Decoding dynamic JSON structure in swift 4

Question

I have the following issue that I\'m not sure how to handle.

My JSON response can look like this:

{ 
  \"data\": {
      \"id\": 7,
      \"         


        

Answer 1

You can try

struct Root: Codable {
    let data: DataUnion
    let error: String?
}

enum DataUnion: Codable {
    case dataClass(DataClass)
    case datumArray([Datum])

    init(from decoder: Decoder) throws {
        let container = try decoder.singleValueContainer()
        if let x = try? container.decode([Datum].self) {
            self = .datumArray(x)
            return
        }
        if let x = try? container.decode(DataClass.self) {
            self = .dataClass(x)
            return
        }
        throw DecodingError.typeMismatch(DataUnion.self, DecodingError.Context(codingPath: decoder.codingPath, debugDescription: "Wrong type for DataUnion"))
    }

    func encode(to encoder: Encoder) throws {
        var container = encoder.singleValueContainer()
        switch self {
        case .dataClass(let x):
            try container.encode(x)
        case .datumArray(let x):
            try container.encode(x)
        }
    }
}

struct Datum: Codable {
    let id: Int
}

struct DataClass: Codable {
    let id: Int
    let token: String
}

---

let res = try? JSONDecoder().decode(Root.self, from:data)