CLLocationManager is alive even when not needed - ios

Question

I have a mapping functionality in my app. It belongs to one of the Tab Bar controller tabs.
The problem I have is that the app is asking for location permissions right after launch.
I dont want to bother the user with location related questions until he actually goes to that map part of the app.
If I understand properly, location manager should not bother to ask for that until I instantiate it. Also, as soon as the user leaves that map part of the app, either by selecting other tabs or by pressing home button..I nil the location manager.
Why is it then asking for that so soon? My question is whether there is some special rule in this particular case...or it is caused by my flawed app design?

Answer 1

I'd go with the "flowed app design" one. You don't showed any code, so it's hard to say, but UITabBarController instantiates all its View Controllers at once, so your CCLocation class is probably being initialized with your TabBar.
What you could do is: initialize your CCLocation stuff only on the -viewWillAppear method on the View Controller that you actually use it.

Answer 2

You can write something like this.
h:
#import <Foundation/Foundation.h>
#import <CoreLocation/CoreLocation.h>
#interface LocationController : NSObject <CLLocationManagerDelegate> {
CLLocationManager *locationManager;
CLLocation *currentLocation;
}
+ (LocationController *)sharedInstance;
- (void)start;
- (void)stop;
#property (nonatomic, strong) CLLocation *currentLocation;
#end
m:
#import "LocationController.h"
#implementation LocationController
static LocationController *sharedInstance;
+ (LocationController *)sharedInstance {
static LocationController *sharedClient;
static dispatch_once_t onceToken;
dispatch_once(&onceToken, ^{
sharedClient = [[LocationController alloc] init];
});
return sharedClient;
}
-(id) init {
if (self = [super init]) {
currentLocation = [[CLLocation alloc] init];
locationManager = [[CLLocationManager alloc] init];
locationManager.delegate = self;
[self start];
}
return self;
}
- (void)start {
[locationManager startUpdatingLocation];
}
- (void)stop {
[locationManager stopUpdatingLocation];
}
- (void)locationManager:(CLLocationManager *)manager didUpdateLocations:(NSArray *)locations {
CLLocation *loc = [locations lastObject];
if ( abs([loc.timestamp timeIntervalSinceDate: [NSDate date]]) < 120) {
self.currentLocation = loc;
}
}
- (void)locationManager:(CLLocationManager *)manager didFailWithError:(NSError *)error {
NSLog(#"%#", error);
}
#end
Then whenever you need to locate you can do the following:
[[LocationController sharedInstance] start];

Answer 3

Where are you instantiating the CLLocationManager? While all the view controllers are instantiated when the tab bar controller is instantiated, their respective views are not created until you go to the relevant tab. So, if you're instantiating your CLLocationManager in one of the controller's init methods, then that location manager will be created when the controllers are (i.e. when the tab bar controller is instantiated). If you have the instantiation of the location manager in viewDidLoad, though, it shouldn't be instantiated until you click on the appropriate tab.