iPhone: Save boolean into Core Data

Question

I have set up one of my core data attributes as a Boolean. Now, I need to set it, but XCode keeps telling me that it may not respond to setUseGPS.

[ride setUseGPS: useGPS.on];

What is the method for setting a boolean in core data? All my other attributes are set this way, and they work great. So, not sure why a boolean does not work to be set this way?

Answer 1

Core Data "does not have" a Boolean type (it does, but it is an NSNumber).

So to set the equivalent of useGPS = YES.

[entity setUseGPS:[NSNumber numberWithBool:YES]];

And the other way around:

BOOL isGPSOn = [[entity useGPS] boolValue];

Answer 2

The "fix" for this (IMHO, it's a bug in Apple's SDK) is to add the following code to your CoreData-generated class. NB: if you do this in a category, in a separate file, then you don't have to re-copy/paste it each time you regenerate the CoreData classes inside Xcode

- (BOOL)useGPS
{
    [self willAccessValueForKey:@"useGPS"];
    BOOL myuseGPS = [[self primitiveUseGPS] boolValue];
    [self didAccessValueForKey:@"useGPS"];
    return myuseGPS;
}

- (void)setUseGPS:(BOOL)newValue
{
    [self willChangeValueForKey:@"useGPS"];
    [self setPrimitiveUseGPS:[NSNumber numberWithBool:newValue]];
    [self didChangeValueForKey:@"useGPS"];
}

Answer 3

@RickiG thanks for the answer.. cannot vote you up (new member sorry) but it helped me a lot...