Dynamically change API data fetching structure

Question

I am fetching data from an API that keeps changing it's format several times a day from String to Double erratically..

Is it possible to do something to the struct to prevent returning nil when fetching and automatically using with the right type?

    struct BitcoinGBP : Decodable {
    let price : Double
    let percentChange24h : Double

    private enum CodingKeys : String, CodingKey {
        case price = "PRICE"
        case percentChange24h = "CHANGEPCT24HOUR"
    }
}

Would simply using Double? work?

Answer 1

Write a custom initializer to handle both cases

struct BitcoinGBP : Decodable {
    let price : Double
    let percentChange24h : Double

    private enum CodingKeys : String, CodingKey {
        case price = "PRICE"
        case percentChange24h = "CHANGEPCT24HOUR"
    }

    init(from decoder: Decoder) throws {
        let container = try decoder.container(keyedBy: CodingKeys.self)
        percentChange24h = try container.decode(Double.self, forKey: .percentChange24h)
        do {
            price = try container.decode(Double.self, forKey: .price)
        } catch DecodingError.typeMismatch(_, _) {
            let stringValue = try container.decode(String.self, forKey: .price)
            price = Double(stringValue)!
        }
    }
}