/// <summary>
/// This is used to handle the expansion of the yearly frequency
/// </summary>
/// <param name="dates">The collection in which to put the dates</param>
/// <remarks>The spec is rather vague about how all the rules should interact so I'm making some best
/// guesses here based on the examples in the spec itself although not all combinations are shown.
/// </remarks>
private void ExpandYearly(RecurDateTimeCollection dates)
{
RecurDateTimeCollection rdtcMonth = null, rdtcMoDay = null, rdtcWeek = null, rdtcYrDay = null,
rdtcDay = null;
bool isExpanded = false;
// We'll expand each rule individually and combine the results before applying the time expansions.
// The application of the BYMONTHDAY and BYDAY rules varies based on whatever other rule parts are
// present as well.
if(byMonth.Count != 0)
{
// Expand by month
isExpanded = true;
rdtcMonth = new RecurDateTimeCollection(dates);
freqRules.ByMonth(this, rdtcMonth);
// If BYMONTHDAY and BYDAY are both specified, we need to expand by month day and then filter by
// day. If we expand by day alone, note that we do so only in the months specified in the
// BYMONTH rule.
if(byMonthDay.Count != 0 && byDay.Count != 0)
{
Expand.ByMonthDay(this, rdtcMonth);
Filter.ByDay(this, rdtcMonth);
}
else
if(Expand.ByMonthDay(this, rdtcMonth) != 0)
Expand.ByDayInMonths(this, rdtcMonth);
}
else
{
if(byMonthDay.Count != 0)
{
// Expand by month day if specified without any by month rule part
isExpanded = true;
rdtcMoDay = new RecurDateTimeCollection(dates);
freqRules.ByMonthDay(this, rdtcMoDay);
}
// As long as by week number isn't specified either, we'll expand the by day rule here too
if(byWeekNo.Count == 0)
{
isExpanded = true;
rdtcDay = new RecurDateTimeCollection(dates);
freqRules.ByDay(this, rdtcDay);
}
}
if(byWeekNo.Count != 0)
{
// Expand by week number
isExpanded = true;
rdtcWeek = new RecurDateTimeCollection(dates);
freqRules.ByWeekNo(this, rdtcWeek);
// Expand by days of the week in those weeks
Expand.ByDayInWeeks(this, rdtcWeek);
}
if(byYearDay.Count != 0)
{
// Expand by year day
isExpanded = true;
rdtcYrDay = new RecurDateTimeCollection(dates);
freqRules.ByYearDay(this, rdtcYrDay);
}
// Combine the various expansions. If nothing was done, leave the original date in the collection.
if(isExpanded)
{
dates.Clear();
if(rdtcMonth != null && rdtcMonth.Count != 0)
dates.AddRange(rdtcMonth);
if(rdtcMoDay != null && rdtcMoDay.Count != 0)
dates.AddRange(rdtcMoDay);
if(rdtcWeek != null && rdtcWeek.Count != 0)
dates.AddRange(rdtcWeek);
if(rdtcYrDay != null && rdtcYrDay.Count != 0)
dates.AddRange(rdtcYrDay);
if(rdtcDay != null && rdtcDay.Count != 0)
dates.AddRange(rdtcDay);
}
// In any case, the time parts are easy. They always expand the instances if there's anything there.
if(dates.Count != 0)
{
Expand.ByHour(this, dates);
Expand.ByMinute(this, dates);
Expand.BySecond(this, dates);
}
}