NSCoder.md

NSCoder

A way of encoding custom objects to be stored on disk. Same tech used for JSON encoding. To be Encodable means you only contain standard object types (strings, floats, ints etc).

Example

import UIKit

struct Item: Codable {
    let name: String
}

class ViewController: UIViewController {

        let items = [Item(name: "Kevin"), Item(name: "Sam")]
        
        // Create your own plist file entry. Stored in the documents dir.
        // .../Documents/Items.plist
        guard let dataFilePath = FileManager.default.urls(for: .documentDirectory, in: .userDomainMask).first?.appendingPathComponent("Items.plist") else { return }
        print(dataFilePath)
        
        // Encode
        let encoder = PropertyListEncoder()
        let data = try? encoder.encode(items)
        try? data?.write(to: dataFilePath)
        
        // Decode
        guard let data2 = try? Data(contentsOf: dataFilePath) else { return }
        let decoder = PropertyListDecoder()
        let newItems = try? decoder.decode([Item].self, from: data2)
        print(newItems)
}

Links that help

• Apple Docs