RestKit Foreign Key Connections to-many and to-one - ios

Question

My goal is to implement one-to-many and many-to-one relationship connection with RestKit. I'm using version 0.20pre6.
This page http://restkit.org/api/0.20.0/Classes/RKConnectionDescription.html#overview reports half example.
First example is many-to-one.
json:
{ "project":
{ "id": 12345,
"name": "My Project",
"userID": 1
}
}
code:
NSEntityDescription *projectEntity = [NSEntityDescription entityForName:#"Project" inManagedObjectContext:managedObjectContext];
NSRelationshipDescription *userRelationship = [projectEntity relationshipsByName][#"user"];
RKConnectionDescription *connection = [[RKConnectionDescription alloc] initWithRelationship:userRelationship attributes:#{ #"userID": #"userID" }];
The thing i missed during my first attempt is that userID needs to be in the Entity too. Otherwise it won't work. I don't really understand why... anyway it works.
My problem is related to the second example which is a one-to-many. Json example:
{ "project":
{ "id": 12345,
"name": "My Project",
"userID": 1,
"teamMemberIDs": [1, 2, 3, 4]
}
}
code:
NSEntityDescription *projectEntity = [NSEntityDescription entityForName:#"Project" inManagedObjectContext:managedObjectContext];
NSRelationshipDescription *teamMembers = [projectEntity relationshipsByName][#"teamMembers"]; // To many relationship for the `User` entity
RKConnectionDescription *connection = [[RKConnectionDescription alloc] initWithRelationship:teamMembers attributes:#{ #"teamMemberIDs": #"userID" }];
Now... teamMemberIDs needs to be in the Entity definition just like userID in the previous example. Here are my questions:
How do I define teamMemberIDs since it's an array of values?
Is there a working example about this things?? The examples directory inside RestKit library only shows nested relationships.
Am I doing right? Am I missing something big?

Answer 1

I was struggling with this exact same problem, but was eventually able to find solution. Hopefully this will help you out.
Using the example:
You must have an NSArray property of Project, your NSManagedObject,
where you can map the teamMemberIDs to. To do this you make a transformable property.
Map teamMemberIDs to that property as you would a primitive.
Create a connectionDescription just as done in the example.