SingleValueDecoding+DecodeIfPresent.swift

SingleValueDecoding+DecodeIfPresent.swift

extension SingleValueDecodingContainer {
    func decodeIfPresent<T>(_ type: T.Type) -> T? where T : Decodable {
        print(type)
        return try? decode(type)
    }
}


struct MonitorStatus: Decodable {

    var string: String?
    var int: Int?
    var bool: Bool?

    init(_ s: String){
        self.string = s
    }
    init(_ b: Bool){
        bool = b
    }
    init(_ i: Int){
        int = i
    }

    init(from decoder: Decoder) throws {
        let container = try decoder.singleValueContainer()
        self = try container.decodeIfPresent(String.self).map(MonitorStatus.init)
            ?? container.decodeIfPresent(Int.self).map(MonitorStatus.init)
            ?? MonitorStatus(container.decode(Bool.self))
    }
}

let stringData = try JSONEncoder().encode("test")
let intData = try JSONEncoder().encode(123)
let boolData = try JSONEncoder().encode(false)

let stringStatus = try JSONDecoder().decode(MonitorStatus.self, from: stringData)
let intStatus = try JSONDecoder().decode(MonitorStatus.self, from: intData)
let boolStatus = try JSONDecoder().decode(MonitorStatus.self, from: boolData)