The document discusses the Event Kit framework for interacting with the Calendar and Reminders apps in iOS. It provides code examples for requesting access to calendars, fetching calendar and event data using predicates, creating, modifying and deleting events and reminders. It also covers observing external changes to the calendar database and using interfaces like EKEventViewController for displaying event data.

1. Event Kit
Framework
Calendar. Reminder.

2. ● Calendar.app
● Reminders.app
Event Kit Architecture

3. Requesting Permission to Access Calendars
Init EKEventStore:
eventStore = EKEventStore()
Check authorization status:
let status:EKAuthorizationStatus = EKEventStore.authorizationStatusForEntityType(EKEntityTypeEvent)
switch (status) {
case .Authorized: accessGrantedForCalendar()
break
case .NotDetermined: requestCalendarAccess()
break
case .Denied, .Restricted:
break
}
Request Calendar access:
eventStore?.requestAccessToEntityType(EKEntityTypeEvent, completion: {
[weak self] (granted:Bool, error:NSError!) -> Void in
dispatch_async(dispatch_get_main_queue()) {
self!.accessGrantedForCalendar()
}
})

4. func fetchCallendarGroups(eventStore:EKEventStore) {
for source in eventStore.sources() as [EKSource] {
println("Group: title = (source.title)" +
" type = (source.sourceType.value)")
}
}
/* Log
Group: title = Default type = 0
Group: title = Other type = 5
Group: title = Gmail type = 2
Group: title = CalDAV type = 2
Group: title = iCloud type = 2
*/
Event. Fetch Calendar Groups

5. func fetchAllCallendars() {
Event. Fetch All Calendars
let calendars = eventStore.calendarsForEntityType(EKEntityTypeEvent) as [EKCalendar]
for calendar in calendars {
println("Calendar: title = (calendar.title)" +
" type = (calendar.type.value)" +
" allows modifications = (calendar.allowsContentModifications)")
}
}
/* Log
Calendar: title = Work type = 1 allows modifications = true
Calendar: title = Home type = 1 allows modifications = true
Calendar: title = Birthdays type = 4 allows modifications = false
Calendar: title = a.voityuk@gmail.com type = 1 allows modifications = true
Calendar: title = Calendar type = 1 allows modifications = false
*/

6. Event. Fetch Events Using Predicates
func fetchEvents(calendar: EKCalendar) {
/* The event starts from today, right now */
let startDate = NSDate()
/* The end date will be 7 day from now */
let endDate = startDate.dateByAddingTimeInterval(24 * 60 * 60 * 7)
/* Create the predicate that we can later pass to the event store in order to fetch the events */
let searchPredicate = eventStore.predicateForEventsWithStartDate(startDate, endDate: endDate, calendars: nil)
/* Fetch all the events that fall between the starting and the ending dates */
let events = eventStore.eventsMatchingPredicate(searchPredicate) as [EKEvent]
for event in events {
println("Event: title = (event.title)")
}
}
/* Log
Event: title = Alexander Voityuk’s 28. Birthday
Event: title = Maxim Matyash’s 30. Birthday
*/

7. func createEventWithTitle(title: String, startDate: NSDate, endDate: NSDate, inCalendar: EKCalendar, inEventStore: EKEventStore) -> Bool {
/* Create an event */
var event = EKEvent(eventStore: inEventStore)
event.calendar = inCalendar
/* Set the properties of the event such as its title, start date/time, end date/time, etc. */
event.title = title
event.startDate = startDate
event.endDate = endDate
/* Finally, save the event into the calendar */
var error:NSError?
let result = inEventStore.saveEvent(event,
span: EKSpanThisEvent,
error: &error)
return result
}
Event. Create Event

8. func removeEvent(event: EKEvent, store: EKEventStore, calendar: EKCalendar) -> Bool{
var result = false
var error:NSError?
/* remove the event from the calendar */
if store.removeEvent(event,
span: EKSpanThisEvent,
commit: true,
error: &error) {
result = true
} else if let theError = error {
println("Failed to remove (event) with error = (theError)")
}
return result
}
Event. Remove Event

9. func addAlarmToCalendarWithStore(title: String, startDate: NSDate, endDate: NSDate, store: EKEventStore, calendar: EKCalendar) {
/* Assign the required properties, especially the target calendar */
let eventWithAlarm = EKEvent(eventStore: store)
eventWithAlarm.title = title
eventWithAlarm.calendar = calendar
eventWithAlarm.startDate = startDate
eventWithAlarm.endDate = endDate
/* The alarm goes off 2 seconds before the event happens */
let alarm = EKAlarm(relativeOffset: -2.0)
eventWithAlarm.addAlarm(alarm)
var error:NSError?
if store.saveEvent(eventWithAlarm, span: EKSpanThisEvent, error: &error) {
println("Saved an event that fires 60 seconds from now.")
} else if let theError = error {
println("Failed to save the event. Error = (theError)")
}
}
Event. Add Alarm

