EventKit last event of calendar - ios

I'm making an app in which I sync certain events to a calendar on iPhone.
The problem is, I have no way of telling which events were altered/removed/...
So I need to remove all the events between today and the end date of the last event of the calendar before 'syncing' (read inserting) the new events.
As far as I've seen, the only way to do an action on multiple events at once, is by using enumerateEventsMatchingPredicate:usingBlock: and predicateForEventsWithStartDate:endDate:calendars:
But for this I need a specific end date. (and thus, the end date of the last event in my calendar)
I could always save the event identifier of the last event I insert into this calendar, but I would rather not do this:
If the user uninstalls my app and installs it again later, I don't have the last event identifier anymore. (given that (s)he didn't remove the calendar manually of course)
I could just remove the calendar every time I need to sync the calendar, but then I would lose all passed events.
Any ideas or tips are much appreciated!

For your comment on :
I can't seem to find any way to fetch all the events of a calendar.
Actually you can fetch all the events from calendar :
NSDate *start = ...
NSDate *finish = ...
// use Dictionary for remove duplicates produced by events covered more one year segment
NSMutableDictionary *eventsDict = [NSMutableDictionary dictionaryWithCapacity:1024];
NSDate* currentStart = [NSDate dateWithTimeInterval:0 sinceDate:start];
int seconds_in_year = 60*60*24*365;
// enumerate events by one year segment because iOS do not support predicate longer than 4 year !
while ([currentStart compare:finish] == NSOrderedAscending) {
NSDate* currentFinish = [NSDate dateWithTimeInterval:seconds_in_year sinceDate:currentStart];
if ([currentFinish compare:finish] == NSOrderedDescending) {
currentFinish = [NSDate dateWithTimeInterval:0 sinceDate:finish];
}
NSPredicate *predicate = [eventStore predicateForEventsWithStartDate:currentStart endDate:currentFinish calendars:nil];
[eventStore enumerateEventsMatchingPredicate:predicate
usingBlock:^(EKEvent *event, BOOL *stop) {
if (event) {
[eventsDict setObject:event forKey:event.eventIdentifier];
}
}];
currentStart = [NSDate dateWithTimeInterval:(seconds_in_year + 1) sinceDate:currentStart];
}
NSArray *events = [eventsDict allValues];

Related

iOS: predicateForEventsWithStartDate does not return events starting outside of search frame

Simple example I use with the code in the snippet below:
Search frame: 15 Apr 2016 15:00pm-18:00pm
Events which are entered in the calendar:
Event 1: 15 Apr 2016 12:00pm-16:00pm
Event 2: 15 Apr 2016 17:00pm-20:00pm
Now the used method returns me only one object - that is the Event 2. Apparently I hope to get returned both - Event 1 and 2.
I really don't understand why this happens! What do I miss in my code? Thanks in advance.
int seconds_in_year = 60*60*24*365;
__block
NSDate* currentStart = [NSDate dateWithTimeInterval:0 sinceDate:startTime];
__block
NSDate* currentFinish = [NSDate dateWithTimeInterval:seconds_in_year sinceDate:currentStart];
// use Dictionary for remove duplicates produced by events covered more one year segment
NSMutableDictionary *eventsDict = [NSMutableDictionary dictionaryWithCapacity:1024];
EKEventStore *store = [[EKEventStore alloc] init];
[store requestAccessToEntityType:EKEntityTypeEvent completion:^(BOOL granted, NSError *error) {
if (!granted) { return; }
// enumerate events by one year segment because iOS do not support predicate longer than 4 year !
while ([currentStart compare:endTime] == NSOrderedAscending) {
if ([currentFinish compare:endTime] == NSOrderedDescending) {
currentFinish = [NSDate dateWithTimeInterval:0 sinceDate:endTime];
}
NSPredicate *predicate = [store predicateForEventsWithStartDate:currentStart endDate:currentFinish calendars:nil];
[store enumerateEventsMatchingPredicate:predicate
usingBlock:^(EKEvent *event, BOOL *stop) {
if (event) {
[eventsDict setObject:event forKey:event.eventIdentifier];
}
}];
currentStart = [NSDate dateWithTimeInterval:(seconds_in_year + 1) sinceDate:currentStart];
}
return;
}];
EDIT:
If I try another Event 3 (15 Apr 2016 14:00pm-19:00pm) then the method returns me the whole search period as to be an "event" in the calendar. That is correct compared to the previous situation which still causes me some headaches.
As the method name implies predicateForEventsWithStartDate searches for startDates which are equal to or later than the passed date argument.

