How to delete calendar events faster?

Question

Following code works and deletes all calendar events from iPhone calendar database. But events are deleting very slow: 2 events per second on iPhone 3GS. So if you have 3000 events - then it's 25 minutes to erase them... How would you optimize this code? Maybe I am doing something wrong? Thanks.

- (void)deleteAllCalendarEventsFromIPhone:(NSError **)error {
    EKEventStore *store = [[EKEventStore alloc] init];

    NSUInteger beginYear = 1900;
    NSUInteger endYear = 2100;

    while (beginYear < endYear) {
        NSPredicate *predicate = 
            [store predicateForEventsWithStartDate:[self createDateWithYear:beginYear month:1 day:1] 
                                           endDate:[self createDateWithYear:beginYear + 4 month:1 day:1] 
                                         calendars:nil];
        NSArray *eventList = [store eventsMatchingPredicate:predicate];
        for (EKEvent *event in eventList) {         
            success = [store removeEvent:event span:EKSpanThisEvent error:nil];
        }
        beginYear += 4;
    }
    [store release];
}

score 1 · Answer 1 · answered Sep 22 '11 at 08:35

1

iOS 5.0 has a new removeEvent: method that allows you not to commit changes until the very end. I haven't tested it yet, but that sounds to be exactly what you need here.

answered Sep 22 '11 at 08:35

Joe Miranda

11
1

score 0 · Answer 2 · answered Oct 28 '10 at 07:34

0

Maybe because it is not the usage of EKEventStore !
Removing all user event is quite dangerous ...

answered Oct 28 '10 at 07:34

Benoît

7,395
2
25
30

I disagree with you. It's the usage of EKEventStore. I receiving GroupWise calendars (5000 events) and saving it in iPhone calendar app (using prefix GW at the beginning of event name). And then, if user don't need these events in iCal - he can delete it, using my function. – arthur_skypro Oct 28 '10 at 08:24

score 0 · Answer 3 · edited May 10 '11 at 17:18

-(void)deleteElementFromCalendarDB {
    CFGregorianDate gregorianStartDate, gregorianEndDate;
    CFGregorianUnits startUnits = {-2, 0, 0, 0, 0, 0}; 
    CFGregorianUnits endUnits = {1, 0, 0, 0, 0, 0};
    CFTimeZoneRef timeZone = CFTimeZoneCopySystem();
    gregorianStartDate =  CFAbsoluteTimeGetGregorianDate(
        CFAbsoluteTimeAddGregorianUnits(CFAbsoluteTimeGetCurrent(),
        timeZone,startUnits),timeZone);
    gregorianStartDate.hour = 0;
    gregorianStartDate.minute = 0;
    gregorianStartDate.second = 0;
    gregorianEndDate = CFAbsoluteTimeGetGregorianDate(
        CFAbsoluteTimeAddGregorianUnits(CFAbsoluteTimeGetCurrent(),
        timeZone, endUnits),timeZone);
    gregorianEndDate.hour = 0; 
    gregorianEndDate.minute = 0; 
    gregorianEndDate.second = 0;
    NSDate* startDate = [NSDate dateWithTimeIntervalSinceReferenceDate:
    CFGregorianDateGetAbsoluteTime(gregorianStartDate, timeZone)];
    NSDate* endDate =   [NSDate dateWithTimeIntervalSinceReferenceDate:
    CFGregorianDateGetAbsoluteTime(gregorianEndDate, timeZone)];
    CFRelease(timeZone);
    NSError *err;
    NSPredicate *predicate = [self.eventStore predicateForEventsWithStartDate:startDate
        endDate:endDate
        calendars:nil];
    NSArray *eventListS = [self.eventStore eventsMatchingPredicate:predicate];
    for (EKEvent *event in eventListS) {           
        [self.eventStore removeEvent:event span:EKSpanFutureEvents error:&err];
    }
    if (err == noErr) {
        UIAlertView *alert =[[UIAlertView alloc]itWithTitle:@"All Events were deleted"                                              message:@"How about that?" 
            delegate:nil
            cancelButtonTitle:@"Okay" 
            otherButtonTitles:nil];
        [alert show];
        [alert release];
    }
}

I think that it will be better if you use these followings lines of code. — I_Man, May 10 '11 at 16:40

How to delete calendar events faster?

3 Answers3