teno_rrule

Description:

teno rrule

Dart Recurrence Rule implements RFC5545 (iCalendar) #
This library is designed to support what are defined in RFC5545 - Recurrence Rule.
What is to choose between this library (teno_rrule) vs rrule #



If you are looking for
Ideal choice




Stable with many usages
rrule


Features like WKST, Timezone, Exdates, ...
teno-rrule


Both above
You will made



Getting started #
This library utilizes timezone to support timezone-based DateTime (TZDateTime),
so make sure you follow the instruction their for initializing the location database. For short:
import 'package:timezone/data/latest_10y.dart';
...
initializeTimeZones();
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By default, the library will using the standard alone version of the library.
Add this library to your pubspec.yaml
dart pub add teno-rrule
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And you are good to go!
Usage #
Create Recurrence Rule instance from code:
final rrule = RecurrenceRule(
frequency: Frequency.weekly,
startDate: DateTime(1997, 9, 2, 9, 0, 0),
byWeekDays: {WeekDay.monday, WeekDay.wednesday, WeekDay.friday});
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Get its recurrence by
final instances = rrule.between(DateTime(1997, 9, 2, 9), DateTime(1997, 10, 2, 9));
// gets: 1997-09-03 09:00:00.000, 1997-09-05 09:00:00.000, ... 1997-10-01 09:00:00.000
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end range is exclusive.
Parse from string
final rruleString = 'DTSTART;TZID=America/New_York:19970902T090000\n'
'RRULE:FREQ=DAILY;INTERVAL=2';
final rrule = RecurrenceRule.from(rruleString);
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You need to initialize the Location database before parsing from string with TZID, otherwise it will throw exception!

To use with timezone, you first need to initialize location database at getting start section
final rrule = RecurrenceRule(
frequency: Frequency.daily,
count: 10,
isLocal: false,
startDate: TZDateTime(getLocation('America/New_York'), 1997, 9, 2, 9));
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By default, isLocal = true, means it won't care about the timezone in startDate and treats everything as local time.
To use with timezone, please set this flag to false.
To specify the first day of week
final rrule = RecurrenceRule(
frequency: Frequency.weekly,
count: 10,
weekStart: DateTime.sunday,
byWeekDays: {WeekDay.tuesday, WeekDay.thursday},
startDate: DateTime(1997, 9, 2, 9));
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by default, WKST will take the value of firstDayOfWeek from teno_datetime, so you can:

Override the WKST by setting value to property weekStart
Override globally by setting value to firstDayOfWeek, for ex:

firstDayOfWeek = DateTime.saturday;
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To select the n occurrence of day
final rrule = RecurrenceRule(
frequency: Frequency.monthly,
interval: 2,
count: 10,
byWeekDays: {
WeekDay.sunday.withOccurrence(1), // or WeekDay(DateTime.sunday, 1)
WeekDay.sunday.withOccurrence(-1) // or WeekDay(DateTime.sunday, -1)
},
isLocal: false,
startDate:
TZDateTime(getLocation('America/New_York'), 1997, 09, 07, 9));
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To exclude a date (EXDATE rule)
final rrule = RecurrenceRule(
frequency: Frequency.monthly,
byMonthDays: {13},
byWeekDays: {WeekDay.friday},
isLocal: false,
startDate:
TZDateTime(getLocation('America/New_York'), 1997, 09, 02, 9),
excludedDates: {
TZDateTime(getLocation('America/New_York'), 1997, 09, 02, 9)
});
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copyWith
final anotherRRule = rrule.copyWith(interval: 5, count: 5);
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Additional information #
This library has been tested with all examples from RFC5545 - section 3.8.5.3. You can have a look at:
test/conversions_test.dart
test/query_test.dart
You can refer to the current progress at: TODO.md
If you found a bug, issue, or have a request. #
Please submit an issue at https://github.com/hnvcam/teno_rrule/issues. And give me sometime to take a look on it.
I won't promise to take the action soon, but I will reply you my plan.

If you find this library is useful #