UIAlertController : UICollectionViewFlowLayout is not defined warning every time I try to bringup a UIAlertcontroller

Question

I am using a UIAlertController for taking user input and updating a table cell. Everytime when I try to create a alert, I get this following warning in console

2015-11-19 17:51:42.034 SimpleTableView[5488:584215] the behavior of the UICollectionViewFlowLayout is not defined because:

2015-11-19 17:51:42.035 SimpleTableView[5488:584215] the item height must be less than the height of the UICollectionView minus the section insets top and bottom values, minus the content insets top and bottom values.

2015-11-19 17:51:42.036 SimpleTableView[5488:584215] The relevant UICollectionViewFlowLayout instance is <_UIAlertControllerCollectionViewFlowLayout: 0x7fd0a057c3d0>, and it is attached to ; layer = ; contentOffset: {0, 0}; contentSize: {0, 0}> collection view layout: <_UIAlertControllerCollectionViewFlowLayout: 0x7fd0a057c3d0>. 2015-11-19 17:51:42.036 SimpleTableView[5488:584215] Make a symbolic breakpoint at UICollectionViewFlowLayoutBreakForInvalidSizes to catch this in the debugger.

The implementation is pretty straightforward as mentioned in numerous blogs,

func displayAlertInfo(){
    let alertController = UIAlertController(title: "New Race", message: "Type in a new race", preferredStyle: .Alert)
    let cancelAction = UIAlertAction(title: "Cancel", style: .Cancel) { (_) in
        alertController.dismissViewControllerAnimated(true, completion: nil)
    }
    let addAction = UIAlertAction(title: "Add", style: .Default) { (_) in
        let textFieldInput = alertController.textFields![0] as UITextField
        let newRace = textFieldInput.text?.capitalizedString
        DataManager.sharedInstance.addRace(species: self.species, race: newRace!)
        let newIndexPath = NSIndexPath(forRow: self.races.count - 1, inSection: 0)
        self.racesTableVew.insertRowsAtIndexPaths([newIndexPath], withRowAnimation: UITableViewRowAnimation.Automatic)
    }

    alertController.addTextFieldWithConfigurationHandler { (textField) -> Void in
        textField.placeholder = "New Race"
    }

    alertController.addAction(cancelAction)
    alertController.addAction(addAction)

    self.presentViewController(alertController, animated: true, completion: nil)
}

I call this function on a navigation button tap. The alert displays correctly, but I keep on getting this warning everytime I try to tap the button which creates the alert. What am I doing wrong or am I skipping something ?

EDIT : Added Screenshot : The alert is called from navigation item button, over a tableView.

Answer 1

You need to call

alertcontroller.view.setNeedsLayout()

right before

self.presentViewController(alertController, animated: true, completion: nil)

Source: https://forums.developer.apple.com/thread/18294 (last answer)

Answer 2

I had a similar problem: worked fine on iPhone 6 Plus portrait, failed in landscape. I made one small change: from

 message: nil,  

to:

 message: "this is a nice long line of crapthis is a nice long line of crapthis is a nice long line of crap",

..which was long enough to wrap, adding two newlines. And my problem was solved. But a shorter message that didn't line-wrap at least twice still caused the error to occur.

I then found that

 message: "\n\n"  

worked just as well, but a message of a single newline failed. And if I set title: nil, I needed more newlines in message. It appears to be related to the total height of the alert, title and message combined.

Note: other alerts without a text field didn't show the same problem. And in my case, setNeedsLayout() didn't make any difference.

(Of course, adding that many lines makes the alert too tall to appear on smaller iPhones in landscape once you include the pop-up keyboard, generating the same flood of error messages. So I wound up making the addition of those lines conditional on the height and width of the screen being larger than a set value.)

Answer 3

I also had same issue in my screen for only iphon6 plus screen. Please check, if you are not passing empty title, if title is empty , pass it nil like :

 UIAlertController *confirmAlert = [UIAlertController alertControllerWithTitle:nil message:displayMessage preferredStyle:UIAlertControllerStyleAlert];

instead of

  UIAlertController *confirmAlert = [UIAlertController alertControllerWithTitle:@"" message:displayMessage preferredStyle:UIAlertControllerStyleAlert];

it fixed my problem. Good luck..