View inside property observer throwing "Unexpectedly found nil while implicitly unwrapping an Optional value: file"

Question

I am trying to update the view based on the change in items variable but cartView is nil in didSet

@IBOutlet weak var cartView: UIView!

var items = 0 {
    didSet{
        if items > 0 {
            cartView.isHidden = false
        } else {
            cartView.isHidden = true
        }
    }
    willSet{}
}

Updating this var from tableviewcell like this -- ''' class ItemListingItemsTableViewCell: UITableViewCell {

@IBOutlet weak var itemTypeImage: UIImageView!


@IBOutlet weak var itemName: UILabel!

@IBOutlet weak var itemPrice: UILabel!

@IBOutlet weak var itemAdd: UIButton!

@IBOutlet weak var itemMinus: UIButton!

@IBOutlet weak var itemPlus: UIButton!

@IBOutlet weak var buttonsview: UIView!


**var itemVC = ItemListingViewController()**



@IBAction func addItemInitial(_ sender: Any) {
    itemAdd.isEnabled = false
    itemAdd.setTitle("1", for: .normal)
    itemAdd.setTitleColor(UIColor.white, for: .normal)
    itemMinus.isHidden = false
    itemPlus.isHidden = false

    itemVC.items = itemVC.items + 1


}'''

You are probably setting the `items` from another controller. You should make sure `cartView` is initialized (and loaded) before calling it. — Mojtaba Hosseini, Nov 07 '19 at 14:57
Possible duplicate of [What does "fatal error: unexpectedly found nil while unwrapping an Optional value" mean?](https://stackoverflow.com/questions/32170456/what-does-fatal-error-unexpectedly-found-nil-while-unwrapping-an-optional-valu) — user28434'mstep, Nov 07 '19 at 15:00
Yes, I am setting items from the tableviewcell class and viewDidLoad is being called before this property observer — keerthi, Nov 07 '19 at 15:02
Basically you need to check whether your `cartView` is not `nil` in the begging of `didSet`, e.g. `guard cartView != nil else { return }` — Dennis Pashkov, Nov 07 '19 at 15:38
@user28434 Thank you, that seems efficient but my problem is with the cartView always returning nil. Can you suggest any way to update this view? — keerthi, Nov 07 '19 at 15:47

score 1 · Answer 1 · answered Nov 07 '19 at 15:52

1

That's because you are modifying count before the outlet cartView is set. I've modified your code by checking if cartView is nil + added an observer to the cartView itself, so once the outlet is assigned, your cartView immediately updates its state based on the count property value.

Please also make sure that cartView outlet is connected in your xib/storyboard.

@IBOutlet private weak var cartView: UIView! {
    didSet {
        updateCartViewVisibility()
    }
}

var items = 0 {
    didSet{
        updateCartViewVisibility()
    }
}

private func updateCartViewVisibility() {
    guard cartView != nil else { return }
    cartView.isHidden = items == .zero
}

answered Nov 07 '19 at 15:52

Dennis Pashkov

934
10
24

Thanks for the solution, but even here all the views are nil. I can't understand what I am doing wrong – keerthi Nov 07 '19 at 16:08
@keerthi then your Outlet is not set. Check storyboard/xib – Dennis Pashkov Nov 07 '19 at 16:13
It is connected to the storyboard – keerthi Nov 07 '19 at 16:42
I understood my mistake, In my tableViewCell I am referencing the view controller like var itemVC = ItemListingViewController() which is the reason why the views are not initialised. Can you suggest some other way to update variable in view controller from tableviewcell? – keerthi Nov 08 '19 at 06:54
@keerthi difficult to say anything without the code – Dennis Pashkov Nov 08 '19 at 10:10
Oh that's okay, thanks for the help! It is fixed now. I shifted the entire logic to view controller. – keerthi Nov 08 '19 at 12:07

View inside property observer throwing "Unexpectedly found nil while implicitly unwrapping an Optional value: file"

1 Answers1