Deserialize JSON / NSDictionary to Swift objects

Question

Is there a way to properly deserialize a JSON response to Swift objects resp. using DTOs as containers for fixed JSON APIs?

Something similar to http://james.newtonk

Answer 1

Using quicktype, I generated your model and serialization helpers from your sample:

import Foundation

struct User: Codable {
    let name: String
    let email: String
    let password: String
}

extension User {
    static func from(json: String, using encoding: String.Encoding = .utf8) -> OtherUser? {
        guard let data = json.data(using: encoding) else { return nil }
        return OtherUser.from(data: data)
    }

    static func from(data: Data) -> OtherUser? {
        let decoder = JSONDecoder()
        return try? decoder.decode(OtherUser.self, from: data)
    }

    var jsonData: Data? {
        let encoder = JSONEncoder()
        return try? encoder.encode(self)
    }

    var jsonString: String? {
        guard let data = self.jsonData else { return nil }
        return String(data: data, encoding: .utf8)
    }
}

Then parse User values like this:

let user = User.from(json: """{
  "name": "myUser", 
  "email": "user@example.com",
  "password": "passwordHash"
}""")!