IPhone : Download data from JSON and store to CoreData and Display in the same time when data downloads in background

I am parsing data from JSON and Storing to CoreData in the same time i am displaying the the data to tableview but the problem i am having is data is displaying only after download completed but i dont want like this i want to download the data in background and display the data while downloading is processed also how can i do this

-(void)connectionDidFinishLoading:(NSURLConnection *)connection
{
    [UIApplication sharedApplication].networkActivityIndicatorVisible = NO;
    arrayData = [NSJSONSerialization JSONObjectWithData:data options:0 error:nil];
    NSError *error;
    NSManagedObjectContext *context = [appDelegate managedObjectContext];
    context = [appDelegate managedObjectContext];

    for (int i = 0; i < [arrayData count]; i++) {

        idNum = [arrayData objectAtIndex:i][@"id"];
        NSFetchRequest *request = [NSFetchRequest fetchRequestWithEntityName:@"Discount"];
        [request setPredicate:[NSPredicate predicateWithFormat:@"cID = %@",idNum]];
        [request setFetchLimit:1];
        NSUInteger count = [context countForFetchRequest:request error:&error];
        if (count == NSNotFound) {
            NSLog(@"ERROR");
        }else if (count == 0) {
            NSLog(@"New Data Coming");

            name  = [arrayData objectAtIndex:i][@"name"];
            summary = [arrayData objectAtIndex:i][@"summary"];
            region = [arrayData objectAtIndex:i][@"region"];
            imageURL = [arrayData objectAtIndex:i][@"images"][@"logo"];

            id  benefits1 = [arrayData objectAtIndex:i][@"benefits"];
            benefiteString = [NSString stringWithFormat:@"%@ %@",[benefits1 objectAtIndex:0][@"key"],[benefits1 objectAtIndex:0][@"value"]];
            NSData * data = [NSData dataWithContentsOfURL:[NSURL URLWithString:imageURL]];
            dateUpdate = [arrayData objectAtIndex:i][@"updated_at"];
            NSDateFormatter *dateFormatter = [[NSDateFormatter alloc]init];
            [dateFormatter setDateFormat: @"yyyy-MM-dd'T'HH:mm:ss.sssZ"];
            NSDate *date =[dateFormatter dateFromString:dateUpdate];
            [dateFormatter setDateFormat:@"yyyy/MM/dd HH:mm:ss"];
            NSLog(@"DAte : %@",date);
            Discount * d = [NSEntityDescription insertNewObjectForEntityForName:@"Discount" inManagedObjectContext:context];
            d.name = name;
            d.summary = summary;
            d.regions = region;
            d.cID = idNum;
            d.imageLogo = data;
            d.updated_at = date;
            d.benefits = benefiteString;
            if (![context save:&error]) {
                NSLog(@"Getting error while saving data");
            }
            else{
                NSLog(@"Saved");
            }
        }

    }
    [sharedAppDelegate dismissGlobalHUD];
    [listTableView reloadData];
}

-(NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section
{
    return [_myArray count];
}
-(UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
    customCellClass = [tableView dequeueReusableCellWithIdentifier:@"Cell"];
    if (customCellClass == nil)
    {
        customCellClass = [[CellCustom alloc]initWithStyle:UITableViewCellStyleDefault reuseIdentifier:@"Cell"];
    }
    customCellClass.nameLabel.text = [[_myArray objectAtIndex:indexPath.row]name];
    customCellClass.cityLabel.text =[[_myArray objectAtIndex:indexPath.row]regions];
    customCellClass.detailLabel.text = [[_myArray objectAtIndex:indexPath.row]summary];

    NSData * d = [[_myArray objectAtIndex:indexPath.row]imageLogo];
    customCellClass.mainImage.image = [UIImage imageWithData:d];

    customCellClass.benefitsLabel.text = [[_myArray objectAtIndex:indexPath.row]benefits];
    [sharedAppDelegate dismissGlobalHUD];
    return customCellClass;
}

-(void)dataDidSave
{

    NSManagedObjectContext *context = [appDelegate managedObjectContext];
    NSFetchRequest *fetchRequest = [[NSFetchRequest alloc] init];
    NSEntityDescription *entity = [NSEntityDescription entityForName:@"Discount" inManagedObjectContext:context]; [fetchRequest setEntity:entity];
    [fetchRequest setEntity:entity];
    NSError *error = nil;
    NSArray *result = [context executeFetchRequest:fetchRequest error:&error];

    self.myArray = result;
    [listTableView reloadData];
}
-(void)viewWillAppear:(BOOL)animated
{
    [sharedAppDelegate showGlobalProgressHUDWithTitle:@"Loading..."];
    [self dataDidSave];
}