10. func addRecurringRuleToEvent(event: EKEvent) {
/* The end date of the recurring rule is one year from now */
let oneYear:NSTimeInterval = 365 * 24 * 60 * 60;
let oneYearFromNow = startDate.dateByAddingTimeInterval(oneYear)
/* Create an Event Kit date from this date */
let recurringEnd = EKRecurrenceEnd.recurrenceEndWithEndDate(oneYearFromNow) as EKRecurrenceEnd
/* And the recurring rule. This event happens every
month (EKRecurrenceFrequencyMonthly), once a month (interval:1)
and the recurring rule ends a year from now (end:RecurringEnd) */
let recurringRule = EKRecurrenceRule(
recurrenceWithFrequency: EKRecurrenceFrequencyMonthly,
interval: 1,
end: recurringEnd)
/* Set the recurring rule for the event */
event.recurrenceRules = [recurringRule]
}
Event. Add Recurring Rule

11. func fetchAllCallendars() {
Reminder. Fetch All Calendars
let calendars = eventStore.calendarsForEntityType(EKEntityTypeReminder) as [EKCalendar]
for calendar in calendars {
println("Calendar: title = (calendar.title)" +
" type = (calendar.type.value)" +
" allows modifications = (calendar.allowsContentModifications)")
}
}
/* Log
Calendar: title = Reminders type = 1 allows modifications = true
*/

12. Reminder. Fetch Reminders Using Predicates
func fetchReminders(calendar: EKCalendar) -> NSMutableArray {
/* The event starts from today, right now */
let startDate = NSDate()
/* The end date will 7day from now */
let endDate = startDate.dateByAddingTimeInterval(24 * 60 * 60 * 7)
/* Create the predicate that we can later pass to the event store in order to fetch the events */
let searchPredicate = eventStore.predicateForIncompleteRemindersWithDueDateStarting(startDate, ending: endDate, calendars: nil)
/* Fetch all the reminder that fall between the starting and the ending dates */
eventStore.fetchRemindersMatchingPredicate(searchPredicate, completion: {
(reminders) -> Void in
for reminder in reminders {
println("Event: title = (reminder.title)")
}
})
}
/* Log
Reminder: title = My Reminder 1
Reminder: title = My Reminder 2
*/

13. func createReminderWithTitle(title: String, inCalendar: EKCalendar, inEventStore: EKEventStore, notes: String) -> Bool {
/* Create an reminder */
var reminder = EKReminder(eventStore: inEventStore)
reminder.calendar = inCalendar
/* Set the properties of the event such as its title, notes. */
reminder.title = title
reminder.notes = notes
/* Finally, save the reminder into the calendar */
var error:NSError?
let result = inEventStore.saveReminder(reminder,
commit: true,
error: &error)
if result == false {
if let theError = error{
println("An error occurred (theError)")
}
}
return result
}
Reminder. Create Reminder

14. func removeReminder(reminder: EKReminder, store: EKEventStore, calendar: EKCalendar) -> Bool{
var result = false
var error:NSError?
/* remove the reminder from the calendar */
if store.removeReminder(reminder,
commit: true,
error: &error) {
result = true
} else if let theError = error{
println("Failed to remove (reminder) with error = (theError)")
}
return result
}
Reminder. Remove Reminder

15. /* Add observer */
NSNotificationCenter.defaultCenter().addObserver(
self,
selector: "eventStoreDidChanged:",
name: EKEventStoreChangedNotification,
object: nil)
func eventStoreDidChanged(notification:NSNotification) {
// TODO
}
Observing External Changes
to the Calendar Database

16. Add delegate EKEventViewDelegate to current ViewController
func displayExistingEvent(event : EKEvent, store : EKEventStore) {
let controller:EKEventViewController = EKEventViewController()
controller.event = event;
controller.allowsEditing = true;
self.presentViewController(UINavigationController(rootViewController: controller), animated: true, completion: nil)
}
// MARK: - EKEventViewDelegate
func eventViewController(controller: EKEventViewController!, didCompleteWithAction action: EKEventViewAction) {
self.dismissViewControllerAnimated(true, completion: {
() -> Void in
// TODO
})
}
Interfaces for Events. Displaying Event Data

17. Add delegate EKEventEditViewDelegate to current ViewController
func editExistingEvent(event : EKEvent, store : EKEventStore) {
let controller:EKEventEditViewController = EKEventEditViewController()
controller.event = event
controller.eventStore = store
controller.editViewDelegate = self
self.presentViewController(controller, animated: true, completion: nil)
}
// MARK: - EKEventEditViewDelegate
func eventEditViewController(controller: EKEventEditViewController!, didCompleteWithAction action: EKEventEditViewAction) {
self.dismissViewControllerAnimated(true, completion: {
() -> Void in
// TODO
})
}
func eventEditViewControllerDefaultCalendarForNewEvents(controller: EKEventEditViewController!) -> EKCalendar! {
return defaultCalendar
}
Interfaces for Events. Modifying Event Data

18. End
Calendar and Reminders Programming Guide:
https://developer.apple.com/library/ios/documentation/DataManagement/Conceptual/EventKitProgGuide/Introduction/Introduction.html
Apple Sample Project “SimpleEKDemo”:
https://developer.apple.com/library/ios/samplecode/SimpleEKDemo/Introduction/Intro.html#//apple_ref/doc/uid/DTS40010160