From 7ad4b2df9609fd5893e71836aa2e172023fe2895 Mon Sep 17 00:00:00 2001 From: Detlef Steuer Date: Mon, 16 Jan 2023 23:27:33 +0100 Subject: [PATCH] lisp/ox-icalendar.el: Add customize option `org-icalendar-ttl' * ox-icalendar.el: New option `org-icalendar-ttl' to add en entry for the X-PUBLISHED-TTL option to ox-icalendar. Default value is nil, what means no such entry is exported. If non nil the value must be formated according to https://icalendar.org/iCalendar-RFC-5545/3-8-2-5-duration.html. --- etc/ORG-NEWS | 15 +++++++++++++++ lisp/ox-icalendar.el | 45 ++++++++++++++++++++++++++++++++++++-------- 2 files changed, 52 insertions(+), 8 deletions(-) diff --git a/etc/ORG-NEWS b/etc/ORG-NEWS index c5d9bdf6e..47d808df2 100644 --- a/etc/ORG-NEWS +++ b/etc/ORG-NEWS @@ -13,6 +13,21 @@ Please send Org bug reports to mailto:emacs-orgmode@gnu.org. * Version 9.7 (not released yet) ** New options +*** New custom setting ~org-icalendar-ttl~ for the ~ox-icalendar~ backend + +The option ~org-icalendar-ttl~ allows to advise a subscriber to the +exported ~.ics~ file to reload after the given time interval. + +This is useful i.e. if a calendar server subscribes to your exported +file and that is updated regularly. + +See IETF RFC 5545, Section 3.3.6 Duration and +https://en.wikipedia.org/wiki/ICalendar#Other_component_types for +details. + +Default for ~org-icalendar-ttl~ is nil. In that case the setting will +not be used in the exported ICS file. + *** New options for the "csl" citation export processor's LaTeX output The ~org-cite-csl-latex-label-separator~ and diff --git a/lisp/ox-icalendar.el b/lisp/ox-icalendar.el index 81a77a770..a116ba231 100644 --- a/lisp/ox-icalendar.el +++ b/lisp/ox-icalendar.el @@ -297,6 +297,26 @@ Interesting value are: (const :tag "Universal time" ":%Y%m%dT%H%M%SZ") (string :tag "Explicit format"))) +(defcustom org-icalendar-ttl nil + "The time to life for the exported calendar. +Subscribing clients to the exported ics file can derive the time interval +to read the file again from the server. One example of such a client is +the nextcloud calendar, which respects the setting of +X-PUBLISHED-TTL in an ICS file. Setting org-icalendar-ttl to \"PT1H\" +would advise a server to reload the file every hour. +See https://icalendar.org/iCalendar-RFC-5545/3-8-2-5-duration.html +for a complete description of possible specifications of this option. For +example \"PT1H\" stands for 1 hour, \"PT0H27M34S\" stands for 0 hours, +27 minutes and 34 seconds. Default value is nil, which means no such option +is set in the ICS file." + :group 'org-export-icalendar + :type '(choice + (const :tag "no refresh" nil) + (const :tag "One day" "PT1D") + (const :tag "One week" "PT7D") + (string :tag "Explizit format")) + :package-version '(Org . "9.7")) + (defvar org-icalendar-after-save-hook nil "Hook run after an iCalendar file has been saved. This hook is run with the name of the file as argument. A good @@ -334,7 +354,8 @@ re-read the iCalendar file.") (:icalendar-use-deadline nil nil org-icalendar-use-deadline) (:icalendar-use-scheduled nil nil org-icalendar-use-scheduled) (:icalendar-scheduled-summary-prefix nil nil org-icalendar-scheduled-summary-prefix) - (:icalendar-deadline-summary-prefix nil nil org-icalendar-deadline-summary-prefix)) + (:icalendar-deadline-summary-prefix nil nil org-icalendar-deadline-summary-prefix) + (:icalendar-ttl nil nil org-icalendar-ttl)) :filters-alist '((:filter-headline . org-icalendar-clear-blank-lines)) :menu-entry @@ -872,24 +893,29 @@ as a communication channel." (or (org-string-nw-p org-icalendar-timezone) (format-time-string "%Z")) ;; Description. (org-export-data (plist-get info :title) info) + ;; TTL + (plist-get info :icalendar-ttl) contents)) -(defun org-icalendar--vcalendar (name owner tz description contents) +(defun org-icalendar--vcalendar (name owner tz description ttl contents) "Create a VCALENDAR component. -NAME, OWNER, TZ, DESCRIPTION and CONTENTS are all strings giving, +NAME, OWNER, TZ, DESCRIPTION, TTL and CONTENTS are all strings giving, respectively, the name of the calendar, its owner, the timezone -used, a short description and the other components included." - (concat (format "BEGIN:VCALENDAR +used, a short description, the time-to-live resp. refresh period and +the other components included." + (concat (format (concat "BEGIN:VCALENDAR VERSION:2.0 X-WR-CALNAME:%s PRODID:-//%s//Emacs with Org mode//EN X-WR-TIMEZONE:%s -X-WR-CALDESC:%s -CALSCALE:GREGORIAN\n" +X-WR-CALDESC:%s\n" +(when ttl "X-PUBLISHED-TTL:%s\n") +"CALSCALE:GREGORIAN\n") (org-icalendar-cleanup-string name) (org-icalendar-cleanup-string owner) (org-icalendar-cleanup-string tz) - (org-icalendar-cleanup-string description)) + (org-icalendar-cleanup-string description) + (org-icalendar-cleanup-string ttl)) contents "END:VCALENDAR\n")) @@ -1018,6 +1044,7 @@ This function assumes major mode for current buffer is user-full-name (or (org-string-nw-p org-icalendar-timezone) (format-time-string "%Z")) org-icalendar-combined-description + org-icalendar-ttl contents))) (run-hook-with-args 'org-icalendar-after-save-hook file))) @@ -1042,6 +1069,8 @@ FILES is a list of files to build the calendar from." (format-time-string "%Z")) ;; Description. org-icalendar-combined-description + ;; TTL (Refresh period) + org-icalendar-ttl ;; Contents. (concat ;; Agenda contents. -- 2.39.0