Swift 编码类而不嵌套超类

Question

摘要：我想对超类的所有字段进行编码，而不将它们嵌套在 json 结果中。

我的意思是：

假设我们有这些结构：

struct Toy: Codable {
var name: String
}
class BasicEmployee: Codable {
var name: String
var id: Int
init(name: String, id: Int) {
self.name = name
self.id = id
}
}
class GiftEmployee: BasicEmployee {
var birthday: Date
var toy: Toy
enum CodingKeys: CodingKey {
case employee, birthday, toy
}
init(name: String, id: Int, birthday: Date, toy: Toy) {
self.birthday = birthday
self.toy = toy
super.init(name: name, id: id)
}
required init(from decoder: Decoder) throws {
let container = try decoder.container(keyedBy: CodingKeys.self)
birthday = try container.decode(Date.self, forKey: .birthday)
toy = try container.decode(Toy.self, forKey: .toy)
let baseDecoder = try container.superDecoder(forKey: .employee)
try super.init(from: baseDecoder)
}
override func encode(to encoder: Encoder) throws {
var container = encoder.container(keyedBy: CodingKeys.self)
try container.encode(birthday, forKey: .birthday)
try container.encode(toy, forKey: .toy)
let baseEncoder = container.superEncoder(forKey: .employee)
try super.encode(to: baseEncoder)
}
}

现在我们决定像这样对GiftEmployee对象进行编码：

let encoder = JSONEncoder()
let decoder = JSONDecoder()
let giftEmployee = GiftEmployee(name: "John Appleseed", id: 7, birthday: Date(), toy: Toy(name: "Teddy Bear"))
let giftData = try encoder.encode(giftEmployee)
let giftString = String(data: giftData, encoding: .utf8)!

打印出giftString会给我们以下输出：

{"toy":{"name":"Teddy Bear"},"employee":{"name":"John Appleseed","id":7},"birthday":597607945.92342305}

如您所见，我们的 BasicEmployee 超级类的所有属性都嵌套在"employee"json 字段中。

但是，我不想这样。我希望giftString的输出如下：

{"toy":{"name":"Teddy Bear"},"name":"John Appleseed","id":7,"birthday":597607945.92342305}

BasicEmployee结构的属性不应嵌套，而不应与GiftEmployee结构的编码属性位于同一级别。

注意

我知道我可以通过更改结构结构来避免所有麻烦，但是，现在这是不可能的。

我将非常感谢我能在我的问题上得到的任何帮助。

Answer 1

你可以调用super.init(from:)和super.encode(to:)：

required init(from decoder: Decoder) throws {
let container = try decoder.container(keyedBy: CodingKeys.self)
birthday = try container.decode(Date.self, forKey: .birthday)
toy = try container.decode(Toy.self, forKey: .toy)
super.init(from: decoder)
}
override func encode(to encoder: Encoder) throws {
var container = encoder.container(keyedBy: CodingKeys.self)
try container.encode(birthday, forKey: .birthday)
try container.encode(toy, forKey: .toy)
try super.encode(to: encoder)
}