Question

Is it OK to put the CLLocationManager Delegate methods in a Singleton class which is a subclass of NSObject instead of UIViewController? I would like to do this as Id like to invoke the Singleton from the App Delegate and start getting the coordinates while the UI is loading

I have a locationcontroller class and I have the following initialization code in it

static locationController *sharedLocController = NULL;
+(locationController *) getSharedController
{   
    if (sharedLocController !=nil)
    {
        NSLog(@"locationController has already been created.....");
        return sharedLocController;
    }
    @synchronized(self)
    {
        if (sharedLocController == nil)
        {
            sharedLocController = [[self alloc] init];

        }
    }
    return sharedLocController;
}
//==============================================================================
+(id)alloc
{

    @synchronized([locationController class])
    {

        NSAssert(sharedLocController == nil, @"Attempted to allocate a second instance of a sharedLocMgr singleton.");
        sharedLocController = [super alloc];
        return sharedLocController;
    }
    return nil;
}
//==============================================================================
-(id)init
{
    self = [super init];

    if(sharedLocController !=nil)
    {

        if(!self.locMgr)
        {
            [self initLocationManager];

        }
    }



    return sharedLocController;
}
//==============================================================================
-(void)initLocationManager
{


    self.locMgr = [[CLLocationManager alloc] init];

    self.locMgr.delegate = self;
    self.locMgr.distanceFilter = kCLDistanceFilterNone;
    self.locMgr.desiredAccuracy = kCLLocationAccuracyBest;
    [self.locMgr startUpdatingLocation];
    NSLog(@"location manager object %@", locMgr);
}

Problem is that the self.locMgr object is always null.
Thanks

Answer 1

Get rid of your alloc function. It isn’t necessary and is returning nil, which means this init call is getting called on a nil pointer:

sharedLocController = [[self alloc] init];