Question

My main problem is storing the data which is not supported by Core Data. I already have a CLLocation property stored as a transformable attribute. I think the right approach is to declare a transient coordinate property. I keep getting EXC_BAD_ACCESS errors however.

EDIT:

My current subclass has the following interface:

#import <Foundation/Foundation.h>
#import <CoreLocation/CoreLocation.h>

@interface Event : NSManagedObject {

}

@property (nonatomic, retain) NSString* title;
@property (nonatomic, retain) NSDate* timeStamp;
@property (nonatomic, retain) CLLocation *location;

@end

So I need to add

@property (nonatomic, readonly) CLLocationCoordinate2D coordinate;

and

- (void)setCoordinate:(CLLocationCoordinate2D)newCoordinate;

to conform to the protocol. (setCoordinate is optional, but I need it if I want to have the annotation draggable)

In core data, The location property is transformable. and I use @dynamic in the implementation to generate the accessors. I’m using this property throughout the code, so I don’t want to keep this.

I think the best way to go about it is to define my coordinate property in core data as transient, but I am not definitely doing something wrong with the implementation.

- (CLLocationCoordinate2D)coordinate {
    CLLocationCoordinate2D cor = CLLocationCoordinate2DMake(self.location.coordinate.latitude,
    self.location.coordinate.longitude);
    return cor;
}

- (void)setCoordinate:(CLLocationCoordinate2D)newCoordinate {
    CLLocation *newLoc = [[CLLocation alloc] initWithLatitude:newCoordinate.latitude
    longitude:newCoordinate.longitude];
    [self.location release];
    self.location = newLoc;
} 

I’ve tried several ways, but this is the most recent one.

Edit 2:
The EXC_BAD_ACCESS in:

_kvcPropertysPrimitiveSetters

Answer 1

You can make a NSManagedObject subclass conform to whatever protocol you wish as long as the protocol doesn’t somehow override the context’s management of the instances. MKAnnotation protocol should be perfectly safe.

Update:

Your problem is most likely here:

- (void)setCoordinate:(CLLocationCoordinate2D)newCoordinate {
    CLLocation *newLoc = [[CLLocation alloc] initWithLatitude:newCoordinate.latitude
                                                    longitude:newCoordinate.longitude];
    [self.location release]; //<-- Don't release properties!
    self.location = newLoc;
}

The generator accessors will handle retention for you. When you release them directly you screw that management up. You’re also leaking newLoc. Try:

- (void)setCoordinate:(CLLocationCoordinate2D)newCoordinate {
    CLLocation *newLoc = [[CLLocation alloc] initWithLatitude:newCoordinate.latitude
                                                    longitude:newCoordinate.longitude];
    self.location = newLoc;
    [newLoc release];
}