objective c - iPhone - Get City name from Latitude and Longtiude

Question

I want get my Current City name in my iPhone App.

I'm currently getting the latitude and longitude using CLLocationManager and than i am passing my coordinates into CLGeocoder.

    CLGeocoder * geoCoder = [[CLGeocoder alloc] init];
    [geoCoder reverseGeocodeLocation:location completionHandler:^(NSArray *placemarks, NSError *error) {
        for (CLPlacemark * placemark in placemarks) {
            UIAlertView *alert = [[UIAlertView alloc] initWithTitle:@"Current City" message:[NSString stringWithFormat:@"Your Current City:%@",[placemark locality]] delegate:self cancelButtonTitle:@"OK" otherButtonTitles:@"Cancel", nil];
            [alert  show];
        }  
    }];

This is working fine in iOS 5.0 but not working in iOS 4.3.

As an alternative, I started using the Google Web service

-(void)findLocationFor:(NSString *)latitudeStr 
          andLontitude:(NSString *)longtitudeStr{
    if ([self connectedToWiFi]){
        float latitude  = [latitudeStr floatValue];
        float longitude = [longtitudeStr floatValue];
        NSMutableDictionary *parameters = [NSMutableDictionary dictionaryWithObjectsAndKeys: 
                                           [NSString stringWithFormat:@"%f,%f", latitude, longitude], @"latlng", nil];
        NSMutableURLRequest *request = [NSMutableURLRequest requestWithURL:[NSURL URLWithString:@"http://maps.googleapis.com/maps/api/geocode/json"]];
        [parameters setValue:@"true" forKey:@"sensor"];
        [parameters setValue:[[NSLocale currentLocale] objectForKey:NSLocaleLanguageCode] forKey:@"language"];
        NSMutableArray *paramStringsArray = [NSMutableArray arrayWithCapacity:[[parameters allKeys] count]];

        for(NSString *key in [parameters allKeys]) {
            NSObject *paramValue = [parameters valueForKey:key];
            [paramStringsArray addObject:[NSString stringWithFormat:@"%@=%@", key, paramValue]];
        }

        NSString *paramsString = [paramStringsArray componentsJoinedByString:@"&"];
        NSString *baseAddress = request.URL.absoluteString;
        baseAddress = [baseAddress stringByAppendingFormat:@"?%@", paramsString];
        [request setURL:[NSURL URLWithString:baseAddress]];

        NSError        *error    = nil;
        NSURLResponse  *response = nil;
        NSData *returnData = [NSURLConnection sendSynchronousRequest:request returningResponse:&response error:&error];
        if (response == nil) {
            if (error != nil) {
            }
        }
        else {
            NSDictionary *responseDict = [returnData objectFromJSONData];
            NSArray *resultsArray = [responseDict valueForKey:@"results"]; 
            NSMutableArray *placemarksArray = [NSMutableArray arrayWithCapacity:[resultsArray count]];
            for(NSDictionary *placemarkDict in resultsArray){
                NSDictionary *coordinateDict = [[placemarkDict valueForKey:@"geometry"] valueForKey:@"location"];

                float lat = [[coordinateDict valueForKey:@"lat"] floatValue];
                float lng = [[coordinateDict valueForKey:@"lng"] floatValue];

                NSMutableDictionary *dict = [[NSMutableDictionary alloc] init];
                [dict setObject:[NSString stringWithFormat:@"%.f",lat] forKey:@"latitude"];
                [dict setObject:[NSString stringWithFormat:@"%.f",lng] forKey:@"longitude"];
                [dict setObject:[placemarkDict objectForKey:@"formatted_address"] forKey:@"address"];

                [placemarksArray addObject:dict];
                [dict release];
            }
            NSDictionary *placemark = [placemarksArray objectAtIndex:0];
        }
    }
}

But the response which i am getting is too long , means i am still unable to get the city name because in some case this web service give all other information regarding coordinates expect City Name.

Can any one help me please?

Answer 1

As per documentation CLGeocoder does not work below iOS5. You need to take another route to support iOS4 and iOS5 both.

You can look at MKReverseGeocoder, however it is deprecated in iOS5 but still will serve the purpose. For confirmation you can check so called question

+(NSString *)getAddressFromLatLon:(double)pdblLatitude withLongitude:(double)pdblLongitude
{
    NSString *urlString = [NSString stringWithFormat:@"http://maps.google.com/maps/geo?q=%f,%f&output=csv",pdblLatitude, pdblLongitude];
    NSError* error;
    NSString *locationString = [NSString stringWithContentsOfURL:[NSURL URLWithString:urlString] encoding:NSASCIIStringEncoding error:&error];
    locationString = [locationString stringByReplacingOccurrencesOfString:@""" withString:@""];
    return [locationString substringFromIndex:6];
}

You can use this function for getting address from latitude, longitude. You can change according to requirement. We put this as Class method so we can directly use it as

NSString *strAddressFromLatLong = [CLassName getAddressFromLatLon:37.484848 withLongitude:74.48489];

EDIT

Please stop using above function as it has stopped working reported in comments (Not tested by me). I recommend to start using SVGeocoder