How can I store an array of custom objects (Goals)

Question

How can I store an array of objects of type Goal which I have created in NSUserDefaults? (in swift)

Here is the code:

func saveGoalList ( newGoalList : [Goal] ){
    let updatedGoalList = newGoalList;
    NSUserDefaults.standardUserDefaults().setObject(updatedGoalList, forKey: "GoalList")
    NSUserDefaults.standardUserDefaults().synchronize()
}

class GoalsViewController: MainPageContentViewController, UITableViewDelegate, UITableViewDataSource {
    @IBOutlet var tableView: GoalsTableView!

    var cell = GoalTableViewCell()

    var goalsArray : Array<Goal> = [] //

    override func viewDidLoad() {
        super.viewDidLoad()
        self.tableView.delegate = self
        self.tableView.dataSource = self

        if var storedGoalList: [Goal] = NSUserDefaults.standardUserDefaults().objectForKey("GoalList") as? [Goal]{
            goalsArray = storedGoalList;
        }
        var goal = Goal(title: "Walk the Dog")
        goalsArray.append(goal)
        saveGoalList(goalsArray)

        self.tableView?.reloadData()

        tableView.estimatedRowHeight = 44.0
        tableView.rowHeight = UITableViewAutomaticDimension

        self.xpnotificationView.alpha = 0.0
    }

    override func didReceiveMemoryWarning() {
        super.didReceiveMemoryWarning()
        // Dispose of any resources that can be recreated.
    }

    func tableView(tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
        return goalsArray.count //to ensure there is always an extra cell to fill in.
    }

    func tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCell { //recreate the cell and try using it.

        cell = tableView.dequeueReusableCellWithIdentifier("cell", forIndexPath: indexPath) as GoalTableViewCell

        cell.goalTextField.text = goalsArray[indexPath.row].title as String!
        cell.checkmarkImageView.visible = goalsArray[indexPath.row].checkmarked as Bool!

        if (cell.checkmarkImageView.visible == true) {
            cell.blackLineView.alpha = 1.0
        } else {
            cell.blackLineView.alpha = 0.0
        }

        return cell
    }

}

I understand that there are only certain data types that work with NSUserDefaults. Could anyone help me understand how I could do that?

Edit: Right now Goal inherits from NSObject.

Answer 1

I am posting code from a learning project I did to store objects using NSCoding. Fully functional and ready to use. A math game that was storing game variables, etc.

//********This class creates the object and properties to store********
import Foundation
class ButtonStates: NSObject {

    var sign: String = "+"
    var level: Int = 1
    var problems: Int = 10
    var time: Int = 30
    var skipWrongAnswers = true

    func encodeWithCoder(aCoder: NSCoder!) {
        aCoder.encodeObject(sign, forKey: "sign")
        aCoder.encodeInteger(level, forKey: "level")
        aCoder.encodeInteger(problems, forKey: "problems")
        aCoder.encodeInteger(time, forKey: "time")
        aCoder.encodeBool(skipWrongAnswers, forKey: "skipWrongAnswers")
    }

    init(coder aDecoder: NSCoder!) {
        sign = aDecoder.decodeObjectForKey("sign") as String
        level = aDecoder.decodeIntegerForKey("level")
        problems = aDecoder.decodeIntegerForKey("problems")
        time = aDecoder.decodeIntegerForKey("time")
        skipWrongAnswers = aDecoder.decodeBoolForKey("skipWrongAnswers")
    }

    override init() {
    }
}




   //********Here is the data archiving and retrieving class********
    class ArchiveButtonStates:NSObject {

        var documentDirectories:NSArray = []
        var documentDirectory:String = ""
        var path:String = ""

        func ArchiveButtons(#buttonStates: ButtonStates) {
            documentDirectories = NSSearchPathForDirectoriesInDomains(.DocumentDirectory, .UserDomainMask, true)
            documentDirectory = documentDirectories.objectAtIndex(0) as String
            path = documentDirectory.stringByAppendingPathComponent("buttonStates.archive")

            if NSKeyedArchiver.archiveRootObject(buttonStates, toFile: path) {
                //println("Success writing to file!")
            } else {
                println("Unable to write to file!")
            }
        }

        func RetrieveButtons() -> NSObject {
            var dataToRetrieve = ButtonStates()
            documentDirectories = NSSearchPathForDirectoriesInDomains(.DocumentDirectory, .UserDomainMask, true)
            documentDirectory = documentDirectories.objectAtIndex(0) as String
            path = documentDirectory.stringByAppendingPathComponent("buttonStates.archive")
            if let dataToRetrieve2 = NSKeyedUnarchiver.unarchiveObjectWithFile(path) as? ButtonStates {
                dataToRetrieve = dataToRetrieve2 as ButtonStates
            }
            return(dataToRetrieve)
        }
    }


the following is in my ViewController where the game is played.  Only showing the relevant code for retrieving and storing objects

class mathGame: UIViewController {

var buttonStates = ButtonStates()

override func viewWillAppear(animated: Bool) {
        super.viewWillAppear(animated)
        //set inital view

        //retrieving a stored object & placing property into local class variables
        buttonStates = ArchiveButtonStates().RetrieveButtons() as ButtonStates
        gameData.sign = buttonStates.sign
        gameData.level = buttonStates.level
        gameData.problems = buttonStates.problems
        gameData.time = buttonStates.time

    }

override func viewWillDisappear(animated: Bool) {
        super.viewWillDisappear(animated)

      //storing the object
      ArchiveButtonStates().ArchiveButtons(buttonStates: buttonStates)
    }
}