push (expand-file-name (org-icalendar-export-to-ics))
 860                        output-files))))))
 861     (let ((files (org-agenda-files t)))
 862       (org-agenda-prepare-buffers files)
 863       (unwind-protect
 864           (dolist (file files)
 865             (catch 'nextfile
 866               (org-check-agenda-file file)
 867               (with-current-buffer (org-get-agenda-file-buffer file)
 868                 (org-icalendar-export-to-ics))))
 869         (org-release-buffers org-agenda-new-buffers)))))
 870
 871 ;;;###autoload
 872 (defun org-icalendar-combine-agenda-files (&optional async)
 873   "Combine all agenda files into a single iCalendar file.
 874
 875 A non-nil optional argument ASYNC means the process should happen
 876 asynchronously.  The resulting file should be accessible through
 877 the `org-export-stack' interface.
 878
 879 The file is stored under the name chosen in
 880 `org-icalendar-combined-agenda-file'."
 881   (interactive)
 882   (if async
 883       (let ((files (cl-remove-if-not #'file-exists-p (org-agenda-files t))))
 884         (org-export-async-start
 885             (lambda (_)
 886               (org-export-add-to-stack
 887                (expand-file-name org-icalendar-combined-agenda-file)
 888                'icalendar))
 889           `(apply #'org-icalendar--combine-files ',files)))
 890     (apply #'org-icalendar--combine-files (org-agenda-files t))))
 891
 892 (defun org-icalendar-export-current-agenda (file)
 893   "Export current agenda view to an iCalendar FILE.
 894 This function assumes major mode for current buffer is
 895 `org-agenda-mode'."
 896   (let* ((org-export-use-babel)         ;don't evaluate Babel blocks
 897          (contents
 898           (org-export-string-as
 899            (with-output-to-string
 900              (save-excursion
 901                (let ((p (point-min))
 902                      (seen nil))        ;prevent duplicates
 903                  (while (setq p (next-single-property-change p 'org-hd-marker))
 904                    (let ((m (get-text-property p 'org-hd-marker)))
 905                      (when (and m (not (member m seen)))
 906                        (push m seen)
 907                        (with-current-buffer (marker-buffer m)
 908                          (org-with-wide-buffer
 909                           (goto-char (marker-position m))
 910                           (princ
 911                            (org-element-normalize-string
 912                             (buffer-substring (point)
 913                                               (org-entry-end-position))))))))
 914                    (forward-line)))))
 915            'icalendar t
 916            '(:ascii-charset utf-8 :ascii-links-to-notes nil
 917                             :icalendar-include-todo all))))
 918     (with-temp-file file
 919       (insert
 920        (org-icalendar--vcalendar
 921         org-icalendar-combined-name
 922         user-full-name
 923         (or (org-string-nw-p org-icalendar-timezone) (cadr (current-time-zone)))
 924         org-icalendar-combined-description
 925         contents)))
 926     (run-hook-with-args 'org-icalendar-after-save-hook file)))
 927
 928 (defun org-icalendar--combine-files (&rest files)
 929   "Combine entries from multiple files into an iCalendar file.
 930 FILES is a list of files to build the calendar from."
 931   ;; At the end of the process, all buffers related to FILES are going
 932   ;; to be killed.  Make sure to only kill the ones opened in the
 933   ;; process.
 934   (let ((org-agenda-new-buffers nil))
 935     (unwind-protect
 936         (progn
 937           (with-temp-file org-icalendar-combined-agenda-file
 938             (insert
 939              (org-icalendar--vcalendar
 940               ;; Name.
 941               org-icalendar-combined-name
 942               ;; Owner.
 943               user-full-name
 944               ;; Timezone.
 945               (or (org-string-nw-p org-icalendar-timezone)
 946                   (cadr (current-time-zone)))
 947               ;; Description.
 948               org-icalendar-combined-description
 949               ;; Contents.
 950               (concat
 951                ;; Agenda contents.
 952                (mapconcat
 953                 (lambda (file)
 954                   (catch 'nextfile
 955                     (org-check-agenda-file file)
 956                     (with-current-buffer (org-get-agenda-file-buffer file)
 957                       ;; Create ID if necessary.
 958                       (when org-icalendar-store-UID
 959                         (org-icalendar-create-uid file t))
 960                       (org-export-as
 961                        'icalendar nil nil t
 962                        '(:ascii-charset utf-8 :ascii-links-to-notes nil)))))
 963                 files "")
 964                ;; BBDB anniversaries.
 965                (when (and org-icalendar-include-bbdb-anniversaries
 966                           (require 'org-bbdb nil t))
 967                  (with-output-to-string (org-bbdb-anniv-export-ical)))))))
 968           (run-hook-with-args 'org-icalendar-after-save-hook
 969                               org-icalendar-combined-agenda-file))
 970       (org-release-buffers org-agenda-new-buffers))))
 971
 972
 973 (provide 'ox-icalendar)
 974
 975 ;; Local variables:
 976 ;; generated-autoload-file: "org-loaddefs.el"
 977 ;; End:
 978
 979 ;;; ox-icalendar.el ends here