The easiest way to store data model to file using `Codable` and `NSKeyedArchiver`.

CodableStorage.swift

import PlaygroundSupport
import Foundation

func load<T: Decodable>(from file: URL) -> T? {
    guard let data = NSKeyedUnarchiver.unarchiveObject(withFile: file.path) as? Data else { return nil }
    do {
        let products = try PropertyListDecoder().decode(T.self, from: data)
        print("Successful load")
        return products
    } catch let e {
        print("Load Failed: \(e)")
        return nil
    }
}

func store<T: Encodable>(data: T ,to file: URL) {
    do {
        let data = try PropertyListEncoder().encode(data)
        let success = NSKeyedArchiver.archiveRootObject(data, toFile: file.path)
        print(success ? "Successful save" : "Save Failed")
    } catch let e {
        print("Save Failed: \(e)")
    }
}

/*
 Usage:
 'Adding Codable to the inheritance list for Landmark triggers an automatic conformance that satisfies all of the protocol requirements from Encodable and Decodable'
 https://developer.apple.com/documentation/foundation/archives_and_serialization/encoding_and_decoding_custom_types
 */
struct Person: Codable {
    var name: String
    var age: Int
    var addedAt: Date
}

let path = playgroundSharedDataDirectory.appendingPathComponent("foo.plist")

//store or load object
var michael: Person? = Person(name: "Michael", age: 5, addedAt: Date())
store(data: michael, to: path)
michael = load(from: path)

//also you can store list or any object
let peter = Person(name: "Peter", age: 12, addedAt: Date())
store(data: [michael, peter], to: path)
let list:[Person?]? = load(from: path)