/**
* Build iCalendar-compliant recurrence rule
*
* @param recurrence
* @param recurrenceEnd
* @return rrule
*/
public static String getRecurrenceRule(final String recurrence, final Date recurrenceEnd) {
final TimeZone tz =
TimeZoneRegistryFactory.getInstance()
.createRegistry()
.getTimeZone(java.util.Calendar.getInstance().getTimeZone().getID());
if (recurrence != null) { // recurrence available
// create recurrence rule
final StringBuilder sb = new StringBuilder();
sb.append("FREQ=");
if (recurrence.equals(CalendarEntry.WORKDAILY)) {
// build rule for monday to friday
sb.append(CalendarEntry.DAILY);
sb.append(";");
sb.append("BYDAY=MO,TU,WE,TH,FR");
} else if (recurrence.equals(CalendarEntry.BIWEEKLY)) {
// build rule for biweekly
sb.append(CalendarEntry.WEEKLY);
sb.append(";");
sb.append("INTERVAL=2");
} else {
// normal supported recurrence
sb.append(recurrence);
}
if (recurrenceEnd != null) {
final DateTime recurEndDT = new DateTime(recurrenceEnd.getTime());
recurEndDT.setTimeZone(tz);
sb.append(";");
sb.append(CalendarEntry.UNTIL);
sb.append("=");
sb.append(recurEndDT.toString());
}
try {
final Recur recur = new Recur(sb.toString());
final RRule rrule = new RRule(recur);
return rrule.getValue();
} catch (final ParseException e) {
log.error("cannot create recurrence rule: " + recurrence.toString(), e);
}
}
return null;
}
/**
* Returns the latest applicable onset of this observance for the specified date.
*
* @param date the latest date that an observance onset may occur
* @return the latest applicable observance date or null if there is no applicable observance
* onset for the specified date
*/
public final Date getLatestOnset(final Date date) {
if (initialOnset == null) {
try {
initialOnset =
applyOffsetFrom(calculateOnset(((DtStart) getProperty(Property.DTSTART)).getDate()));
} catch (ParseException e) {
Log log = LogFactory.getLog(Observance.class);
log.error("Unexpected error calculating initial onset", e);
// XXX: is this correct?
return null;
}
}
// observance not applicable if date is before the effective date of this observance..
if (date.before(initialOnset)) {
return null;
}
if ((onsetsMillisec != null) && (onsetLimit == null || date.before(onsetLimit))) {
return getCachedOnset(date);
}
Date onset = initialOnset;
Date initialOnsetUTC;
// get first onset without adding TZFROM as this may lead to a day boundary
// change which would be incompatible with BYDAY RRULES
// we will have to add the offset to all cacheable onsets
try {
initialOnsetUTC = calculateOnset(((DtStart) getProperty(Property.DTSTART)).getDate());
} catch (ParseException e) {
Log log = LogFactory.getLog(Observance.class);
log.error("Unexpected error calculating initial onset", e);
// XXX: is this correct?
return null;
}
// collect all onsets for the purposes of caching..
final DateList cacheableOnsets = new DateList();
cacheableOnsets.setUtc(true);
cacheableOnsets.add(initialOnset);
// check rdates for latest applicable onset..
final PropertyList rdates = getProperties(Property.RDATE);
for (final Iterator i = rdates.iterator(); i.hasNext(); ) {
final RDate rdate = (RDate) i.next();
for (final Iterator j = rdate.getDates().iterator(); j.hasNext(); ) {
try {
final DateTime rdateOnset = applyOffsetFrom(calculateOnset((Date) j.next()));
if (!rdateOnset.after(date) && rdateOnset.after(onset)) {
onset = rdateOnset;
}
/*
* else if (rdateOnset.after(date) && rdateOnset.after(onset) && (nextOnset == null ||
* rdateOnset.before(nextOnset))) { nextOnset = rdateOnset; }
*/
cacheableOnsets.add(rdateOnset);
} catch (ParseException e) {
Log log = LogFactory.getLog(Observance.class);
log.error("Unexpected error calculating onset", e);
}
}
}
// check recurrence rules for latest applicable onset..
final PropertyList rrules = getProperties(Property.RRULE);
for (final Iterator i = rrules.iterator(); i.hasNext(); ) {
final RRule rrule = (RRule) i.next();
// include future onsets to determine onset period..
final Calendar cal = Dates.getCalendarInstance(date);
cal.setTime(date);
cal.add(Calendar.YEAR, 10);
onsetLimit = Dates.getInstance(cal.getTime(), Value.DATE_TIME);
final DateList recurrenceDates =
rrule.getRecur().getDates(initialOnsetUTC, onsetLimit, Value.DATE_TIME);
for (final Iterator j = recurrenceDates.iterator(); j.hasNext(); ) {
final DateTime rruleOnset = applyOffsetFrom((DateTime) j.next());
if (!rruleOnset.after(date) && rruleOnset.after(onset)) {
onset = rruleOnset;
}
/*
* else if (rruleOnset.after(date) && rruleOnset.after(onset) && (nextOnset == null ||
* rruleOnset.before(nextOnset))) { nextOnset = rruleOnset; }
*/
cacheableOnsets.add(rruleOnset);
}
}
// cache onsets..
Collections.sort(cacheableOnsets);
DateTime cacheableOnset = null;
this.onsetsMillisec = new long[cacheableOnsets.size()];
this.onsetsDates = new DateTime[onsetsMillisec.length];
for (int i = 0; i < onsetsMillisec.length; i++) {
cacheableOnset = (DateTime) cacheableOnsets.get(i);
onsetsMillisec[i] = cacheableOnset.getTime();
onsetsDates[i] = cacheableOnset;
}
return onset;
}