CLGeocoder only working 50% of the time - ios

Question

so I'm trying to search a location using CLGeocoder,
It works the first time I do it, but it's very unreliable. Sometimes it will work, when I go back, try it again. crashes. Sometimes when I load it I get an error PBRequester failed with Error Error Domain=NSURLErrorDomain, then something with the span.
This is my code:
CLGeocoder *geocoder = [[CLGeocoder alloc] init];
[geocoder geocodeAddressString:placeName completionHandler:^(NSArray *placemarks, NSError *error) {
//Error checking
CLPlacemark *placemark = [placemarks objectAtIndex:0];
MKCoordinateRegion region;
region.center = [(CLCircularRegion *)placemark.region center];
region.center.latitude = placemark.region.center.latitude;
region.center.longitude = placemark.region.center.longitude;
MKCoordinateSpan span;
double radius = placemark.region.radius / 1000; // convert to km
NSLog(#"Radius is %f", radius);
span.latitudeDelta = radius / 112.0;
region.span = span;
[self.mapView setRegion:region animated:YES];
}];

Answer 1

During geocoding a lot of things can happen. Since it is an internet service its functionality is based on internet reachability and available band.
Fortunately the CLGeocoder returns and error in the completion block, it is supposed that if an error happen you must handle correctly. If your app crashes is not a geocoded fault, because probably you are not handling well the error or the situation.
CLGeocoder *geocoder = [[CLGeocoder alloc] init];
[geocoder geocodeAddressString:placeName completionHandler:^(NSArray *placemarks, NSError *error) {
/* Error checking */
if (error)
{
NSLog(#"The error is %#",error.localizedDescription);
return;
}
if (placemarks.count >1)
{
/* Handle multiple placemarks */
}
else {
/* This is probably the source of your crashes if there is an error placemarks it would be an empty array, but if you ask for an object it will raise an exception for out-of-bounds index */
CLPlacemark *placemark = [placemarks objectAtIndex:0];
MKCoordinateRegion region;
region.center = [(CLCircularRegion *)placemark.region center];
region.center.latitude = placemark.region.center.latitude;
region.center.longitude = placemark.region.center.longitude;
MKCoordinateSpan span;
double radius = placemark.region.radius / 1000; /* convert to km */
NSLog(#"Radius is %f", radius);
span.latitudeDelta = radius / 112.0;
region.span = span;
[self.mapView setRegion:region animated:YES];
}
}];
Some suggestion:
Handle the error
Check how many placemarks the geocoded have be returned, they can be more than one
In your code if the geocoded will return an empty array, asking for an object at index 0 will raise an out-of-bounds exception, always check if the count is different from 0 or use -firstObject method (iOS7 only)