Swift Decode and Encode Custom Types - swift

Question

I'm having difficulties decoding and encoding one of my classes in Swift. I have tried following the Encoding and Decoding Custom Types documentation but with no luck.
My class layout is as follows:
public struct MapLocation: Identifiable, Codable {
#DocumentID public var id: String?
let originLocation: [MapLandmark]
let destinationLocation: [MapLandmark]
enum CodingKeys: String, CodingKey {
case originLocation
case destinationLocation
}
}
import Foundation
import MapKit
struct MapLandmark: Codable {
let placemark: MKPlacemark
var id: UUID {
return UUID()
}
var name: String {
self.placemark.name ?? ""
}
var title: String {
self.placemark.title ?? ""
}
var coordinate: CLLocationCoordinate2D {
self.placemark.coordinate
}
}
I have tried adding the encoding and decoding classes from the above link but keep running into errors. What is the best way to implement a solution?
EDIT:
I forgot to mention the errors I am getting are:
"Type 'MapLandmark' does not conform to protocol 'Decodable'"
"Type 'MapLandmark' does not conform to protocol 'Encodable"

Answer 1

MKPlacemark conforms to NSSecureCoding. You can just use NSKeyedArchiver and NSKeyedUnarchiver to encode/decode it. UUID already conforms to Codable. Try as follow:
import MapKit
extension NSSecureCoding {
func archived() throws -> Data {
try NSKeyedArchiver.archivedData(withRootObject: self, requiringSecureCoding: false)
}
}
extension Data {
func unarchived<T: NSSecureCoding>() throws -> T? {
try NSKeyedUnarchiver.unarchiveTopLevelObjectWithData(self) as? T
}
}
struct MapLandmark: Codable {
let placemark: MKPlacemark
let id: UUID
func encode(to encoder: Encoder) throws {
var unkeyedContainer = encoder.unkeyedContainer()
try unkeyedContainer.encode(placemark.archived())
try unkeyedContainer.encode(id)
}
public init(from decoder: Decoder) throws {
var container = try decoder.unkeyedContainer()
placemark = try container.decode(Data.self).unarchived()!
id = try container.decode(UUID.self)
}
}