Integrating GPS to my application - iphone

Question

I am following a tutorial to integrate GPS to my application. I want to display the Latitude and Longitude values in the viewDidLoad method. According to the tutorial they have displayed it from another method. But i need it to be displayed in viewDidLoad. How can i modify the following code to display it in viewDidLoad ?
The HelloThereController.h view controller
#import "MyCLController.h"
#interface HelloThereViewController : UIViewController <MyCLControllerDelegate> {
MyCLController *locationController;
}
- (void)locationUpdate:(CLLocation *)location;
- (void)locationError:(NSError *)error;
#end
The HelloThereController.m view controller
#import "HelloThereViewController.h"
#implementation HelloThereViewController
- (void)viewDidLoad {
locationController = [[MyCLController alloc] init];
locationController.delegate = self;
[locationController.locationManager startUpdatingLocation];
//I need to print the latitude and logitude values here..
}
My MyCLController.h class
#protocol MyCLControllerDelegate
#required
- (void)locationUpdate:(CLLocation *)location;
- (void)locationError:(NSError *)error;
#end
#interface MyCLController : NSObject {
CLLocationManager *locationManager;
id delegate;
}
#property (nonatomic, retain) CLLocationManager *locationManager;
#property (nonatomic, assign) id delegate;
- (void)locationManager:(CLLocationManager *)manager
didUpdateToLocation:(CLLocation *)newLocation
fromLocation:(CLLocation *)oldLocation;
- (void)locationManager:(CLLocationManager *)manager
didFailWithError:(NSError *)error;
#end
My MyCLController.m class
#import "MyCLController.h"
#implementation MyCLController
#synthesize locationManager;
#synthesize delegate;
- (id) init {
self = [super init];
if (self != nil) {
self.locationManager = [[[CLLocationManager alloc] init] autorelease];
self.locationManager.delegate = self;
}
return self;
}
- (void)locationManager:(CLLocationManager *)manager
didUpdateToLocation:(CLLocation *)newLocation
fromLocation:(CLLocation *)oldLocation
{
[self.delegate locationUpdate:newLocation];
}
- (void)locationManager:(CLLocationManager *)manager
didFailWithError:(NSError *)error
{
[self.delegate locationError:error];
}
- (void)dealloc {
[self.locationManager release];
[super dealloc];
}
#end

Answer 1

If this view controller loads as soon as the app loads, you can't.
it takes time for the location manager to get gps updates.
you'll need to display some ui component that lets the user know you're getting the location, such as UIActivityIndicatorView, and setup another method for displaying the coordinates when you get them.

Answer 2

In general you can accelerate the process sacrificing some accuracy setting the desiredAccuracy property. According to the documentation the values are:
kCLLocationAccuracyBestForNavigation
kCLLocationAccuracyBest
kCLLocationAccuracyNearestTenMeters
kCLLocationAccuracyHundredMeters
kCLLocationAccuracyKilometer
kCLLocationAccuracyThreeKilometers
Anyway you are interested in the first location, so still according to the documentation:
When requesting high-accuracy location data, the initial event delivered by the location
service may not have the accuracy you requested. The location service delivers the initial
event as quickly as possible. It then continues to determine the location with the accuracy
you requested and delivers additional events, as necessary, when that data is available.
You can try starting the location manager in the AppDelegate didFinishLaunchingWithOptions to have some more time before the view appears. As said by Frederick Cheung, locationManager.location can be nil, so it's better do the operations in the location manager delegate.