Set an Alter name for property in Decodable class | Swift

Question

I'm developing an existing Android Kotlin app for IOS Swift UI.

In Kotlin when using Gson, I had a Client model class:

abstract class Client(
        @SerializedName("nombre")
        var name: String? = null,
        @SerializedName(value="cliente_id", alternate = ["id"])
        var client_id: Int = -1,
)

As you can see, I use @SerializedName() to give Client property name or client_id an alter name. I do this because when I get the data from the API, Client Json has "nombre" and not "name" as I want. So @SerializedName() makes possible to detect "nombre" in JSON as "name" or detect "cliente_id" as "client_id" in Kotlin model Classes. This way I can read data from API using my own property names.

Well, now I'm facing the same issue in Swift. I want to use my own property names and not the API JSON property names.

My swift Client model class looks like this:

class Client: Identifiable, Decodable{
    
    init(id: Int, token: String) {
        self.cliente_id = id
        self.token = token
    }
    
    let cliente_id: Int
    let token: String
}

And I get client data from API like this:

let request = AF.request(
    url, method: .post,
    parameters: parameters,
    encoder: JSONParameterEncoder.default
)

request.validate(statusCode: 200...299)
request.responseDecodable(of: Client.self) { response in
    if let loginResponse = response.value{//Success
        loginPublisher.send(loginResponse)
    }
    else{//Failure
        loginPublisher.send(completion: Subscribers.Completion.failure(.thingsJustHappen))
    }
}

In order to be able to use Client a decodable, Client has to implement Decodable. Well, all I want is Client to has id and not cliente_id as a property name.

Something like

class Client: Identifiable, Decodable{

    init(id: Int, token: String) {
        self.id = id
        self.token = token
    }

    @NameforDecode("cliente_id")
    let id: Int
    let token: String
}

Is this possible?

user_7948372 · Answer

In Swift you achieve this by giving your type custom CodingKeys:

extension Client: Decodable {

    enum CodingKeys: String, CodingKey {
        case id = "cliente_id"
        case token
    }
}

Enum cases have to correspond to your properties; the raw value can be declared as a String if the keys in the JSON don't match your property names. There's more information in the Encoding and Decoding Custom Types developer article.

Set an Alter name for property in Decodable class | Swift

1 Answers