Question

I’ve tried to implement the following with my locationManager:

STARTING TO UPDATE THE USERS LOCATION

- (void)startStandardUpdates {
    if (self.locationManager == nil) {
        self.locationManager = [[CLLocationManager alloc] init];
    }

    self.locationManager.delegate = self;
    self.locationManager.desiredAccuracy = kCLLocationAccuracyBest;

    // Set a movement threshold for new events
    self.locationManager.distanceFilter = kCLLocationAccuracyNearestTenMeters;

    [self.locationManager startUpdatingLocation];

    CLLocation *currentLocation = self.locationManager.location;

    if (currentLocation) {
        self.currentLocation = currentLocation;
    }
}

IMPLEMENTING A CUSTOM SETTER FOR MY PROPERTY TO SEND NOTIFICATIONS

- (void)setCurrentLocation:(CLLocation *)currentLocation {
    self.currentLocation = currentLocation;
    NSLog(@"%f", currentLocation.coordinate.latitude);

    //Notify the app of the location change
    NSDictionary *userInfo = [NSDictionary dictionaryWithObject:self.currentLocation forKey:kIFLocationKey];
    dispatch_async(dispatch_get_main_queue(), ^{
        [[NSNotificationCenter defaultCenter] postNotificationName:kIFLocationChangeNotification object:nil userInfo:userInfo];
    });
}

THE PROBLEM IS:
when I run the app, I get a “BAD_EXEC (code 2)” error message in the “setCurrentLocation” method in the debug mode and the app has hung up. But I don’t get the issue. Did I miss something out? As far as I see it, in “startStandardUpdates”, if the location manager has found a user’s location, the property “currentLocation” is being updated, using my custom setter “self.currentLocation = currentLocation”.

Thanks for your help in advance!
regards
Sebastian

Answer 1

The way you implemented the setter is the problem. self.currentLocation = … causes the setter to be called and you call it while implementing the setter, which is causing an infinite loop. Synthesize your ivar as below, and use _variablename only in the setters (and getters).

@synthesize currentLocation = _currentLocation;

//Setter

- (void)setCurrentLocation:(CLLocation *)currentLocation {
    _currentLocation = currentLocation;
    NSLog(@"%f", currentLocation.coordinate.latitude);

    //Notify the app of the location change
    NSDictionary *userInfo = [NSDictionary dictionaryWithObject:self.currentLocation forKey:kIFLocationKey];
    dispatch_async(dispatch_get_main_queue(), ^{
        [[NSNotificationCenter defaultCenter] postNotificationName:kIFLocationChangeNotification object:nil userInfo:userInfo];
    });
}