Restkit：外键关系的存根答案

【问题标题】：Restkit: Stubs for foreign key relationshipsRestkit：外键关系的存根
【发布时间】：2015-09-25 07:28:28
【问题描述】：

在给定以下两个 REST API 端点的情况下，我很难理解如何映射用户和团队对象。我一直在阅读我在 SO 上能找到的所有内容，最接近的 QA 是这个RestKit: Creating stubs for foreign key relationships，但我无法适应我的情况。

/用户

 {
      "success": 1,
      "users": [{
           "success": 1,
           "name": "Damjan",
           "surname": "Mozetič",
           "teams": [1, 2]
      }]
 }

/团队

 {
      "success": 1,
      "teams": [{
          "id": 1,
          "title": "Team name",
          "user": 1  
      }]
 }

User.swift

class User: NSManagedObject {
    @NSManaged var userId: NSNumber
    @NSManaged var firstName: String
    @NSManaged var lastName: String

    @NSManaged var teams: NSSet?

    @NSManaged var teamFKIds: NSNumber? // FK
}

团队快速

class Team: NSManagedObject {
    @NSManaged var teamId: NSNumber
    @NSManaged var title: String

    @NSManaged var user: User?
}

映射：

// User
let userMapping = RKEntityMapping(forEntityForName: "User", inManagedObjectStore: mos)
userMapping.identificationAttributes = ["userId"]
userMapping.addAttributeMappingsFromDictionary([
    "id": "userId",
    "name": "firstName",
    "surname": "lastName",
    "team": "teamName",
    "teams": "teamFKIds"
])
objectManager.addResponseDescriptor(RKResponseDescriptor(mapping: userMapping, method: .GET, pathPattern: "users", keyPath: nil, statusCodes: RKStatusCodeIndexSetForClass(.Successful)))

// Team
let teamMapping = RKEntityMapping(forEntityForName: "Team", inManagedObjectStore: mos)
teamMapping.identificationAttributes = ["teamId"]
teamMapping.addAttributeMappingsFromDictionary([
    "id": "teamId",
    "title": "title"
])
objectManager.addResponseDescriptor(RKResponseDescriptor(mapping: teamMapping, method: .GET, pathPattern: "teams", keyPath: nil, statusCodes: RKStatusCodeIndexSetForClass(.Successful)))

userMapping.addConnectionForRelationship("teams", connectedBy: ["teamFKIds": "teamId"])

根据我一直在阅读的内容，为 FK 创建存根是可行的方法，就像这样，虽然我知道我已经搞砸了一点：

let profileStubMapping = RKEntityMapping(forEntityForName: "Profile", inManagedObjectStore: mos)
userStubMapping.addPropertyMapping(RKAttributeMapping(fromKeyPath: nil, toKeyPath: "teamFKIds"))
userStubMapping.identificationAttributes = ["userId"]
objectManager.addResponseDescriptor(RKResponseDescriptor(mapping: userStubMapping, method: .Any, pathPattern: "teams", keyPath: "userId", statusCodes: RKStatusCodeIndexSetForClass(.Successful)))

有人可以帮我了解如何正确设置吗？

另外，还有一个问题。最终我的计划是将整个图表检索到核心数据中。我如何实现这一目标？只需为“/users”和“/teams”调用 getObjectsAtPath 就可以完成这项工作吗？

最后，我计划让事情离线工作并在上线时同步。有什么实现的技巧吗？

谢谢。

【问题讨论】：

您是否总是首先获得用户，然后才是团队？看来您只需要通过零键路径映射来存根，就是这样......
@Wain 是的，我确实首先获得用户。你能告诉我如何通过 nil keypath 设置存根吗？这是我难以理解的部分。

标签： swift mapping restkit foreign-key-relationship restkit-0.24.x

【解决方案1】：

看起来你想要一些类似的东西：

let userMapping = RKEntityMapping(forEntityForName: "User", inManagedObjectStore: mos)
userMapping.identificationAttributes = ["userId"]
userMapping.addAttributeMappingsFromDictionary([
    "id": "userId",
    "name": "firstName",
    "surname": "lastName"
])

let teamStubMapping = RKEntityMapping(forEntityForName: "Team", inManagedObjectStore: mos)
teamStubMapping.addPropertyMapping(RKAttributeMapping(fromKeyPath: nil, toKeyPath: "teamId"))
teamStubMapping.identificationAttributes = ["teamId"]

userMapping.addRelationshipMapping(sourceKeyPath: "teams", mapping: teamStubMapping)

【讨论】：