Swift Codable init

Question

I would like to do some initialization logic after the Swift Coding/Encoding feature has finished decoding a JSON.

struct MyStruct: Codable {
    let id: Int 
           


        

Answer 1

Either you get everything for free but standardized or you have to write a custom initializer like

struct MyStruct: Codable  {

    let id: Int 
    var name: String

    init(from decoder: Decoder) throws {
        let container = try decoder.container(keyedBy: CodingKeys.self)
        id = try container.decode(Int.self, forKey: .id)
        let decodedName = try container.decode(String.self, forKey: .name)
        name = "\(id) \(decodedName)" 
    }
}

You can implement init() but this works independent of the decoding functionality and you have to assign a default value to all non-optional properties, that's what the error says.