iOS CLLocationManagerDelegate didUpdateToLocation is not being called - ios

Question

I'm creating an app that uses core location and this is my code:
the .h :
#import <UIKit/UIKit.h>
#import <CoreLocation/CoreLocation.h>
#interface ViewController : UIViewController
<CLLocationManagerDelegate>
#property(strong,nonatomic) CLLocationManager *manager;
#end
the .m :
#import "ViewController.h"
#import <CoreLocation/CoreLocation.h>
#interface ViewController ()
#end
#implementation ViewController
#synthesize manager;
- (void)didReceiveMemoryWarning {
[super didReceiveMemoryWarning];
}
- (void)viewDidLoad
{
[super viewDidLoad];
if (!self.manager)
{
self.manager=[CLLocationManager new];
}
self.manager.delegate = self;
self.manager.desiredAccuracy = kCLLocationAccuracyBestForNavigation;
[self.manager startUpdatingLocation];
}
- (void)locationManager:(CLLocationManager *)manager didUpdateLocations:(NSArray *)locations
{
CLLocation * currentLocation = (CLLocation *)[locations lastObject];
NSLog(#"Location: %#", currentLocation);
if (currentLocation != nil)
{
NSLog([NSString stringWithFormat:#"%.8f", currentLocation.coordinate.latitude]);
NSLog([NSString stringWithFormat:#"%.8f", currentLocation.coordinate.longitude]);
}
}
#end
the problem is didUpdateToLocation is not being called.
I tried putting a breakpoint inside of it and nothing happened.

Answer 1

For iOS location tracking to work correctly, here are the prerequisites, and the order is of importance, too:
Define your class as CLLocationManagerDelegate.
Instantiate CLLocationManager instance.
Set its delegate to self.
Set its various properties (accuracy etc)
Call [CLLocationManagerDelegate startUpdatingLocation] when you intend to.
Listen to location updates within your delegate method didUpdateLocations, implemented within the class designated as CLLocationManagerDelegate.
With your code, here are the things you need to correct:
-(IBAction)submit
{
[self.manager startUpdatingLocation];
}
- (void)viewDidLoad
{
[super viewDidLoad];
if (!self.manager)
{
self.manager=[CLLocationManager new];
}
self.manager.delegate = self;
self.manager.desiredAccuracy = kCLLocationAccuracyBestForNavigation;
}
In short, before telling it to start updating location, you need to instantiate it and set its properties right. Currently you are doing it the reverse way.
UPDATE
Also, your delegate method didUpdateToLocation is deprecated since iOS 6. You must replace it with newer method, like this:
- (void)locationManager:(CLLocationManager *)manager didUpdateLocations:(NSArray *)locations
{
CLLocation * currentLocation = (CLLocation *)[locations lastObject];
NSLog(#"Location: %#", currentLocation);
if (currentLocation != nil)
{
self.latitude.text = [NSString stringWithFormat:#"%.8f", currentLocation.coordinate.latitude];
self.longitude.text = [NSString stringWithFormat:#"%.8f", currentLocation.coordinate.longitude];
}
}

Answer 2

You need to add these keys to your Info.plist:
NSLocationWhenInUseUsageDescription
NSLocationAlwaysUsageDescription
And also request for the type you want to authorise if iOS8:
if ([self.locationManager respondsToSelector:#selector(requestWhenInUseAuthorization)])
{
[self.locationManager requestWhenInUseAuthorization];
}
[self.locationManager startUpdatingLocation];
So the system will display the alert "Allow "app" to access your location...? Allowing will start your location manager and didUpdateLocations will be called.