/// <summary>
/// CanProduceOccurrences,
/// This will return true if this event is capable of generating occurrences, otherwise false.
/// For performance reasons, it is a good idea to include a limit on the number of years that are
/// searched for occurrences. (For example, 110 years).
///
/// If no limit is supplied, and the event has no end date, then this function can
/// (in the worst-case scenario) search for an occurrence until DateTime.MaxDate which is the year 9999,
/// which can take a lot of processing time.
/// </summary>
public bool CanProduceOccurrences(int?withinYears)
{
if (HasBrokenZeroOccurrenceConfiguration())
{
return(false);
}
DateRange eventLimits = GetEventLimitsAsDateRange();
int daysInRange = eventLimits.GetNumberOfDaysInRange();
int maximumDaysWithoutOccurrence = RepeatInterval;
switch (FrequencyTypeOptions)
{
case FrequencyTypeEnum.Daily:
break;
case FrequencyTypeEnum.Weekly:
case FrequencyTypeEnum.EveryWeekDay:
case FrequencyTypeEnum.EveryMonWedFri:
case FrequencyTypeEnum.EveryTuTh:
maximumDaysWithoutOccurrence *= 7;
break;
case FrequencyTypeEnum.Monthly:
maximumDaysWithoutOccurrence *= 31;
break;
case FrequencyTypeEnum.Quarterly:
maximumDaysWithoutOccurrence *= 96;
break;
case FrequencyTypeEnum.Yearly:
// Leap years have 366 days.
maximumDaysWithoutOccurrence *= 366;
break;
}
if (daysInRange > maximumDaysWithoutOccurrence)
{
return(true);
}
Schedule schedule = new Schedule(this);
DateTime?occurrence;
if (withinYears != null)
{
occurrence = schedule.NextOccurrence(eventLimits.StartDateTime,
new DateRange(eventLimits.StartDateTime, eventLimits.StartDateTime.SafeAddYears((int)withinYears)));
}
else
{
occurrence = schedule.NextOccurrence(eventLimits.StartDateTime,
new DateRange(eventLimits.StartDateTime, eventLimits.EndDateTime));
}
if (occurrence != null)
{
return(true);
}
return(false);
}
