Access newLocation from the locationManager method from other ViewController's

Question

I'm using CoreLocation and am starting the locationManager from within my applications AppDelegate. Example Code below...

AppDelegate.m

- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions
{
    // ...

    // start location manager
    if([CLLocationManager locationServicesEnabled])
    {
        myLocationManager_ = [[CLLocationManager alloc] init];
        myLocationManager_.delegate = self;
        [myLocationManager_ startUpdatingLocation];
    }
    else 
    {
        // ... rest of code snipped to keep this short

And in this method we see the updated location.

-(void)locationManager:(CLLocationManager *)manager didUpdateToLocation:(CLLocation *)newLocation fromLocation:(CLLocation *)oldLocation
{
    NSString *currentLatitude = [[NSString alloc] initWithFormat:@"%g", newLocation.coordinate.latitude];
    NSLog(@"AppDelegate says: latitude: %@", currentLatitude);

    // ... rest of code snipped

Now, within other areas of my application I need to determine the users current location (latitude, longitude). I could incorporate the code above into the ViewControllers that need current location but then I would have multiple instances of CLLocationManager running (I think) - and why duplicate this code?? Isn't there a way that, from other ViewControllers, I can just grab the location information from the AppDelegate?

PS - I'm using Xcode 4.3 w/ ARC

Answer 1

To do this, declare the variable as a property in your appDelegate:

@property (nonatomic, retain) NSArray *array;

(@synthesize in your .m too)

Then in your view controllers, create an appDelegate variable:

AppDelegate *appDelegate=(AppDelegate*)[[UIApplication sharedApplication] delegate];

then you can do: NSLog(@"%@", appDelegate.array);