Question

I am initializing a NSManagedObject subclass using:

- (void)setValuesForKeysWithDictionary:(NSDictionary *)keyedValues

I am also knowingly giving it the undefined keys, which of course should throw an exception.

So, I have implemented:

- (void)setValue:(id)value forUndefinedKey:(NSString *)key

If a key is undefined, I map it to the correct key.

However, my implementation never gets called, instead NSManagedObject‘s implementation is used, which in turn still throws an exception.

Is there a behavior (or bug) that prevents setValuesForKeysWithDictionary: from using any NSManagedObject subclass implementation of setValue:forUndefinedKey:?

Adding code as requested, but since I am just implementing an existing method, which doesn’t get called, I don’t know how much help it will be:

In the context:

- (Company*)companyWithDictionary:(NSDictionary*)values{

    Company* newCompany = (Company*)[NSEntityDescription insertNewObjectForEntityForName:@"Company" inManagedObjectContext:self];

    [newCompany setValuesForKeysWithDictionary:values];

    return newCompany;
}

In the Company subclass (never called):

- (void)setValue:(id)value forUndefinedKey:(NSString *)key{

    if([key isEqualToString:idKey]){

        [self setValue:value forKey:@"uniqueID"];

    }else if([key isEqualToString:descriptionKey]){

        [self setValue:value forKey:@"descriptionText"];

    }else if([key isEqualToString:timeUpdatedKey]){

        [self setValue:value forKey:@"dateUpdated"];

    }else{

        [super setValue:value forUndefinedKey:key];

    } 
}

Answer 1

There’s definitely nothing intrinsic to NSManagedObject that prevents this; I’m doing exactly this in the app I’m working on. Can you post more of your code?

One thought, also: are you sure it’s setValue:forUndefinedKey: that’s throwing the exception? For a managed object, I’m pretty sure you also need to implement valueForUndefinedKey: (the getter) to make things work properly.