使用可解码的领域快捷列表

Question

我想弄清楚如何使用Swift 4中的新特性来解析领域列表，解码协议。

这里是一个例子JSON：

[{ 
    "name": "Jack", 
    "lastName": "Sparrow", 
    "number": "1", 
    "address": [ 
     { 
      "city": "New York", 
      "street": "av. test" 
     } 
    ] 
    }, 
    { 
    "name": "Cody", 
    "lastName": "Black", 
    "number": "2" 
    }, 
    { 
    "name": "Name", 
    "lastName": "LastName", 
    "number": "4", 
    "address": [ 
     { 
      "city": "Berlin", 
      "street": "av. test2" 
     }, 
     { 
      "city": "Minsk", 
      "street": "av. test3" 
     } 
    ] 
    }] 

和领域型号：

人

public final class Person: Object, Decodable { 

    @objc dynamic var name = "" 
    @objc dynamic var lastName = "" 
    var address = List<Place>() 

    override public static func primaryKey() -> String? { 
     return "lastName" 
    } 

    private enum CodingKeys: String, CodingKey { case name, lastName, address} 

    convenience public init(from decoder: Decoder) throws { 
     self.init() 
     let container = try decoder.container(keyedBy: CodingKeys.self) 
     self.name = try container.decode(String.self, forKey: .name) 
     self.lastName = try container.decode(String.self, forKey: .lastName) 
     self.address = try container.decodeIfPresent(List<Place>.self, forKey: .address) ?? List() 
    } 
} 

地点

public final class Place: Object, Decodable { 

    @objc dynamic var city = "" 
    @objc dynamic var street = 0 

    override public static func primaryKey() -> String? { 
     return "street" 
    } 
// We dont need to implement coding keys becouse there is nothing optional and the model is not expanded by extra properties. 
} 

和解析此JSON会的结果：

[Person { 
    name = Jack; 
    lastName = Sparrow; 
    number = 1; 
    address = List<Place> <0x6080002496c0> (

    ); 
}, Person { 
    name = Cody; 
    lastName = Black; 
    number = 2; 
    address = List<Place> <0x6080002496c0> (

    ); 
}, Person { 
    name = Name; 
    lastName = LastName; 
    number = 4; 
    address = List<Place> <0x6080002496c0> (

    ); 

我们可以看到我们的名单总是空的。

self.address = try container.decodeIfPresent(List<Place>.self, forKey: .address) ?? List() 

将永远是nil。

而且我扩展由List：

extension List: Decodable { 
    public convenience init(from decoder: Decoder) throws { 
     self.init() 
    } 
} 

任何想法可能是错误的？

EDIT

struct LoginJSON: Decodable { 
    let token: String 
    let firstCustomArrayOfObjects: [FirstCustomArrayOfObjects] 
    let secondCustomArrayOfObjects: [SecondCustomArrayOfObjects] 
    let preferences: Preferences 
    let person: [Person] 
} 

每个属性（而不是令牌）是一种类型的Realm Object和最后一个是从上面的一个。

谢谢！

Answer 1

您不能直接从您的JSON转到列表。 JSON中的内容是阵列。因此，这条线将不起作用：

self.address = try container.decodeIfPresent(List<Place>.self, forKey: .address) ?? List() 

你必须通过取得阵列启动：

if let arr = try container.decodeIfPresent(Array<Place>.self, forKey: .address) { 
    // arr is now an array of Place 
    self.address = // make a List from `arr`, however one does that 
} else { 
    self.address = nil 
}