Allows you to selectively ignore undefined keys when setting a value by key.

CPObject+CPCodingExtensions.j

@implementation CPObject (CPCodingExtensions)

- (void)setValue:(id)aValue forKey:(CPString)aKey ignoreUndefinedKey:(BOOL)ignoreUndefinedKey
{
  if (!ignoreUndefinedKey)
  {
    [self setValue:aValue forKey:aKey];
  }
  else
  {
    try { [self setValue:aValue forKey:aKey]; }
    catch (e)
    {
      if (!e.isa || ![e isKindOfClass:[CPException class]] || // a non-ObjJ error object
          [e name] != CPUndefinedKeyException ||
         [[e userInfo] objectForKey:CPTargetObjectUserInfoKey] != self ||
         [[e userInfo] objectForKey:CPUnknownUserInfoKey] != aKey)
        // this exception wasn't triggered because we don't have the property,
        // but for some other reason, so we should pass it along
        throw e;
    }
  }
}

@end