ios - 使用可编码的对象

Question

我有一个应用程序，我尝试使用 UserDefaults 在本地保存一个 Codable 模型，但问题是 UserDefault 没有存储所有的Model 的 values 并将 nil 分配给其中一些，有时会分配适当的 value。所以我决定尝试一个替代方案，即 realm 并且我能够修改我的 model 以使用 realm 但我有一个问题不是哪个正在过程中解码对象在对象使用 Realm 。在使用 List 但非 array Objects 处理 Array object 时，我能够使其工作只是未能映射到JSON

下面是我正在处理的示例数组

{
    "id": 732,
    "name": "Vendor Name",
    "logo": ".../thumb/missing.png",
    "kitchens":
      {
        "id": 36,
        "name": "Sandwiches"
      }
  }

模型类

class VendorsList : Object, Decodable {
    @objc dynamic var id : Int = 0
    @objc dynamic var name : String?
    @objc dynamic var logo : String?
    // Create your Realm List.
    var kitchensList = List<VendorKitchens>()

    override class func primaryKey() -> String? {
        return "id"
    }

    private enum CodingKeys: String, CodingKey {
        case id
        case name
        case logo
        // Set JSON Object Key
        case kitchensList = "kitchens"

    }

    public required convenience init(from decoder: Decoder) throws {
        self.init()
        let container = try decoder.container(keyedBy: CodingKeys.self)
        self.id = try container.decode(Int.self, forKey: .id)
        self.name = try container.decode(String.self, forKey: .name)
        self.logo = try container.decode(String.self, forKey: .logo)
        // Map your JSON Array response
        let kitchens = try container.decodeIfPresent([VendorKitchens].self, forKey: .kitchensList) ?? [VendorKitchens()]
        kitchensList.append(objectsIn: kitchens)

    }

}


class VendorKitchens : Object, Decodable {
    @objc dynamic var id : Int = 0
    @objc dynamic var name : String?

    override class func primaryKey() -> String? {
        return "id"
    }

    private enum CodingKeys: String, CodingKey {
        case id
        case name
    }
}

这返回一个错误

Failed to map data to JSON

Answer 1

来，试试这个。

class VendorsList : Object, Decodable {
    @objc dynamic var id : Int = 0
    @objc dynamic var name : String?
    @objc dynamic var logo : String?
    @objc dynamic var kitchens: VendorKitchens? = nil

    override class func primaryKey() -> String? {
        return "id"
    }

    private enum CodingKeys: String, CodingKey {
        case id
        case name
        case logo
        case kitchens = "kitchens"

    }

    public required convenience init(from decoder: Decoder) throws {
        self.init()
        let container = try decoder.container(keyedBy: CodingKeys.self)
        self.id = try container.decode(Int.self, forKey: .id)
        self.name = try container.decode(String.self, forKey: .name)
        self.logo = try container.decode(String.self, forKey: .logo)
        kitchens = try container.decodeIfPresent(VendorKitchens.self, forKey: .kitchensList)

    }

}


class VendorKitchens : Object, Decodable {
    @objc dynamic var id : Int = 0
    @objc dynamic var name : String?

    override class func primaryKey() -> String? {
        return "id"
    }

    private enum CodingKeys: String, CodingKey {
        case id
        case name
    }
}