Jack Kamm <jackk...@gmail.com> writes: > For patch 1 (unscheduled tasks): > > Currently, ox-icalendar does not allow creating an iCalendar task > without a scheduled start date. If an Org TODO is missing a SCHEDULED > timestamp, then ox-icalendar sets today as the scheduled start date for > the exported task. > > Patch 1 changes this by adding a new customization > org-icalendar-todo-force-scheduling. When non-nil, the start date is set > to today (same as the current behavior). When nil, unscheduled Org TODOs > are instead exported without a start date. > > I also propose the default value to be nil. Note, this is > backwards-incompatible with the previous behavior! > > But I think it should be the default anyways, because IMO it is the more > correct and useful behavior. An iCalendar VTODO without a DTSTART > property is valid, and has the same meaning as an Org TODO without a > SCHEDULED timestamp. Also, all the iCalendar programs I have tried > support unscheduled tasks, including Thunderbird, Evolution, Nextcloud, > and Tasks.org.
I agree that omitting DTSTART will make more sense. > For patch 2 (repeating timestamps): > > I add recurrence rule (RRULE) export for repeating SCHEDULED and > DEADLINE timestamps in TODOs, similar to how repeating non-TODO events > are currently handled. > > The main complication here is that iCalendar's RRULE applies to both > DTSTART and DUE properties; by contrast, Org's SCHEDULED and DEADLINE > timestamps may have different repeaters. I am not sure the best way to > handle the case where SCHEDULED and DEADLINE have different repeaters, > so in that case I issue a warning and skip the repeater. In the case of different repeaters, we can use RDATE (https://icalendar.org/iCalendar-RFC-5545/3-8-5-2-recurrence-date-times.html) and generate occurrences manually sufficiently far into future. ("how far" should be a defcustom). However, different repeaters for deadline and schedule are most likely a mistake - we can report it via org-lint and in ox-icalendar, as warning. Another scenario we may need to consider is when schedule has a repeater while deadline does not, and vice versa. The former scenario is probably valid - a VTODO with limited number of occurrences. The latter is likely a mistake we should raise warning about. It is also not clear how to represent moving event deadline in iCalendar. See more inline comments below. > +(defcustom org-icalendar-todo-force-scheduling nil > + "Non-nil means unscheduled tasks are exported as scheduled. > +The current date is used as the scheduled time for such tasks." > + :group 'org-export-icalendar > + :type 'boolean) Please add :package-version and possibly :safe keywords. We may also refer to `org-icalendar-include-todo' in the docstring. > - (org-icalendar-convert-timestamp start "DTSTART" nil timezone) "\n" > + (when start > + (concat (org-icalendar-convert-timestamp > + start "DTSTART" nil timezone) > + "\n")) Side note: here, and in other places, we use "\n" as end of line. Yet, for example https://icalendar.org/iCalendar-RFC-5545/3-8-2-4-date-time-start.html prescribes CRLF (\r\n). Also, see https://orgmode.org/list/87ilgljv6i.fsf@localhost If you are familiar with iCalendar spec, may you look through the ox-icalendar code and check other places where we do not conform to the newline spec? Ideally, we want a set of private functions ensuring proper prescribed format for all the used iCalendar syntax entries. Otherwise, we will keep forgetting about these subtleties. > +(defun org-icalendar--rrule (unit value) > + (format "RRULE:FREQ=%s;INTERVAL=%d\n" \r\n -- Ihor Radchenko // yantar92, Org mode contributor, Learn more about Org mode at <https://orgmode.org/>. Support Org development at <https://liberapay.com/org-mode>, or support my work at <https://liberapay.com/yantar92>
