IBOutlet is nil, but it is connected in storyboard

Question

Using Swift 1.1 and Xcode 6.2.

I have a UIStoryboard containing a singular, custom UIViewController subclass. On it, I have an @IBOutlet connection of type UIView from that controller to a UIView subclass on the storyboard. I also have similar outlets for subviews of that view. See figure A.

But at run time, these properties are nil (Figure B). Even though I have assured I've connected the outlets in Interface Builder.

Thoughts:

• Is it possible that because I am using a subclass of a subclass something messes up with the initialization? I am not overriding any initializers
• awakeFromNib: is not getting called for some reason
• Maybe it doesn't connecting to subviews on subviews

Things I have tried:

• Matching @IBOutlet and storyboard item types exactly (instead of UIView)
• Deleting property and outlet and re-added them

Figure A*

Figure B

*The obscured code in Figure A is:

@IBOutlet private var annotationOptionsView: UIView!
@IBOutlet private var arrivingLeavingSwitch: UISegmentedControl!

Thank you.

Answer 1

1. select both .h and .m view controller files
2. remove the reference of those files
3. re-add the files to your project tree
4. open the storyboard, eventually re-build the project

Answer 2

Typically this happens because your view controller hasn't loaded its view hierarchy yet. A view controller only loads its view hierarchy when something sends it the view message. The system does this when it is time to actually put the view hierarchy on the screen, which happens after things like prepareForSegue:sender: and viewWillAppear: have returned.

Since your VC hasn't loaded its view hierarchy yet, your outlets are still nil.

You could force the VC to load its view hierarchy by saying _ = self.view.

Answer 3

For me, I had same error on a localized storyboard, an element was added in some locale and not in the other, so I had null reference for that element when switched to the missing element locale, I had to remove (redundant) localization for that storyboard using https://stackoverflow.com/a/42256341/1356559.

Answer 4

If you have two main.storyboards and you are making changes to the wrong one this can happen. This can happen anytime you connect an outlet from an uninstantiated storyboard.

Answer 5

This happened for me because I was accidentally instantiating my view controller directly instead of instantiating it through the storyboard. If you instantiate directly via MyViewController() then the outlets won't be connected.

Answer 6

You can call controller.view to force to load the view to initialize the IBOutlets, then you will be able to assign the values.

override func prepareForSegue(segue: UIStoryboardSegue, sender: AnyObject!) {
    if (segue.identifier == "identifier") {
        let controller = segue.destinationViewController as! YourController
        let _ = controller.view //force to load the view to initialize the IBOutlets

        controller.your_IBOutlet_property = xxx
        ...
        controller.delegate = self
    }
}