Adding new features

[jifisherki]

Database query optimization
Added updating recurring event single instance and future instances
Added start week field for recurrence rule
Added return organizer for android module.
Added NonParticipant role
Changed return type to create or update event to Event
Added canAddAttendees and possibleAttendeeProblems for calendar model
Added choice between call in isolate or without it
Added the ability to use the plugin in the background on Android
Added new method for get events from any calendars

[dwenderf]

This looks like a great PR @jifisherki !

I see that you "Added updating recurring event single instance and future instances", however I don't see how to update a single instance or all future instances of an event. I'd love to test this and some of the other features, so if you can help out by letting me know how to do this, that would be very helpful.

I'm also really hoping that the plugin performs better on Android. The existing plugin is quite slow retrieving events on Android relative to iOS. I see you did some query optimization, so I'm looking forward to see how that affects performance.

[jifisherki]

Hi @dwenderf

I see that you "Added updating recurring event single instance and future instances", however I don't see how to update a single instance or all future instances of an event.

For example:

switch (updateDeleteType) {
  case UpdateDeleteEventType.all:
    result = await _calendarPlugin.createOrUpdateEvent(dcEvent);
    break;
  case UpdateDeleteEventType.following:
    result = await _calendarPlugin.updateEventInstance(dcEvent, oldEvent!.start, oldEvent.end, true);
    break;
  case UpdateDeleteEventType.single:
    result = await _calendarPlugin.updateEventInstance(dcEvent, oldEvent!.start, oldEvent.end, false);
    break;
}

As for android. In my opinion, the performance gain is quite high

[dwenderf]

Thanks @jifisherki!

I have one small suggestion for your code. For method updateEventInstance in device_calendar.dart, the parameter should probably be updateFollowingInstances rather than deleteFollowingInstances:

  Future<Result<UnmodifiableListView<Event>>?> updateEventInstance(
    Event? event,
    DateTime? startDate,
    DateTime? endDate,
    bool updateFollowingInstances, {
    bool useIsolate = false,
  }) 

[jifisherki]

@dwenderf

I agree with you

[thomassth]

Please rebase the commit, which should solve the build test error.

And if something changed, please also update the tests.

[thomassth]

Actually, it would be better if you may split the distinct changes into separate PRs. It would be easier for me and others to inspect what changed, and it would be easier to fix if anything goes wrong.