Order of RRULE components produces different results

[tjmorgan0]

"DTSTART:20220606T110000Z\nRRULE:FREQ=WEEKLY;INTERVAL=1;WKST=SU;BYDAY=TH,FR" only provides the Thursdays as occurrences. When the specification is modified to

"DTSTART:20220606T110000Z\nRRULE:FREQ=WEEKLY;INTERVAL=1;BYDAY=TH,FR;WKST=SU" it works as expected.

Here's the Java code snippet that generates the different results depending on the rruleString.

if (rruleString.length() != 0) { String str = "BEGIN:VCALENDAR\r\n" + "VERSION:2.0\r\n" + "PRODID:-//Microsoft Corporation//Outlook 14.0 MIMEDIR//EN\r\n" + "BEGIN:VEVENT\r\n" + rruleString + "END:VEVENT\r\n" + "END:VCALENDAR\r\n";

        ICalendar ical = Biweekly.parse(str).first();

        VEvent vEvent = ical.getEvents().get(0);
        DateStart dateStart = vEvent.getDateStart();
        OffsetDateTime startDateTime = getOffsetDateTime(dateStart.getValue());

        // Are we before the startDateTime?
        if (startDateTime.isAfter(adjustDateTimeRef)) {
            rtnVal = startDateTime;
        } else {
            Log.d("DateStart = ", dateStart.toString());
            TimeZone timeZone =  TimeZone.getDefault();
            DateIterator it = vEvent.getDateIterator(timeZone);

            // Look for next
            while (it.hasNext()) {
                OffsetDateTime nextDate = getOffsetDateTime(it.next());
                Log.d(TAG, "nextDateTime = " + nextDate);
                if (nextDate.isAfter(adjustDateTimeRef)) {
                    rtnVal = nextDate;
                    break;
                }
            }
        }
    }

[mangstadt]

Unable to reproduce. Both RRULE strings produce the same dates for me.

https://github.com/mangstadt/biweekly/blob/master/src/test/java/biweekly/issues/Issue117.java

[tjmorgan0]

Interesting....

I'll see If I can still create the issue and get back to you.

[tjmorgan0]

I was able to recreate the problem. The key is not including the '\n' between the end of the RRULE and the "END/VEVENT.....

My code has the following::

... "BEGIN:VEVENT\r\n" + rruleString + "END:VEVENT\r\n" + ...

Your test code has this:

... "BEGIN:VEVENT\r\n" + "DTSTART:20220606T110000Z\n" + rruleString + "\r\n" + "END:VEVENT\r\n" + ...

The '\r' appears to be irrelevant. I assuming your using the '\n' as an important part of the parsing algorithm.

I can fix my code. by adding the '\n'

[mangstadt]

The iCalendar specifications require the use of the \r\n newline sequence. However, biweekly will accept \r or \n as well.

Each property must end in \r\n, \r or \n in order for biweekly to parse it.