prompting for location authorization in iOS8 - ios8

Question

I have looked at other similar questions on this site, apple dev site and countless YouTube videos but I am still unable to figure this out. There seems to be very little info on getting a user's location in Xcode/iOS8.
I have a map view that works fine except when I click on a button to get my location, nothing happens and in the logs I see
Trying to start MapKit location updates without prompting for location authorization. Must call -[CLLocationManager requestWhenInUseAuthorization] or -[CLLocationManager requestAlwaysAuthorization] first.
I don't understand what I am doing wrong. I am very new to programming and all information I have seen doesn't make much sense to me.
I'm using storyboards in my app, and the code specific to this is as follows:
mapViewController.h
#import <UIKit/UIKit.h>
#import <MapKit/MapKit.h>
#import <CoreLocation/CoreLocation.h>
#interface mapViewController : UIViewController {
MKMapView *mapview;
}
#property (nonatomic, retain) IBOutlet MKMapView *mapview;
-(IBAction)setMap:(id)sender;
-(IBAction)getCurrentLocation:(id)sender;
#property (nonatomic, retain) IBOutlet CLLocationManager *locationManager;
#end
mapViewController.m
#import "mapViewController.h"
#interface mapViewController ()
#end
#implementation mapViewController {
CLLocationManager *locationManager;
}
#synthesize mapview;
- (void)viewDidLoad {
[super viewDidLoad];
// Do any additional setup after loading the view.
self.locationManager.delegate=self;
self.locationManager.desiredAccuracy = kCLLocationAccuracyBest;
self.locationManager.requestWhenInUseAuthorization;
}
- (void)didReceiveMemoryWarning {
[super didReceiveMemoryWarning];
// Dispose of any resources that can be recreated.
}
-(IBAction)setMap:(id)sender {
switch (((UISegmentedControl *) sender).selectedSegmentIndex) {
case 0:
mapview.mapType = MKMapTypeStandard;
break;
case 1:
mapview.mapType = MKMapTypeSatellite;
break;
case 2:
mapview.mapType = MKMapTypeHybrid;
break;
default:
break;
}
}
-(IBAction)getCurrentLocation:(id)sender {
mapview.showsUserLocation = YES;
}
#end
I've been struggling with this for so long I'm tearing my hair out. Can someone point out where I've gone wrong?

Answer 1

The error message is quite self-explained.
First of all, you didn't initialized CLLocationManager in your viewDidLoad. You can initialize with (before the delegate line):
self.locationManager = [[CLLocationManager alloc] init];
Then, you have to request for location service, using [self.locationManager requestWhenInUseAuthorization] or [self.locationManager requestAlwaysAuthorization]. (Not to forget to add corresponding usage description key in Info.plist).
Last, you have to check the response of authorization from user. If user denied the authorization, you shouldn't start any Location Service-related actions, until you ask again.
Update if you support iOS 7 as well, the codes will be slightly different.