EventKit Alarms are how we configure notifications and alerts that will be triggered to remind the user about calendar events or reminders.

Like in Bite #96, we'll use Timepiece (Bite #3) to help us compose dates. We'll create an event for when our cookies will be done baking. The event will start in 12 minutes, and we'll add a new EKAlarm to it that triggers 5 seconds before the event. Alarms can be created with at absolute or relative times.

let e = EKEvent(eventStore: eventStore)

e.startDate = NSDate() + 12.minutes
e.endDate = e.startDate + 30.seconds
e.calendar = eventStore.defaultCalendarForNewEvents
e.title = "Cookies are Done! 🍪"

e.addAlarm(EKAlarm(relativeOffset: -5.0))

try eventStore.saveEvent(e, span: .ThisEvent)

Interestingly, OS X is actually ahead of iOS here. EKAlarm on OS X **has more **properties for configuring a sound to play, an email address to notify and more.

Now when we get to Disneyland, the alarm will remind us to head over to . (Just an example, in real life we'd never need the reminder).

Things get more fun when adding alarms to reminders. Let's finish by adding an alarm to a new reminder that triggers when the user arrives somewhere:

let reminder = EKReminder(eventStore: eventStore)

reminder.title = "Ride Star Tours“
reminder.calendar = eventStore.defaultCalendarForNewReminders()

let location = EKStructuredLocation(title: "Disneyland")
location.geoLocation = CLLocation(
  latitude: 33.8120918, longitude: -117.9189742
)

let alarm = EKAlarm()

alarm.structuredLocation = location
alarm.proximity = .Enter

reminder.addAlarm(alarm)

try eventStore.saveReminder(reminder, commit: true)

EventKit is how we access and interact with a user's calendars and events. It has APIs to manage events, reminders, alarms and even participants. Today we'll take a look at the basics. Let's get started.

Authorization

Before doing anything fun, we'll need to check the current authorization status, then request permission if needed.

switch EKEventStore.authorizationStatusForEntityType(.Event) {
case .Authorized:
  fetchCalendars()
case .NotDetermined:
  requestAccessToCalendars()
case .Restricted, .Denied:
  showAccessDeniedAlert()
}

To do anything interesting, we'll need an EKEventStore.

let eventStore = EKEventStore()

Apple suggests we keep a long-lived instance around, so we'll keep ours in a property. Now we can write our function:

eventStore.requestAccessToEntityType(.Event) { (granted, error) in
  guard granted else { return }
  self.fetchCalendars()
}

Fetching Calendars & Events

let calendars = eventStore.calendarsForEntityType(.Event)

Lastly, we'll use the handy function to put new events where the user expects:

We'll use Timepiece (Bite #3) to help us compose dates. Then we'll create a predicate to look for events in the last week, across all the user's calendars.

Adding an Event

let event = EKEvent(eventStore: eventStore)

event.title = "Drop off Carbonite Shipment"
event.startDate = "3031-02-15".dateFromFormat("yyyy-MM-dd")
event.calendar = eventStore.defaultCalendarForNewEvents

try eventStore.saveEvent(event, span: .ThisEvent)