Classes/RootViewController.m
/* |
Copyright (C) 2015 Apple Inc. All Rights Reserved. |
See LICENSE.txt for this sample’s licensing information |
Abstract: |
Table view controller that displays events occuring within the next 24 hours. Prompts a user for access to their Calendar, then updates its UI according to their response. |
*/ |
#import "RootViewController.h" |
@interface RootViewController () <EKEventEditViewDelegate> |
// EKEventStore instance associated with the current Calendar application |
@property (nonatomic, strong) EKEventStore *eventStore; |
// Default calendar associated with the above event store |
@property (nonatomic, strong) EKCalendar *defaultCalendar; |
// Array of all events happening within the next 24 hours |
@property (nonatomic, strong) NSMutableArray *eventsList; |
// Used to add events to Calendar |
@property (weak, nonatomic) IBOutlet UIBarButtonItem *addButton; |
@end |
@implementation RootViewController |
#pragma mark - |
#pragma mark View lifecycle |
- (void)viewDidLoad |
{ |
[super viewDidLoad]; |
// Initialize the event store |
self.eventStore = [[EKEventStore alloc] init]; |
// Initialize the events list |
self.eventsList = [[NSMutableArray alloc] initWithCapacity:0]; |
// The Add button is initially disabled |
self.addButton.enabled = NO; |
} |
-(void)viewDidAppear:(BOOL)animated |
{ |
[super viewDidAppear:animated]; |
// Check whether we are authorized to access Calendar |
[self checkEventStoreAccessForCalendar]; |
} |
// This method is called when the user selects an event in the table view. It configures the destination |
// event view controller with this event. |
- (void)prepareForSegue:(UIStoryboardSegue *)segue sender:(id)sender |
{ |
if ([segue.identifier isEqualToString:@"showEventViewController"]) |
{ |
// Configure the destination event view controller |
EKEventViewController* eventViewController = (EKEventViewController *)segue.destinationViewController; |
// Fetch the index path associated with the selected event |
NSIndexPath *indexPath = (self.tableView).indexPathForSelectedRow; |
// Set the view controller to display the selected event |
eventViewController.event = (self.eventsList)[indexPath.row]; |
// Allow event editing |
eventViewController.allowsEditing = YES; |
} |
} |
#pragma mark - |
#pragma mark Table View |
- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section |
{ |
return self.eventsList.count; |
} |
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath |
{ |
UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:@"eventCell" forIndexPath:indexPath]; |
// Get the event at the row selected and display its title |
cell.textLabel.text = [(self.eventsList)[indexPath.row] title]; |
return cell; |
} |
#pragma mark - |
#pragma mark Access Calendar |
// Check the authorization status of our application for Calendar |
-(void)checkEventStoreAccessForCalendar |
{ |
EKAuthorizationStatus status = [EKEventStore authorizationStatusForEntityType:EKEntityTypeEvent]; |
switch (status) |
{ |
// Update our UI if the user has granted access to their Calendar |
case EKAuthorizationStatusAuthorized: [self accessGrantedForCalendar]; |
break; |
// Prompt the user for access to Calendar if there is no definitive answer |
case EKAuthorizationStatusNotDetermined: [self requestCalendarAccess]; |
break; |
// Display a message if the user has denied or restricted access to Calendar |
case EKAuthorizationStatusDenied: |
case EKAuthorizationStatusRestricted: |
{ |
UIAlertController *alert = [UIAlertController alertControllerWithTitle:@"Privacy Warning" message:@"Permission was not granted for Calendar" |
preferredStyle:UIAlertControllerStyleAlert]; |
UIAlertAction *defaultAction = [UIAlertAction actionWithTitle:@"OK" |
style:UIAlertActionStyleDefault |
handler:^(UIAlertAction * action) {}]; |
