RestKit与自我映射的多对多关系

Question

我在RestKit中映射ManyToMany自引用对象时遇到了麻烦。我正在尝试为对象类别实现父子关系类型。我确定它是简单的模式，但是我无法让它工作：CoreData创建的用于存储多对多关系（“Z_PARENT”）的中间表没有填充类别ID。

来自远程API的JSON：

{
"active": true,
"created": "2012-10-20 18:15:16",
"id": "60",
"name": "A Second Level",
"parent": [
    {
        "id": "59"
    }
], }

我的CoreData对象：

我的RestKit映射代码：

 RKManagedObjectMapping* categoryMapping = [RKManagedObjectMapping mappingForEntityWithName:@"Category" inManagedObjectStore:self.objectManager.objectStore];
categoryMapping.primaryKeyAttribute = @"backendID";
[categoryMapping mapKeyPath:@"id" toAttribute:@"backendID"];
[categoryMapping mapAttributes:@"active",@"created", @"name", nil];

[categoryMapping mapKeyPath:@"parent" toRelationship:@"parent" withMapping: [ RKDynamicObjectMapping dynamicMapping ]];