NSNull handling for NSManagedObject properties values

Question

I\'m setting values for properties of my NSManagedObject, these values are coming from a NSDictionary properly serialized from a JSON file. My problem

Answer 1

Ok, I've just woke up this morning with a good solution. What about this:

Serialize the JSON using the option to receive Mutable Arrays and Dictionaries:

NSMutableDictionary *rootDict = [NSJSONSerialization JSONObjectWithData:_receivedData options:NSJSONReadingMutableContainers error:&error];
...

Get a set of keys that have [NSNull null] values from the leafDict:

NSSet *nullSet = [leafDict keysOfEntriesWithOptions:NSEnumerationConcurrent passingTest:^BOOL(id key, id obj, BOOL *stop) {
    return [obj isEqual:[NSNull null]] ? YES : NO;
}];

Remove the filtered properties from your Mutable leafDict:

[leafDict removeObjectsForKeys:[nullSet allObjects]];

Now when you call fight.winnerID = [dict objectForKey:@"winner"]; winnerID is automatically going to be (null) or nil as opposed to or [NSNull null].

Not relative to this, but I also noticed that it is better to use a NSNumberFormatter when parsing strings to NSNumber, the way I was doing was getting integerValue from a nil string, this gives me an undesired NSNumber of 0, when I actually wanted it to be nil.

Before:

// when [leafDict valueForKey:@"round"] == nil
fight.round = [NSNumber numberWithInteger:[[leafDict valueForKey:@"round"] integerValue]]
// Result: fight.round = 0

After:

__autoreleasing NSNumberFormatter* numberFormatter = [[NSNumberFormatter alloc] init];
fight.round = [numberFormatter numberFromString:[leafDict valueForKey:@"round"]];    
// Result: fight.round = nil