CLLocationManager delegate not called

Question

I am using CLLocationManager on device and the delegate methods aren't getting called. Here's my code (I can see that the class isn't getting deallocated either):

#import <Foundation/Foundation.h>
#import <CoreLocation/CoreLocation.h>

@interface CurrentLocation : NSObject <CLLocationManagerDelegate> {
    CLLocationManager *locationManager;

}
@property (nonatomic, retain) CLLocationManager *locationManager;  

@end

#import "CurrentLocation.h"
#import "SBJson.h"
@implementation CurrentLocation
@synthesize locationManager;

- (id)init
{
    self = [super init];
    if (self) {
        NSLog(@"Initialized");
        locationManager = [[[CLLocationManager alloc] init] autorelease];
        locationManager.delegate = self;
        [locationManager startUpdatingLocation];
        BOOL enable = [CLLocationManager locationServicesEnabled];
        NSLog(@"%@", enable? @"Enabled" : @"Not Enabled");
    }

    return self;
}

- (void)locationManager:(CLLocationManager *)manager
    didUpdateToLocation:(CLLocation *)newLocation
           fromLocation:(CLLocation *)oldLocation {
    NSLog(@"A");
    NSString *stringURL = [NSString stringWithFormat:@"http://maps.googleapis.com/maps/api/geocode/json?latlng=%f,%f&sensor=true", newLocation.coordinate.latitude, newLocation.coordinate.longitude];
    NSLog(@"%@", stringURL);

    NSURL *url = [NSURL URLWithString:stringURL];

    NSData *data = [NSURLConnection sendSynchronousRequest:[NSURLRequest requestWithURL:url] returningResponse:nil error:nil];

    SBJsonParser *parser = [[SBJsonParser alloc] init];
    NSDictionary *dict = [parser objectWithData:data];
    NSLog(@"%@", dict);
}

- (void)locationManager:(CLLocationManager *)manager didFailWithError:(NSError *)error {
    NSLog(@"B");
}

- (void)dealloc {
    NSLog(@"Dealloc called");
    [super dealloc];
    [locationManager release];
}

@end

In log, I see:

2011-10-02 19:49:04.095 DixieMatTracker[1404:707] Initialized
2011-10-02 19:49:04.109 DixieMatTracker[1404:707] Enabled

What am I doing wrong? Thanks

Unlikely to make a difference, but I've seen stranger things. Put self.locationManager (to access property). Without self, it accesses backing variable, without retaining (as you have autoreleased). — Daryl Teo, Oct 03 '11 at 00:00
@PragmaOnce Is it `assign`, `retain`, what? Try using `self.locationManager` instead. @Daryl Teo I agree, this is likely the problem as `locationManager` will be autoreleased. — , Oct 03 '11 at 00:03
`[super dealloc]` should be called at the end of your custom `dealloc` implementation, not first. — Leslie Godwin, Sep 01 '15 at 10:14

score 6 · Accepted Answer · answered Oct 03 '11 at 00:09

6

You're using the locationManager ivar, not the property; this means that the CLLocationManager isn't being retained and will be deallocated as you're autoreleasing it. Use self.locationManager:

self.locationManager = [[[CLLocationManager alloc] init] autorelease];

answered Oct 03 '11 at 00:09

Can't believe i didn't catch that... :(. Thanks. – 0xSina Oct 03 '11 at 05:02

score 3 · Answer 2 · answered Oct 03 '11 at 00:00

I would suggest that you check your memory management on your CLLocationManager instance.

Write it so:

#import "CurrentLocation.h"
#import "SBJson.h"
@implementation CurrentLocation
@synthesize locationManager;

- (id)init
{
    self = [super init];
    if (self) {
        NSLog(@"Initialized");
        locationManager = [[CLLocationManager alloc] init];
        locationManager.delegate = self;
        [locationManager startUpdatingLocation];
        BOOL enable = [CLLocationManager locationServicesEnabled];
        NSLog(@"%@", enable? @"Enabled" : @"Not Enabled");
    }

    return self;
}

- (void)locationManager:(CLLocationManager *)manager
    didUpdateToLocation:(CLLocation *)newLocation
           fromLocation:(CLLocation *)oldLocation {
    NSLog(@"A");
    NSString *stringURL = [NSString stringWithFormat:@"http://maps.googleapis.com/maps/api/geocode/json?latlng=%f,%f&sensor=true", newLocation.coordinate.latitude, newLocation.coordinate.longitude];
    NSLog(@"%@", stringURL);

    NSURL *url = [NSURL URLWithString:stringURL];

    NSData *data = [NSURLConnection sendSynchronousRequest:[NSURLRequest requestWithURL:url] returningResponse:nil error:nil];

    SBJsonParser *parser = [[SBJsonParser alloc] init];
    NSDictionary *dict = [parser objectWithData:data];
    NSLog(@"%@", dict);
}

- (void)locationManager:(CLLocationManager *)manager didFailWithError:(NSError *)error {
    NSLog(@"B");
}

- (void)dealloc {
    NSLog(@"Dealloc called");
    [super dealloc];
    [locationManager release];
}

@end

The delegate does not get called because the CLLocationManager object is deallocated before it can provide a response to the location request. This is caused by the autorelease in your code.

Besides that - iff autorelease is used it would be a mistake to manually release it in dealloc. This could lead to unexpected crashes.

The solution above does it 'by-hand' allocating a CLLocationManager in init and releasing it in dealloc.

Wow. that worked. Still don't understand why the CLLocationManager instance was deallocated...I am autoreleasing and then using the accuser to retain it. Anyways, thanks a lot. — 0xSina, Oct 03 '11 at 00:04
This doesn't solve the underlying problem: the property isn't being used. — , Oct 03 '11 at 00:11
Use of the property was not asked.. BTW this is exactly what happens if the property was defined as retain and has been properly accessed using self.locationManager — Wizz, Oct 03 '11 at 00:15

score 0 · Answer 3 · answered Mar 22 '15 at 09:57

In my case it was because of my device was unable to determine location - while staying indoors GPS signal was unavailable and wi-fi was also disconnected so location manager just wasn't able to receive any location data and delegate was never called.

Once I've connected wi-fi it worked (I guess moving outdoors should also do the trick in that case, but sometimes it is not very convenient way :) )

CLLocationManager delegate not called

3 Answers3