json - 当属性可以是整数或布尔值时，什么解析对象？

Question

有时服务器会向我发送布尔属性（真，假）。有时服务器将属性作为整数 (0,1) 发送给我。

如何通过 Swift 4 中的标准 Decodable 解码这种情况？

例子。我有：

final class MyOffer : Codable {
    var id = 0
    var pickupAsap: Int?

    enum CodingKeys: String, CodingKey {
         case id
         case pickupAsap = "pickup_asap"
    }
}

来自服务器的响应是：

1）“pickup_all_day”：真，

2）“pickup_all_day”：0

Answer 1

您可以实现自己的 decode init 方法，从 decode 容器中获取每个类属性，在本节中，让您的逻辑处理“asap”是 Int 还是 Bool，最后签署所有必需的类属性。

这是我制作的一个简单演示：

class Demo: Decodable {
    var id = 0
    var pickupAsap: Int?

    enum CodingKeys: String, CodingKey {
        case id
        case pickupAsap = "pickup_asap"
    }

    required init(from decoder: Decoder) throws {
        let container = try decoder.container(keyedBy: CodingKeys.self)
        let id = try container.decode(Int.self, forKey: .id)
        let pickupAsapBool = try? container.decode(Bool.self, forKey: .pickupAsap)
        let pickupAsapInt = try? container.decode(Int.self, forKey: .pickupAsap)
        self.pickupAsap = pickupAsapInt ?? (pickupAsapBool! ? 1 : 0)
        self.id = id
    }
}

模拟数据：

 let jsonInt = """
{"id": 10,
 "pickup_asap": 0
}
""".data(using: .utf8)!

let jsonBool = """
{"id": 10,
 "pickup_asap": true
}
""".data(using: .utf8)!

测试：

let jsonDecoder = JSONDecoder()
let result = try! jsonDecoder.decode(Demo.self, from: jsonInt)
print("asap with Int: \(result.pickupAsap)")

let result2 = try! jsonDecoder.decode(Demo.self, from: jsonBool)
print("asap with Bool: \(result2.pickupAsap)")

输出：

asap with Int: Optional(0)
asap with Bool: Optional(1)

更多信息：Apple 的编码和解码文档