Method orders in viewDidLoad - ios

Question

I have methods in viewDidLoad, and it seems like the order of methods getting called is weird.
- (void)viewDidLoad
{
[super viewDidLoad];
// Get Location
self.locationManager = [[CLLocationManager alloc] init];
self.geocoder = [[CLGeocoder alloc] init];
self.locationManager.delegate = self;
self.locationManager.desiredAccuracy = kCLLocationAccuracyBest;
if([self.locationManager respondsToSelector:#selector(requestWhenInUseAuthorization)])
{
[self.locationManager requestWhenInUseAuthorization];
}
[self.locationManager startUpdatingLocation];
// Retrieve Data
[self retrieveData];
}
After viewDidLoad is called, it calls the retrieveData method before locationManager.
Shouldn't the locationManager be called before retrieveData because of the order?
I am new in Objective C, thank you for your help in advance.

Answer 1

as per your need call your method in inside the delegate methods, so remove the [self retrieveData]; from ViewDidLoad and add into inside the didFailWithError or didUpdateLocations methods.
- (void)viewDidLoad
{
[super viewDidLoad];
// Get Location
self.locationManager = [[CLLocationManager alloc] init];
self.geocoder = [[CLGeocoder alloc] init];
self.locationManager.delegate = self;
self.locationManager.desiredAccuracy = kCLLocationAccuracyBest;
if([self.locationManager respondsToSelector:#selector(requestWhenInUseAuthorization)])
{
[self.locationManager requestWhenInUseAuthorization];
}
[self.locationManager startUpdatingLocation];
}
- (void)locationManager:(CLLocationManager *)manager didFailWithError:(NSError *)error
{
UIAlertView *errorAlert = [[UIAlertView alloc]
initWithTitle:#"Error"
message:#"Failed to Get Your Location"
delegate:nil
cancelButtonTitle:#"OK"
otherButtonTitles:nil];
[errorAlert show];
// call here
[self retrieveData];
}
- (void)locationManager:(CLLocationManager *)manager didUpdateLocations:(NSArray *)locations
{
// set or stop your location update
manager = nil;
[self.locationManager stopUpdatingLocation];
[manager stopUpdatingLocation];
CLLocation *newLocation = locations[[locations count] -1];
CLLocation *currentLocation = newLocation;
NSString *longitude = [NSString stringWithFormat:#"%.8f", currentLocation.coordinate.longitude];
NSString *latitude = [NSString stringWithFormat:#"%.8f", currentLocation.coordinate.latitude];
if (currentLocation != nil) {
NSLog(#"latitude: %#", latitude);
NSLog(#"longitude: #"%#", longitude);
}else {
UIAlertView *errorAlert = [[UIAlertView alloc]
initWithTitle:#"Error" message:#"Failed to Get Your Location"
delegate:nil
cancelButtonTitle:#"OK"
otherButtonTitles:nil];
[errorAlert show];
}
// call here
[self retrieveData];
}
Note
objective -C is the interpreter , it execute the every in step by step , so or may be your [self retrieveData]; is called in main thread, that is the reason it execute in prior.