Receiving An Intermittent EXC_BAD_ACCESS When Updating an EKEvent

I have a Cordova app with a custom plugin that is creating and updating EKEvents in the user's iCloud calendar.
I am using the following function to find a specific EKEvent based on its URL:
- (EKEvent*) getEventWithURL:(NSString *)pstrURL store:(EKEventStore *)pStore
{
EKCalendar* calendar = [self getCalendarByName:mstrCalendarName store:pStore createIfDoesNotExist:false];
NSArray* calendars = [[NSArray alloc] initWithObjects: calendar, nil];
NSDateFormatter *sDate = [[NSDateFormatter alloc] init];
[sDate setDateFormat:#"yyyy-MM-dd HH:mm"];
NSDate *myStartDate = [sDate dateFromString:#"2013-11-01 00:00"];
NSDateFormatter *eDate = [[NSDateFormatter alloc] init];
[eDate setDateFormat:#"yyyy-MM-dd HH:mm"];
NSDate *myEndDate = [eDate dateFromString:#"2014-12-31 23:59"];
NSPredicate *predicate = [pStore predicateForEventsWithStartDate:myStartDate endDate:myEndDate calendars: calendars];
// Fetch all events that match the predicate.
NSArray *events = [pStore eventsMatchingPredicate:predicate];
EKEvent *foundEvent = nil;
EKEvent *event;
for (id oEvent in events)
{
event = (EKEvent *)oEvent;
if ([event.URL isEqual:[NSURL URLWithString:pstrURL]])
{
foundEvent = event;
break;
}
}
return foundEvent;
}
It is then modified (start and end dates are changed) and saved in another method with the following code:
EKEvent *myEvent = nil;
BOOL saved = false;
EKCalendar* calendar = nil;
if(pstrCalendarTitle == nil)
{
calendar = pStore.defaultCalendarForNewEvents;
}
else
{
calendar = [self getCalendarByName: pstrCalendarTitle store: pStore createIfDoesNotExist:true];
}
// find event if it exists
myEvent = [self getEventWithURL:[NSString stringWithFormat: #"custom://%#", pstrTSDID ] store:pStore];
// if an event wasn't found, create a new one
if (myEvent == nil)
{
myEvent = [EKEvent eventWithEventStore: pStore];
}
// set all the fields to new values
myEvent.title = pstrTitle;
myEvent.location = pstrLocation;
myEvent.notes = pstrMessage;
myEvent.startDate = pdtStartDate;
myEvent.endDate = pdtEndDate;
myEvent.calendar = calendar;
myEvent.URL = [NSURL URLWithString:[NSString stringWithFormat: #"custom://%#", pstrTSDID ]];
// only add an alarm if one hasn't been created already
if ([[myEvent alarms] count] == 0)
{
EKAlarm *reminder = [EKAlarm alarmWithRelativeOffset:-2*60*60];
[myEvent addAlarm:reminder];
}
When creating a whole bunch of EKEvents (about 30 in a row) I don't get the EXC_BAD_ACCESS error, however when updating events I get the EXC_BAD_ACCESS error intermittently. Sometimes it is on the first update, and sometimes I am able to update 10 before seeing the error, which then crashes my app.
I suspect it may have something to do with the foundEvent variable not being retained, however my project is using ARC so it is my understanding that I don't need to do any memory management tasks. Unless ARC is getting confused with the way the event variable is being cast and then passed around in the loop in getEventWithURL?
For full disclosure, I do have Enable Zombie Objects enabled and the stack trace that I see doesn't reference any of my methods specifically, it starts at start_wqthread and then references some EKEventStore _databasechangedexternally internal methods.
For what it's worth I wasn't able to figure out what the issue was with modifying the events so I am instead deleting the event (if it exists) and creating a new one. My getEventWithURL method is now called deleteEventWithURL which does the removal of the event from the store. The app is no longer crashing after making this change.

