dynamic dictionary name decoder json

Question

Swift 4. I\'m in a very similar situation than Using Codable on a dynamic type/object but for me the changing variable is the name of the dictionary and not the keys inside. It

Answer 1

If you already know all the keys in the inner JSON, use a struct to take advantage of static typing. Assuming that there's only 1 key on the top level in your JSON (your customName key):

struct MyModel: Decodable {
    struct InnerModel: Decodable {
        var constantKey1: Double
        var constantKey2: Double
    }

    var customName: InnerModel

    init(from decoder: Decoder) throws {
        let container = try decoder.container(keyedBy: GenericCodingKeys.self)

        // Assume that there's only 1 key at the top level in the JSON
        if let key = container.allKeys.first {
            customName = try container.decode(InnerModel.self, forKey: key)
        } else {
            throw NSError(domain: NSCocoaErrorDomain, code: 0, userInfo: [NSLocalizedDescriptionKey: "JSON is empty"])
        }
    }
}