I am currently trying to store images I download from the web into an NSManagedObject class so that I don't have to redownload it every single time the application is opened. I currently have these two classes.

Plant.h

@property (nonatomic, retain) NSString * name;
@property (nonatomic, retain) PlantPicture *picture;

PlantPicture.h

@property (nonatomic, retain) NSString * bucketName;
@property (nonatomic, retain) NSString * creationDate;
@property (nonatomic, retain) NSData * pictureData;
@property (nonatomic, retain) NSString * slug;
@property (nonatomic, retain) NSString * urlWithBucket;

Now I do the following:

- (UICollectionViewCell *)collectionView:(UICollectionView *)collectionView cellForItemAtIndexPath:(NSIndexPath *)indexPath
{
    PlantCollectionCell *cell = [collectionView dequeueReusableCellWithReuseIdentifier:CellIdentifier forIndexPath:indexPath];
    Plant *plant = [self.fetchedResultsController objectAtIndexPath:indexPath];

    cell.plantLabel.text = plant.name;

    if(plant.picture.pictureData == nil)
    {
        NSLog(@"Downloading");
        NSMutableString *pictureUrl = [[NSMutableString alloc]initWithString:amazonS3BaseURL];
        [pictureUrl appendString:plant.picture.urlWithBucket];
        NSURLRequest *request = [NSURLRequest requestWithURL:[NSURL URLWithString:pictureUrl]];        

        AFImageRequestOperation *imageOperation = [AFImageRequestOperation imageRequestOperationWithRequest:request success:^(UIImage *image) {
            cell.plantImageView.image = image;
            plant.picture.pictureData = [[NSData alloc]initWithData:UIImageJPEGRepresentation(image, 1.0)];
            NSError *error = nil;
            if (![_managedObjectContext save:&error]) {
                NSLog(@"Unresolved error %@, %@", error, [error userInfo]);
            }
        }];
        [imageOperation start];
    }
    else
    {
        NSLog(@"Already");
        cell.plantImageView.image = [UIImage imageWithData:plant.picture.pictureData];
    }
    NSLog(@"%@", plant.name);
    return cell;
}

The plant information is present, as well as the picture object. However, the NSData itself is NEVER saved throughout the application opening and closing. I always have to REDOWNLOAD the image! Any ideas!? [Very new to CoreData... sorry if it is easy!]

thanks!