Handling EKEventStoreChangedNotification notification

I am listing the events in my app. User can create, edit and delete the events. In viewDidLoad method I fetch all events I need and push them into an array. It works like expected.
For creating, editing and deleting events I use EKEventEditViewController and EKEventViewController which works pretty well. In delegate methods of the controllers I make the changes I need on my array and reload my view.
Of course I would like also know and handle, if user make some changes from another app (like built-in calendar app). So I observe EKEventStoreChangedNotification. From that notification I get only "changes have been occurred" and not which event or from which app. Actually what I want to know is, if the change has been occurred from my app or another app and which events have been changed. Since I already handle the changes(from my app) in EKEventEditViewControllerDelegate method, I do not need to handle them again.
If I do not know which objects have been changed, I have to fetch ans sort all of them.
For now I have only 5 events in the calendar(development device), of course it is not a problem to fetch and sort all events, but if user has more then 1000, it is overkill for maybe only one event change.
So my question is: How to handle EKEventStoreChangedNotification?
You can detect exactly which event has been changed by the following code [Disclaimer code is not my idea, I have found it in another Stack Overflow answer and modified it a little bit].
I'm using a lib called "JSCalendarManager" for interaction with eventstore and in my case as the events created using my App and synced with iCalendar I already saved their eventIdentifier in local DB , I can retrieve my time bound to search for events in iCalendar and get match for changed one.
+(void)iCloudStoreChanged:(NSNotification*)eventStoreChangeNotification{
NSArray* allScheduleRecords =[self getAllScheduleRecordSyncedToICalendar];
NSDate* startDate = [NSDate new];
NSDate* endDate = [NSDate new];
NSDateFormatter *dateFormatter = [[NSDateFormatter alloc] init];
[dateFormatter setDateFormat:#"yyyy-MM-dd HH:mm:ss"];
if (allScheduleRecords.count >= 2) {
startDate = [dateFormatter dateFromString:[[allScheduleRecords firstObject] objectForKey:#"meetingTime"]];
endDate = [dateFormatter dateFromString:[[allScheduleRecords lastObject] objectForKey:#"meetingTime"]];
}else if (allScheduleRecords.count > 0){
startDate = [dateFormatter dateFromString:[[allScheduleRecords firstObject] objectForKey:#"meetingTime"]];
NSDate *today = [NSDate date];
NSCalendar *gregorian = [[NSCalendar alloc] initWithCalendarIdentifier:NSGregorianCalendar];
NSDateComponents *components = [gregorian components:(NSEraCalendarUnit | NSYearCalendarUnit | NSMonthCalendarUnit) fromDate:today];
components.day = 1;
endDate = [gregorian dateFromComponents:components];
}else{
}
NSArray *ekEventStoreChangedObjectIDArray = [eventStoreChangeNotification.userInfo objectForKey:#"EKEventStoreChangedObjectIDsUserInfoKey"];
[calendarManager findEventsBetween:startDate
and:endDate
withSearchHandler:^(BOOL found, NSError *error, NSArray *eventsArray) {
[eventsArray enumerateObjectsUsingBlock:^(EKEvent *ekEvent, NSUInteger idx, BOOL *stop) {
// Check this event against each ekObjectID in notification
[ekEventStoreChangedObjectIDArray enumerateObjectsUsingBlock:^(NSString *ekEventStoreChangedObjectID, NSUInteger idx, BOOL *stop) {
NSObject *ekObjectID = [(NSManagedObject *)ekEvent objectID];
if ([ekEventStoreChangedObjectID isEqual:ekObjectID]) {
// Log the event we found and stop (each event should only exist once in store)
NSLog(#"calendarChanged(): Event Changed: title:%#", ekEvent.title);
[self updateAppointmentForEvent:ekEvent];
*stop = YES;
}
}];
}];
}];}
Instead of fetching all events, can you not update only the events that are onscreen/active.

