How to parse JSON with Decodable protocol when property types might change from Int to String?

Question

I have to decode a JSON with a big structure and a lot of nested arrays. I have reproduced the structure in my UserModel file, and it works, except with one property (postco

Answer 1

You can use generic like this:

enum Either {
    case left(L)
    case right(R)
}

extension Either: Decodable where L: Decodable, R: Decodable {
    init(from decoder: Decoder) throws {
        let container = try decoder.singleValueContainer()
        if let left = try? container.decode(L.self) {
            self = .left(left)
        } else if let right = try? container.decode(R.self) {
            self = .right(right)
        } else {
            throw DecodingError.typeMismatch(Either.self, .init(codingPath: decoder.codingPath, debugDescription: "Expected either `\(L.self)` or `\(R.self)`"))
        }
    }
}

extension Either: Encodable where L: Encodable, R: Encodable {
    func encode(to encoder: Encoder) throws {
        var container = encoder.singleValueContainer()
        switch self {
        case let .left(left):
            try container.encode(left)
        case let .right(right):
            try container.encode(right)
        }
    }
}

And then declare postcode: Either and if your model is Decodable and all other fields are Decodable too no extra code would be needed.