NSCoding Protocol - Swift Version

So, Swift is here and I'm working out examples of using Swift with the original frameworks. Here is a version of my NSCoding Protocol post using Swift. I split the Car class and main into two files: Car.swift and main.swift.

Car.swift:

//

//  Car.swift

//  SwiftArchiverDemo

//

//  Created by Tom Limbaugh on 6/7/14.

//

import Foundation

protocol NSCoding {

    

}

class Car:NSObject {

    

    var year: Int = 0

    var make: String = ""

    var model: String = ""

    

    init() {

        super.init()

    }

    

    func encodeWithCoder(aCoder: NSCoder!) {

        aCoder.encodeInteger(year, forKey:"year")

        aCoder.encodeObject(model, forKey:"make")

        aCoder.encodeObject(make, forKey:"model")

    }

    

    init(coder aDecoder: NSCoder!) {

        

        super.init()

        

        year = aDecoder.decodeIntegerForKey("year")

        make = aDecoder.decodeObjectForKey("make") as String

        model = aDecoder.decodeObjectForKey("model") as String

        

    }

}

main.swift creates three instances of the Car class for demonstrating the archiving and unarchiving of the objects.

//
//  main.swift
//  SwiftArchiverDemo
//
//  Created by Tom Limbaugh on 6/7/14.
//

import Foundation

var documentDirectories:NSArray
var documentDirectory:String
var path:String
var unarchivedCars:NSArray
var allCars:NSArray

// Create a filepath for archiving.

documentDirectories = NSSearchPathForDirectoriesInDomains(.DocumentDirectory, .UserDomainMask, true)

// Get document directory from that list

documentDirectory = documentDirectories.objectAtIndex(0) as String

// append with the .archive file name

path = documentDirectory.stringByAppendingPathComponent("swift_archiver_demo.archive")

var car1:Car! = Car()
var car2:Car! = Car()
var car3:Car! = Car()

car1.year = 1957

car1.make = "Chevrolet"

car1.model = "Bel Air"

car2.year = 1964

car2.make = "Dodge"

car2.model = "Polara"

car3.year = 1972

car3.make = "Plymouth"

car3.model = "Fury"

allCars = [car1, car2, car3]

// The 'archiveRootObject:toFile' returns a bool indicating
    // whether or not the operation was successful. We can use that to log a message.
if NSKeyedArchiver.archiveRootObject(allCars, toFile: path) {

    println("Success writing to file!")

} else {

    println("Unable to write to file!")

}

    

// Now lets unarchive the data and put it into a different array to verify
// that this all works. Unarchive the objects and put them in a new array
unarchivedCars = NSKeyedUnarchiver.unarchiveObjectWithFile(path) as NSArray

    

// Output the new array

for car : AnyObject in unarchivedCars {

    println("Here's a \(car.year) \(car.make) \(car.model)")

}

As with the original Objective-C post, if you’re running this as a command line tool, your *.archive file should be found in your '/Users/username/Documents directory'. If you open it with TextEdit.app, you should see a cryptic representation of the string data from the original objects.