Assign NSNull Object to NSString

Question

I'm writing an iOS App where i need to get data from a SQL-Database over mobile Services from Azure.

After downloading the data I get a NSDictionary with all attributes from the SQL-Table. If an attribute is empty, the value is NSNull.

Is there a way to pass NSNull to NSString without an IF-Statement (I don't want to have 20 if statements..)?

Answer 1

I wrote a category just for dealing with this issue. I used it with Core Data but it should help you, too.

@interface NSDictionary (Extensions)

- (id)NSNullToNilForKey:(NSString *)key;

@end

@implementation NSDictionary (Extensions)

- (id)NSNullToNilForKey:(NSString *)key
{
    id value = [self valueForKey:key];

    return value != [NSNull null] ? value : nil;
}

@end

Sample use:

NSString *value = [dictionary NSNullToNilForKey:@"key"];