Loading a Swift based UIViewController from Objective-C

Question

I am attempting to load a view controller nib whose File's Owner is a Swift based UIViewController class. The view controller is very simple at this point--just a single label ( lblResult ) whose contents get set at runtime. When loading the view controller, I get the following error:

this class is not key value coding-compliant for the key lblResult

I know that this is usually because the File's Owner is not set in Interface Builder, however, in my case it IS set. I have verified that the IBOUtlet for lblResult is properly set and that the view property is also properly set. The only real difference here is that I am attempting to load the swift based view controller within an app written in Objective-C.

In my view controller class I am setting the UILabel property as follows:

@IBOutlet weak var lblResult: UILabel!

and setting its value as follows:

lblResult.text = "Time \(hour):\(minute):\(second)"

In my Obj-C calling class, I am instantiating the view controller as follows:

viewController = [[UIViewController alloc] initWithNibName:@"SwfViewController" bundle:nil];

The nib loads into view when no outlets are set, but when there are IBOutlets, i get the error. Any clues as to why this is happening? Thanks!

Answer 1

Is this view controller present in your storyboard? If yes, you need to load the view controller by calling.

viewController = self.storyboard?.instantiateViewControllerWithIdentifier("SwfViewController") as SwfViewController

Make sure you set the identifier of the view controller in the storyboard to SwfViewController.

The storyboard should look something like this.

Answer 2

If your nib is a View and the owner is a View Controller, make sure you connect your view controller's view property to the nib view. If your nib is a view controller, instead of setting the File Owner just set the Custom Class of the view controller to SwfViewController.