Swift 编码 class 不嵌套 super class

Question

总结： 我想对我的超级 class 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 得到以下输出：

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

如您所见，我们的 BasicEmployee super class 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，并且应与 GiftEmployee 结构的编码属性处于同一级别。

备注

我知道我可以通过更改结构的结构来避免所有麻烦，但是，现在这不可能。

如果我能在我的问题上得到任何帮助，我将不胜感激。

Answer 1

您可以调用 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)
}

Swift 编码 class 不嵌套 super class

Swift encode class without nesting super class

json

swift

codable

decodable

encodable

我的意思是：

备注