RestKit crashing at RKEntityMapping line - ios

Question

I am new to Objective-C and very stuck with RestKit. I am trying to create a very simple UITableView with data from JSON on my web server and I have been stuck for a while.
This is my simple JSON:
{
"restaurants": [
{
"id": "27",
"franchise_name": "Franchise 1",
"branch_name": "Branch 1",
"branch_phone": "0200 111 0000",
"cuisine": "Salad",
"cooking_time": "15",
"is_open": 1
},
{
"id": "97",
"franchise_name": "Franchise 2",
"branch_name": "Branch 2",
"branch_phone": "0207 222 0000",
"cuisine": "Healthy",
"cooking_time": "10",
"is_open": 1
}
]
}
This is my Core Data model:
Entities: Restaurant
Attributes: branchName -> String
franchiseName -> String
id -> integer 16
readyTime-> integer 16
I have the following code in my view controller. In viewDidLoad, RKEntityMapping causes an exception:
RKManagedObjectStore *managedObjectStore = [RKManagedObjectStore defaultStore];
RKEntityMapping *entityMapping = [RKEntityMapping mappingForEntityForName:#"Restaurant" inManagedObjectStore:managedObjectStore]; //THIS LINE CAUSES THE CRASH
[entityMapping addAttributeMappingsFromDictionary:#{
#"id": #"id",
#"cooking_time": #"readyTime",
#"branch_name": #"branchName",
#"franchise_name": #"franchiseName"}];
RKLogConfigureByName("RestKit/Network", RKLogLevelTrace);
RKResponseDescriptor *responseDescriptor = [RKResponseDescriptor responseDescriptorWithMapping:entityMapping pathPattern:#"/api/restaurants" keyPath:nil statusCodes:RKStatusCodeIndexSetForClass(RKStatusCodeClassSuccessful)]; //I GET AN ISSUE HERE AS WELL INVOLVING responseDescriptorWithMapping BEING DEPRECIATED.
NSURLRequest *request = [NSURLRequest requestWithURL:[NSURL URLWithString:#"http//mywebserver.com/api/resturants"]];
RKManagedObjectRequestOperation *managedObjectRequestOperation = [[RKManagedObjectRequestOperation alloc] initWithRequest:request responseDescriptors:#[ responseDescriptor ]];
managedObjectRequestOperation.managedObjectContext = self.managedObjectContext;
[[NSOperationQueue currentQueue] addOperation:managedObjectRequestOperation];
There are several error messages none of which I really get:
NSAssert(objectClass, #"Cannot initialize an entity mapping for an entity with a nil managed object class: Got nil class for managed object class name '%#'. Maybe you forgot to add the class files to your target?", [entity managedObjectClassName]);
In the console:
*** Assertion failure in -[RKEntityMapping initWithEntity:],

Answer 1

responseDescriptorWithMapping is deprecated, it now has an extra method parameter. This is just a warning - you should update but you don't have to.
If the crash happens when you try to use the managedObjectStore for the first time it would suggest that you haven't properly / fully configured your Core Data stack (or that your entity name / class name is wrong). Check this doc for a simple overview of what setup is required. If you want to use an object manager, check this doc.