Asynchronous block in a loop - objective-c

Question

How can I manage calling an asynchronous block in a loop?
My code to be called n-times:
- (void) convertToCountries:(NSString*)time longitude:(NSString*)lon latitude:(NSString*)lat {
CLLocation *myLocation = [[CLLocation alloc] initWithLatitude:[lat doubleValue] longitude:[lon doubleValue]];
[geocoder reverseGeocodeLocation:myLocation
completionHandler:^(NSArray *placemarks, NSError *error) {
NSLog(#"reverseGeocodeLocation:completionHandler: Completion Handler called!");
if (error){
NSLog(#"Geocode failed with error: %#", error);
return;
}
if(placemarks && placemarks.count > 0)
{
//do something
CLPlacemark *topResult = [placemarks objectAtIndex:0];
NSString *addressTxt = [NSString stringWithFormat:#"%#, %# %#,%# %#", [topResult country],
[topResult subThoroughfare],[topResult thoroughfare],
[topResult locality], [topResult administrativeArea]];
NSLog(#"%#",addressTxt);
NSDateFormatter *formatter = [[NSDateFormatter alloc] init];
[formatter setDateFormat:#"yyyy-MM-dd"];
//Optionally for time zone converstions
[formatter setTimeZone:[NSTimeZone timeZoneWithName:#"..."]];
[DataOperations saveRecord:[topResult country] time:time];
}
}];
}
I need to collect output data from these calls.
Any help will appreciated.

Answer 1

Give your object a property, BOOL dunloadin.
Then, in the completion block, set self.dunloadin to YES.
Finally, your loop should look something like this:
for (int i=0; i<10; i++)
{
self.dunloadin = NO;
[self convertToCountries:…];
while (!self.dunloadin)
{
[[NSRunLoop mainRunLoop] runMode:NSDefaultRunLoopMode beforeDate:[NSDate distantFuture]];
}
}
However, you might want to consider designing your app differently so that kludges like this aren't required.