UITableViewAlertForLayoutOutsideViewHierarchy error: Warning once only (iOS 13 GM)

Question

I am getting a strange error with iOS13 when performing a Segue and I can\'t figure out what it means, nor can I find any documentation for this error. The problem is that t

Answer 1

Like @joe-h, I was getting this error and was also surprised as the unwind approach he shows above is one used by lots of developers + is in some significant Apple iOS sample code.

The triggering line in my code (@joe-h, I'm guessing likely in yours, too) is a tableView.reloadRows at the selectedIndexPath (which is an unwrapped tableView.indexPathForSelectedRow):

tableView.reloadRows(at: [selectedIndexPath], with: .automatic)

Unfortunately commenting out the row isn't an option if you are unwinding after updating the value in an existing tableView row (which is an approach in the Apple FoodTracker tutorial mentioned above, as well as one used in Apple's Everyone Can Code series). If you don't reload the row(s) then your change won't show in the tableView. After commenting out the reload in the unwind, I added a viewDidAppear with the following code and this seems to fix things:

override func viewDidAppear(_ animated: Bool) {
    super.viewDidAppear(animated)
    if let selectedIndexPath = tableView.indexPathForSelectedRow {
        tableView.reloadRows(at: [selectedIndexPath], with: .automatic)
    }
}

I'd welcome comments on whether this is a sound approach, but for now, this seems to be working.