Error -> init(coder:) has not been implemented

Question

Created Jan ’22

Replies 7

Boosts 0

Views 2.6k

Participants 3

I'm trying to access another class in my CollectionView Controller but when I try and initialise the class I get the error

Here is the class

@MainActor
class AlbumsViewModel {

    private let albumService: AlbumService
    private let favouritesService: FavouritesService
    private let recommendationService: RecommendationService

    @Published var favourites = [Bool]()
    @Published var recommendedAlbums = [Album]()
    @Published var allAlbums = [Album]() {

        didSet {
            updateFavourites()
        }

    }

    init(albumService: AlbumService, favouritesService: FavouritesService, recommendationService: RecommendationService) {

        self.albumService = albumService
        self.favouritesService = favouritesService
        self.recommendationService = recommendationService

    }
...(functions here)

Collectionview Controller Class

class CVC: UICollectionViewController, UICollectionViewDelegateFlowLayout {

    var viewModel: AlbumsViewModel

    init?(viewModel: AlbumsViewModel, coder: NSCoder) {
        self.viewModel = viewModel

        super.init(coder: coder)
    }

    required init?(coder: NSCoder) {

        fatalError("init(coder:) has not been implemented")
    }

    override func viewDidLoad() {
        super.viewDidLoad()

        collectionView.delaysContentTouches = false

        Task {
            print(viewModel.allAlbums)
        }


    } // End viewDidLoad
...

Trying to recreate this https://martinmitrevski.com/2021/07/11/ml-recommendation-app-with-create-ml-on-ios-15/

Boost

Answer 1

robnotyou OP

Jan ’22

Where is the error... which class, which line?

0

Answer 2

Junaid6305 OP

Jan ’22

The error is in the the collection view class at required init?(coder: NSCoder) { fatalError("init(coder:) has not been implemented") }

0

Answer 3

robnotyou OP

Jan ’22

How are you initializing the CVC?

0

Answer 4

Junaid6305 OP

Jan ’22

The init method above that

0

Answer 5

robnotyou OP

Jan ’22

You have defined CVC init(coder:) to throw a fatal error.

You don't show where you are initializing the CVC... ...but it seems that init(coder:) is being called, since you are seeing the error.

You need to implement a proper init(coder:)...

required init?(coder: NSCoder) {
    super.init(coder: coder)
    /// any other setup action here... what about viewModel?
}

... or use your custom initializer instead.

1

Answer 6

Claude31 OP

Jan ’22

You should add at least super.init and remove fatal error.

What I often do is define a sharedInit() func that I call in all init, including coder.

        self.sharedInit()

0

Answer 7

robnotyou OP

Jan ’22

Accepted Answer

You are instantiating the CVC directly from your Storyboard.
So you can't pass in the viewModel property.

You will have to think of another way to use viewModel in CVC. For example, as a global singleton, like this...

In AlbumsViewModel:

static let shared = AlbumsViewModel(albumService:favouritesService:recommendationService:) // however you initialise it

...then in CVC, refer to

AlbumsViewModel.shared

...or create a shortcut property

let viewModel = AlbumsViewModel.shared

0