Objective-C issues with dataTaskWithRequest - ios

Question

I have recently switched from sendSynchronousRequest to dataTaskWithRequest
with sendSynchronousRequest my method was working perfectly but when I switch to dataTaskWithRequest I get the following error:
error NSURLError * domain: #"NSURLErrorDomain" - code: 4294966096 0x15ee96c0
and
myError NSError * domain: nil - code: 1684370017 0x26cce125
I don't understand why.
Here is the old code (commented out) and the new code:
/*-(NSDictionary *)GetProductionScheduleData:(NSString *)areaDescription
{
NSString *areaDescriptionWSpaceCharacters = [areaDescription stringByReplacingOccurrencesOfString:#" " withString:#"%20"];
NSString *requestString = [NSString stringWithFormat:#"%#?areaDescription=%#",kIP,areaDescriptionWSpaceCharacters];
NSURL *JSONURL = [NSURL URLWithString:requestString];
NSURLResponse* response = nil;
NSMutableURLRequest *request = [NSMutableURLRequest requestWithURL:JSONURL];
NSData* data = [NSURLConnection sendSynchronousRequest:request returningResponse:&response error:nil];
if(data == nil)
return nil;
NSError *myError;
NSDictionary *productionSchedule = [[NSDictionary alloc]initWithDictionary:[NSJSONSerialization JSONObjectWithData:data options:kNilOptions error:&myError]];
return productionSchedule;
}*/
-(void)GetProductionScheduleData:(NSString *)areaDescription Completetion:(void (^) (NSMutableDictionary * result,NSError * error))completion{
NSString *areaDescriptionWSpaceCharacters = [areaDescription stringByReplacingOccurrencesOfString:#" " withString:#"%20"];
NSString *requestString = [NSString stringWithFormat:#"%#?areaDescription=%#",kIP,areaDescriptionWSpaceCharacters];
NSURL *JSONURL = [NSURL URLWithString:requestString];
NSMutableURLRequest *request = [NSMutableURLRequest requestWithURL:JSONURL];
NSURLSession *session = [NSURLSession sharedSession];
NSURLSessionDataTask *dataTask = [session dataTaskWithRequest:request
completionHandler:^(NSData *data, NSURLResponse *response, NSError *error)
{
NSError *myError;
NSMutableDictionary *productionSchedule = [[NSMutableDictionary alloc]initWithDictionary:[NSJSONSerialization JSONObjectWithData:data options:kNilOptions error:&myError]];
completion(productionSchedule,myError);
}];
[dataTask resume];
}
Please Help! This was working with sendSynchronousRequest I am starting to dislike dataTaskWithRequest.

Answer 1

The NSURLSession code you have is correct, I confirmed with a valid URL.
You stopped checking to see if data is nil before attempting to JSON parse it. If you add that check back I bet you'll find that there is an error and data is in fact nil.
Change to:
NSURLSessionDataTask *dataTask = [session dataTaskWithRequest:request completionHandler:^(NSData *data, NSURLResponse *response, NSError *error) {
// handle request error
if (error) {
completion(nil, error);
return;
}
NSError *myError;
NSMutableDictionary *productionSchedule = [[NSMutableDictionary alloc]initWithDictionary:[NSJSONSerialization JSONObjectWithData:data options:kNilOptions error:&myError]];
completion(productionSchedule,myError);
}];
I would recommend also checking myError before attempting to set it to productionSchedule (which could also cause a crash).