iCalendarRecurrence

Overview

Generates and returns an array of Date objects created by the provided SchedulingData object's recurrence properties. Follows the iCalendar specification, located at http://tools.ietf.org/html/rfc5545.

Creating the iCalendarRecurrence Component

Class is entirely static. Therefore there is no need to create an instance to use it. Simply call the generateRecurrenceDates() method to use the class.

Using the iCalendarRecurrence Component

Call the generateRecurrenceDates() method and pass the SchedulingData object to use and a start date. The method will return an array of the generated recurring dates.

The passed start date parameter is optional and indicates when to start generating recurring dates rather than the "dtStart" property of the provided SchedulingData object. The optional start date will not be returned in the results array.

Custom start dates are useful to get portions of an infinite recurrence set.

Infinite Recurrence

If the SchedulingData object being used to generate recurrence does not specify an "until" or "count" properties it could create an infinite number of recurring dates. To prevent this from happening, the "defaultUntil" property can be set to automatically apply a date to short circuit if the passed SchedulingData object does not explicitly designate a short-circuit date.

In the event that none of the above properties are set, the class will automatically apply a short circuit 2 years after the start date for the recurrence.

Recurrence Frequency Order

Taken from the iCalendar specification:

 +----------+--------+--------+-------+-------+------+-------+------+
 |          |SECONDLY|MINUTELY|HOURLY |DAILY  |WEEKLY|MONTHLY|YEARLY|
 +----------+--------+--------+-------+-------+------+-------+------+
 |BYMONTH   |Limit   |Limit   |Limit  |Limit  |Limit |Limit  |Expand|
 +----------+--------+--------+-------+-------+------+-------+------+
 |BYWEEKNO  |N/A     |N/A     |N/A    |N/A    |N/A   |N/A    |Expand|
 +----------+--------+--------+-------+-------+------+-------+------+
 |BYYEARDAY |Limit   |Limit   |Limit  |N/A    |N/A   |N/A    |Expand|
 +----------+--------+--------+-------+-------+------+-------+------+
 |BYMONTHDAY|Limit   |Limit   |Limit  |Limit  |N/A   |Expand |Expand|
 +----------+--------+--------+-------+-------+------+-------+------+
 |BYDAY     |Limit   |Limit   |Limit  |Limit  |Expand|Note 1 |Note 2|
 +----------+--------+--------+-------+-------+------+-------+------+
 |BYHOUR    |Limit   |Limit   |Limit  |Expand |Expand|Expand |Expand|
 +----------+--------+--------+-------+-------+------+-------+------+
 |BYMINUTE  |Limit   |Limit   |Expand |Expand |Expand|Expand |Expand|
 +----------+--------+--------+-------+-------+------+-------+------+
 |BYSECOND  |Limit   |Expand  |Expand |Expand |Expand|Expand |Expand|
 +----------+--------+--------+-------+-------+------+-------+------+
 |BYSETPOS  |Limit   |Limit   |Limit  |Limit  |Limit |Limit  |Limit |
 +----------+--------+--------+-------+-------+------+-------+------+

Note 1:  Limit if BYMONTHDAY is present; otherwise, special expand
	 or MONTHLY.

Note 2:  Limit if BYYEARDAY or BYMONTHDAY is present; otherwise,
	 special expand for WEEKLY if BYWEEKNO present; otherwise, special expand 
	 for MONTHLY if BYMONTH present; otherwise, special expand for YEARLY.

SchedulingData

See the ASDocs for the ardisia.scheduling.dataTypes.SchedulingData class for the pertinent recurrence properties.

Example

See the iCalendarRecurrence demo application for example code.

Back To Top