How to detect which EKevent was changed

I got the problem. I need to know when Events in my EventStore are changed, so for this case I use EKEventStoreChangedNotification but this notification return to me incomprehensible dictionary in userInfo
It's look like this:
EKEventStoreChangedObjectIDsUserInfoKey = ("x-apple-eventkit:///Event/p429" );
I don't know how I can use this data to taking access for changed object. Please help me
This will detect changed events and log the event titles over a date range. Although, I ended up not doing this because in practice I don't know the date range. I need to compare with all the events I'm working with, which means I need to refresh them anyway since the object IDs might have changed. This ends up making each event not so useful and now I just refresh every few seconds when changes come in and ignore the details. I hope Apple improves these notifications.
#pragma mark - Calendar Changed
- (void)calendarChanged:(NSNotification *)notification {
EKEventStore *ekEventStore = notification.object;
NSDate *now = [NSDate date];
NSDateComponents *offsetComponents = [NSDateComponents new];
[offsetComponents setDay:0];
[offsetComponents setMonth:4];
[offsetComponents setYear:0];
NSDate *endDate = [[NSCalendar currentCalendar] dateByAddingComponents:offsetComponents toDate:now options:0];
NSArray *ekEventStoreChangedObjectIDArray = [notification.userInfo objectForKey:#"EKEventStoreChangedObjectIDsUserInfoKey"];
NSPredicate *predicate = [ekEventStore predicateForEventsWithStartDate:now
endDate:endDate
calendars:nil];
// Loop through all events in range
[ekEventStore enumerateEventsMatchingPredicate:predicate usingBlock:^(EKEvent *ekEvent, BOOL *stop) {
// Check this event against each ekObjectID in notification
[ekEventStoreChangedObjectIDArray enumerateObjectsUsingBlock:^(NSString *ekEventStoreChangedObjectID, NSUInteger idx, BOOL *stop) {
NSObject *ekObjectID = [(NSManagedObject *)ekEvent objectID];
if ([ekEventStoreChangedObjectID isEqual:ekObjectID]) {
// Log the event we found and stop (each event should only exist once in store)
NSLog(#"calendarChanged(): Event Changed: title:%#", ekEvent.title);
*stop = YES;
}
}];
}];
}

iOS/Xcode: Cannot find recurrent events with predicateForEventsWithStartDate and startDate and endDate outside my search range

In iOS events are stored by their startDate and endDate and their recurrence rules.
If i want to fetch all events for the next 3 days i only get events with the start date within the next three days.
BUT: i do not get events, which are recurring and their startDate is not within my search range, i suppose the reason is that the iOS Calendar is computing on the fly all days when the event occurs, but does not use this information when searching programmaticaly in the EKEventStore.
So ist there a way to find recurring events within my "search date frame" when their startDate is outside the range and some recurrence rules are applied?
best regards,
Christian
NSDate *date_today = [self dateAtBeginningOfDayForDate:[NSDate date]];
NSDate *endDate = [self dateByAddingDays:3 toDate:date_today];
NSPredicate *searchPredicate = [eventStore predicateForEventsWithStartDate:date_today
endDate:endDate calendars:nil];
NSArray *events = [eventStore eventsMatchingPredicate:searchPredicate];

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