Question

When I updated Xcode to 4.4.1 It gives me 22 warning for using RestKit Library. The error was like this:

Direct access to objective-c's isa is deprecated in favor of object_setClass() and object_getClass()

I fixed 18 warnings by replacing:

Replace %lu with %u

Replace object->isa with object_getClass(object)

Replace keyObject->isa with object_getClass(keyObject)

There are 4 more warnings that I cannot fix it, here are the warnings following by its descriptions:

file Name 1: RKManagedObjectMappingOperation.m
Warning Line1:

NSAssert(mapping, @"Attempted to connect relationship for keyPath '%@' without a relationship mapping defined.");

Warning Description1:

more '%' conversations than data arguments

File Name2: RKReachabilityObserver.m
Warning Line2:

return [NSString stringWithFormat:@"<%@: %p host=%@ isReachabilityDetermined=%@ isMonitoringLocalWiFi=%d reachabilityFlags=%@>",
            NSStringFromClass([self class]), self, self.host, self.isReachabilityDetermined ? @"YES" : @"NO",
            self.isMonitoringLocalWiFi ? @"YES" : @"NO", [self reachabilityFlagsDescription]];

Warning description2:

format specifies type int but the argument has type NSString

File Name3: JSONKit.m
Warning Line3:

if(JK_EXPECT_F(((id)keys[idx])->isa != encodeState->fastClassLookup.stringClass) && JK_EXPECT_F([(id)keys[idx] isKindOfClass:[NSString class]] == NO)) { jk_encode_error(encodeState, @"Key must be a string object."); return(1); }

Warning Description3:

Direct access to objective-c's isa is deprecated in favor of object_setClass() and object_getClass()

File Name4: NSManagedObject+ActiveRecord.m
Warning Line 4:

RKLogError(@"Property '%@' not found in %@ properties for %@", propertyName, [propDict count], NSStringFromClass(self));

Warning description4:

format specifies type id but the argument has type NSUInteger

How to fix it?

Answer 1

Warning 1:

NSAssert(mapping, @"Attempted to connect relationship for keyPath '%@' without a relationship mapping defined.");

becomes

NSAssert(mapping, @"Attempted to connect relationship for keyPath '%@' without a relationship mapping defined.", <<put the corresponding keyPath here >> );

or

NSAssert(mapping, @"Attempted to connect relationship for a keyPath without a relationship mapping defined.");

it said “more ‘%’ conversations than data arguments” meaning that you have placeholders, in this case %@, but no arguments to fill them. So either provide an argument or delete the placeholder.

Warning 2:

return [NSString stringWithFormat:@"<%@: %p host=%@ isReachabilityDetermined=%@ isMonitoringLocalWiFi=%d reachabilityFlags=%@>",
        NSStringFromClass([self class]), self, self.host, self.isReachabilityDetermined ? @"YES" : @"NO",
        self.isMonitoringLocalWiFi ? @"YES" : @"NO", [self reachabilityFlagsDescription]];

becomes

return [NSString stringWithFormat:@"<%@: %p host=%@ isReachabilityDetermined=%@ isMonitoringLocalWiFi=%@ reachabilityFlags=%@>",
        NSStringFromClass([self class]), self, self.host, self.isReachabilityDetermined ? @"YES" : @"NO",
        self.isMonitoringLocalWiFi ? @"YES" : @"NO", [self reachabilityFlagsDescription]];

notice the isMonitoringLocalWiFi=%d part gets %@ instead of %d, because you provide a string argument but have an integer placeholder.

Warning 3: Sorry can’t help you with this one. Probably after I take a look at the code I’ll post an update.

update: try changing

((id)keys[idx])->isa

to

object_getClass( ((id)keys[idx]) )

Warning 4:

RKLogError(@"Property '%@' not found in %@ properties for %@", propertyName, [propDict count], NSStringFromClass(self));

becomes

RKLogError(@"Property '%@' not found in %d properties for %@", propertyName, [propDict count], NSStringFromClass(self));

notice the second placeholder should be %d and not %@ since you provide an integer or in this case a NSUInteger, i.e. [propDict count] argument.