POST with RestKit 0.20 - NSManagedObjectContext issue - ios

Question

I'm trying to make a POST request with RestKit, but when I call the postObject method of my RKObjectManager I get the following error :
Can only use -performBlockAndWait: on an NSManagedObjectContext that was created with a queue.
This error came when the method performBlockAndWait is called by the RKManagedObjectRequestOperation class.
Here is my code :
RKObjectMapping *responseMapping = [RKObjectMapping requestMapping];
[responseMapping addAttributeMappingsFromDictionary:#{
// ...
}];
NSIndexSet *statusCodes = RKStatusCodeIndexSetForClass(RKStatusCodeClassSuccessful); // Anything in 2xx
NSString *pathPattern = #"myPath";
RKResponseDescriptor *responseDescriptor = [RKResponseDescriptor responseDescriptorWithMapping:responseMapping method:RKRequestMethodPOST pathPattern:pathPattern keyPath:nil statusCodes:statusCodes];
RKObjectMapping *requestMapping = [RKObjectMapping requestMapping];
[requestMapping addAttributeMappingsFromDictionary:#{
// ...
}];
RKRequestDescriptor *requestDescriptor = [RKRequestDescriptor requestDescriptorWithMapping:requestMapping objectClass:[MyClass class] rootKeyPath:#"" method:RKRequestMethodPOST];
NSURL *baseURL = [NSURL URLWithString:#"http://192.168.1.1:8080"];
RKObjectManager *manager = [RKObjectManager managerWithBaseURL:baseURL];
[manager addRequestDescriptor:requestDescriptor];
[manager addResponseDescriptor:responseDescriptor];
NSManagedObjectModel *managedObjectModel = [NSManagedObjectModel mergedModelFromBundles:nil];
RKManagedObjectStore *managedObjectStore = [[RKManagedObjectStore alloc] initWithManagedObjectModel:managedObjectModel];
manager.managedObjectStore = managedObjectStore;
[managedObjectStore createPersistentStoreCoordinator];
NSString *storePath = [RKApplicationDataDirectory() stringByAppendingPathComponent:#"mySqliteDatabaseFile"];
NSError *error;
NSPersistentStore *persistentStore = [managedObjectStore addSQLitePersistentStoreAtPath:storePath fromSeedDatabaseAtPath:nil withConfiguration:nil options:nil error:&error];
NSAssert(persistentStore, #"Failed to add persistent store with error: %#", error);
[managedObjectStore createManagedObjectContexts];
managedObjectStore.managedObjectCache = [[RKInMemoryManagedObjectCache alloc] initWithManagedObjectContext:managedObjectStore.persistentStoreManagedObjectContext];
// POST to create
#try {
[manager postObject:visitReport path:#"myPath" parameters:nil success:^( RKObjectRequestOperation *operation , RKMappingResult *mappingResult ) {
NSLog(#"Success");
} failure:^( RKObjectRequestOperation *operation , NSError *error ){
NSLog(#"Failure - %#",error);
}];
}
#catch (NSException *exception) {
NSLog(#"error - %#", exception);
}
I don't understand the problem with my context, any help is welcomed.
Thank you.

Answer 1

Ok finally I find the problem :
The object visitReport I tried to POST is not from the NSManagedObjectContext expected by RestKit.
To solve, I create a new object :
MyObject *visitReportContext = [NSEntityDescription insertNewObjectForEntityForName:#"tableName"
inManagedObjectContext:objectStore.mainQueueManagedObjectContext];
visitReportContext.Id = visitReport.Id
visitReportContext.title = visitReport.title
// etc..
Then, when I POST my new object, it works. But it's not very beautiful... How can I deal with my old object visitReport without create a new one in this "RestKit context" ?