[alert addAction:defaultAction]; |
[self presentViewController:alert animated:YES completion:nil]; |
} |
break; |
default: |
break; |
} |
} |
// Prompt the user for access to their Calendar |
-(void)requestCalendarAccess |
{ |
[self.eventStore requestAccessToEntityType:EKEntityTypeEvent completion:^(BOOL granted, NSError *error) |
{ |
if (granted) |
{ |
RootViewController * __weak weakSelf = self; |
// Let's ensure that our code will be executed from the main queue |
dispatch_async(dispatch_get_main_queue(), ^{ |
// The user has granted access to their Calendar; let's populate our UI with all events occuring in the next 24 hours. |
[weakSelf accessGrantedForCalendar]; |
}); |
} |
}]; |
} |
// This method is called when the user has granted permission to Calendar |
-(void)accessGrantedForCalendar |
{ |
// Let's get the default calendar associated with our event store |
self.defaultCalendar = self.eventStore.defaultCalendarForNewEvents; |
// Enable the Add button |
self.addButton.enabled = YES; |
// Fetch all events happening in the next 24 hours and put them into eventsList |
self.eventsList = [self fetchEvents]; |
// Update the UI with the above events |
[self.tableView reloadData]; |
} |
#pragma mark - |
#pragma mark Fetch events |
// Fetch all events happening in the next 24 hours |
- (NSMutableArray *)fetchEvents |
{ |
NSDate *startDate = [NSDate date]; |
//Create the end date components |
NSDateComponents *tomorrowDateComponents = [[NSDateComponents alloc] init]; |
tomorrowDateComponents.day = 1; |
NSDate *endDate = [[NSCalendar currentCalendar] dateByAddingComponents:tomorrowDateComponents |
toDate:startDate |
options:0]; |
// We will only search the default calendar for our events |
NSArray *calendarArray = @[self.defaultCalendar]; |
// Create the predicate |
NSPredicate *predicate = [self.eventStore predicateForEventsWithStartDate:startDate |
endDate:endDate |
calendars:calendarArray]; |
// Fetch all events that match the predicate |
NSMutableArray *events = [NSMutableArray arrayWithArray:[self.eventStore eventsMatchingPredicate:predicate]]; |
return events; |
} |
#pragma mark - |
#pragma mark Add a new event |
// Display an event edit view controller when the user taps the "+" button. |
// A new event is added to Calendar when the user taps the "Done" button in the above view controller. |
- (IBAction)addEvent:(id)sender |
{ |
// Create an instance of EKEventEditViewController |
EKEventEditViewController *addController = [[EKEventEditViewController alloc] init]; |
// Set addController's event store to the current event store |
addController.eventStore = self.eventStore; |
addController.editViewDelegate = self; |
[self presentViewController:addController animated:YES completion:nil]; |
} |
#pragma mark - |
#pragma mark EKEventEditViewDelegate |
// Overriding EKEventEditViewDelegate method to update event store according to user actions. |
- (void)eventEditViewController:(EKEventEditViewController *)controller |
didCompleteWithAction:(EKEventEditViewAction)action |
{ |
RootViewController * __weak weakSelf = self; |
// Dismiss the modal view controller |
[self dismissViewControllerAnimated:YES completion:^ |
{ |
if (action != EKEventEditViewActionCanceled) |
{ |
dispatch_async(dispatch_get_main_queue(), ^{ |
// Re-fetch all events happening in the next 24 hours |
weakSelf.eventsList = [self fetchEvents]; |
// Update the UI with the above events |
[weakSelf.tableView reloadData]; |
}); |
} |
}]; |
} |
// Set the calendar edited by EKEventEditViewController to our chosen calendar - the default calendar. |
- (EKCalendar *)eventEditViewControllerDefaultCalendarForNewEvents:(EKEventEditViewController *)controller |
{ |
return self.defaultCalendar; |
} |
@end |
Copyright © 2015 Apple Inc. All Rights Reserved. Terms of Use | Privacy Policy | Updated: 2015-09-16