Question

I have a JSON response that I turn into a Dictionary like so:

NSError *error;
self.restKitResponseDict = [NSDictionary dictionaryWithDictionary:[NSJSONSerialization JSONObjectWithData:response.body options:0 error:&error]];

I have a core data class that has the following attributes/properties:

name
image_url

When I log the restKitResponseDict from above I see that image_url is listed as "image_url" like this:

name = Rock;
"image_url" = "http://f.cl.ly/items/122s3f1M1E1p432B211Q/catstronaut.jpg";

Is this why KVC is crashing on

[CoreDataClass setValuesForKeysWithDictionary:self.restKitResponseDict];

like this:

'[<CoreDataClass 0x14132c> setValue:forUndefinedKey:]: this class is not key value coding-compliant for the key image_url.'

Do the quotes matter? Should I ask my server guy to get rid of the underscore that’s likely causing it?

Core Data Class:

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

@interface CoreDataClass : NSManagedObject

@property (nonatomic, retain) NSString * name;
@property (nonatomic, retain) NSString * image_url;

@end

@implementation CoreDataClass

@dynamic name;
@dynamic image_url;

@end

Answer 1

You are sending the method to the class object:

[CoreDataClass setValuesForKeysWithDictionary:self.restKitResponseDict];

when you probably want to send it to the actual CoreDataClass instance:

[coreDataClassObject setValuesForKeysWithDictionary:self.restKitResponseDict];

EDIT

what’s the simplest way to init the object from the class? – Eric

It’s a subclass of NSManagedObject, so you use the normal Core Data methods. One way to create a new object:

CoreDataClass *coreDataObject = [NSEntityDescription
    insertNewObjectForEntityForName:@"YOUR_ENTITY_NAME"
    inManagedObjectContext:managedObjectContext];

If you need basic information about using Core Data, see the Core Data Programming Guide: http://developer.apple.com/library/ios/#documentation/cocoa/conceptual/coredata/cdProgrammingGuide.html#//apple_ref/doc/uid/TP30001200-SW1