Get 'NSInvalidArgumentException' 'Attempt to insert non-property list object when saving class type array to UserDefaults

Question

In below TableViewController, I'm trying to store a class type array(playList) to UserDefaults then retrieve it in each table cell. But as opening this table View, app is crashed with `"Terminating app due to uncaught exception 'NSInvalidArgumentException', reason: 'Attempt to insert non-property list object ( "LocalMusicPlayer.SongData" ) for key playList'", but if the data is simply string array, it works.

Just come to UserDefaults today, want to ask if it is not supported for storing class type data or some extra method like defaults.object(forKey: "playList") should be involved?

Another question is that in real implementation, if I should put initialization of UserDefaults operations to some other files' init() but not under viewDidLoad() of a View. Your help is appreciated!

/// Well, below is my SongData and TableView file.

/// 9.4, 2019, involve NSObject and NSCoding, it is working now.

import UIKit

class SongData: NSObject, NSCoding {

    var songName: String
    var artistName: String
    var albumName: String
    var albumArtwork: UIImage
    var url: URL

    init(songName: String, artistName: String, albumName: String, albumArtwork: UIImage, url: URL) {
        self.songName = songName
        self.artistName = artistName
        self.albumName = albumName
        self.albumArtwork = albumArtwork
        self.url = url
    }

    // MARK: -NSCoding
    func encode(with aCoder: NSCoder) {
        aCoder.encode(songName, forKey: "songName")
        aCoder.encode(artistName, forKey: "artistName")
        aCoder.encode(albumName, forKey: "albumName")
        aCoder.encode(albumArtwork, forKey: "albumArtwork")
        aCoder.encode(url, forKey: "url")
    }

    required init?(coder aDecoder: NSCoder) {
        songName = aDecoder.decodeObject(forKey: "songName") as! String
        artistName = aDecoder.decodeObject(forKey: "artistName") as! String
        albumName = aDecoder.decodeObject(forKey: "albumName") as! String
        albumArtwork = aDecoder.decodeObject(forKey: "albumArtwork") as! UIImage
        url = aDecoder.decodeObject(forKey: "url") as! URL
    }
}

/// Table View

import UIKit

class PlaylistTableViewController: UITableViewController {

    var song: SongData?
    var playList = [SongData]()
    let defaults = UserDefaults.standard

    override func viewDidLoad() {
        super.viewDidLoad()

        playList.append(SongData(songName: "You Belong With Me", artistName: "Tylor Swift", albumName: "Love", albumArtwork: UIImage(named: "Apple")!, url: URL(fileURLWithPath: "file:///private/var/mobile/Containers/Data/Application/14E1BC3D-65A6-4854-9CD6-A8740265F341/Documents/Just%20Dance.mp3")))
        playList.append(SongData(songName: "Just Dance", artistName: "Lady Gaga", albumName: "Love", albumArtwork: UIImage(named: "Apple")!, url: URL(fileURLWithPath: "file:///private/var/mobile/Containers/Data/Application/14E1BC3D-65A6-4854-9CD6-A8740265F341/Documents/Just%20Dance.mp3")))

        let encodedData = try! NSKeyedArchiver.archivedData(withRootObject: playList, requiringSecureCoding: false)
        defaults.set(encodedData, forKey: "playList")
    }

    // MARK: - Table view data source

    override func numberOfSections(in tableView: UITableView) -> Int {
        // #warning Incomplete implementation, return the number of sections
        return 1
    }

    override func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
        // #warning Incomplete implementation, return the number of rows
        return playList.count
    }

    override func tableView(_ tableView: UITableView, titleForHeaderInSection section: Int) -> String? {
            return "PLAYLISTS"
    }


    override func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
        let cell = tableView.dequeueReusableCell(withIdentifier: "playListLabelCell", for: indexPath)

        let decoded = defaults.object(forKey: "playList") as! Data
        let decodedTeams = try! NSKeyedUnarchiver.unarchiveTopLevelObjectWithData(decoded) as! [SongData]
        cell.textLabel?.text = decodedTeams[indexPath.row].songName
        cell.detailTextLabel?.text = decodedTeams[indexPath.row].artistName
        cell.imageView?.image = decodedTeams[indexPath.row].albumArtwork

        return cell
    }
}