Block Method Call Example

method.m

- (void) buyFeature:(NSString*) featureId onComplete:(void (^)(NSString*)) completionBlock onCancelled:(void (^)(void)) cancelBlock;

//method call
[[MKStoreKit sharedManager] buyFeature:[product objectForKey:@"identifier"]
                            onComplete:^ (NSString *something) {
                              NSLog(@"Transaction Complete");
                            } onCancelled:^ {
                              NSLog(@"Purchase Cancelled");
                            }];