Iboutlet Is Nil

IBOutlet is nil, but it is connected in storyboard, Swift

The storyboard wasn't recognizing any further UI things I added to it. At run time all the references were nil. So I cleared my derived data folder and then those connections worked again.

IBOutlet is nil

To see where the outlet is being set to nil, try this:

@IBOutlet weak var labelView: UIView? {
    didSet {
        print("labelView: \(labelView)")
    }
}

You should see it set to an initial value when the view is loaded. If it then gets set to nil, put a breakpoint on the print and your should be able to see from the backtrace where it's happening.

Swift/iOS: IBOutlet nil after loading view controller

The problem is the reference to InfoViewController(), which instantiates the view controller independent of any storyboard scene. You want to use instantiateViewController:

let infoViewController = storyboard?.instantiateViewController(withIdentifier: "Info") as! InfoViewController
infoViewController.modalPresentationStyle = .overCurrentContext
present(infoViewController, animated: true) {
    infoViewController.displayInfo()
}

A couple of notes:

• This assumes that (a) you've given the scene in the storyboard a "storyboard id"; (b) you've set the base class for that scene to InfoViewController.

• Note, I called displayInfo in the completion handler of present because you probably don't want that called until the scene has been presented and the outlets have been hooked up.

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Alternatively, you can update non-outlet properties of the InfoViewController immediately after instantiating it and then have its viewDidLoad take those properties and update the outlets, e.g.:

class InfoViewController: UIViewController {
    var info: String!
    @IBOutlet weak var infoLabel: UILabel!

    override func viewDidLoad() {
        super.viewDidLoad()
        infoLabel.attributedText = NSAttributedString(string: info)
    }
}

Note, I changed the @IBOutlet name to be infoLabel and added the String property called info. That tends to be the convention, that outlets bear some suffix indicating the type of control, and model objects, like the String property, are without the suffix. (You'll just want to make sure you remove that old outlet in the connections inspector in IB so that you don't have problems with these property name changes.)

Anyway, you can then do:

let infoViewController = storyboard?.instantiateViewController(withIdentifier: "Info") as! InfoViewController
infoViewController.info = "abc"
infoViewController.modalPresentationStyle = .overCurrentContext
present(infoViewController, animated: true, completion: nil)

The key point is don't try to update outlets of the scene immediately after instantiating it, but make sure that this is deferred until after viewDidLoad was called.

IBOutlet elements come out nil when I try to set them in viewDidLoad

I've had the same problem under iOS7 on very slow devices.

Just wait for your views to be rendered in viewDidLayoutSubviews then do your changes.
Don't forget to do so just once though for viewDidLayoutSubviews is being called a lot.

var first = false

override func viewDidLayoutSubviews() { 
    super.viewDidLayoutSubviews()
    if self.first {
        //Update your views
        self.first = false
    }
}

You could also use view.layoutSubviews() but I recommend you not to ;)

EDIT

I did not see the problem at first sight but you are creating your view controllers from scratch! You must instantiate them using a storyboard or your IBOutlets won't be set ;)

var vc1 = storyboard?.instantiateViewControllerWithIdentifier("YourControllerStoryboardId") as! CarouselViewController

Hope this'll help!

IBOutlet nil - button

It’s not a “bug”. Your code is what’s at fault. It has nothing to do with pushing vs presenting. It’s that this line is wrong:

let v = RegisterController()

That creates a barebones view controller with no outlets hooked up. The outlets are hooked up in the storyboard instance of this class. Create the view controller from the storyboard as you did in the first code, and all will be well.

let v = UIStoryboard(name: "Main", bundle: nil).instantiateViewController(withIdentifier: "signup") as! RegisterController

Xib's IBOutlets returning nil when using Xib in storyboard

This is happening Because the xib was never loaded

So what you can do here is, First add a simple UIView in the viewController rather than TimeRangeView

@IBOutlet var timeRangeContainerView: UIView!

Now in viewDidLoad add Fetch the xib by using

let timeRangeView = Bundle.main.loadNibNamed("TimeRangeView", owner: self, options: nil)?[0] as? TimeRangeView

And add this as a subview of timeRangeContainerView

override func viewDidLoad() {
    super.viewDidLoad()
    let timeRangeView = Bundle.main.loadNibNamed("TimeRangeView", owner: self, options: nil)?[0] as? TimeRangeView

    timeRangeView.frame = CGRect(origin: CGPoint.zero, size: self.timeRangeContainerView.frame.size)

    self.timeRangeContainerView.insertSubview(timeRangeView, at: 0)

    //  Add constraints
    timeRangeView.leadingAnchor.constraint(equalTo: self.leadingAnchor, constant: 10).isActive = true
    timeRangeView.trailingAnchor.constraint(equalTo: self.trailingAnchor, constant: 0).isActive = true
    timeRangeView.topAnchor.constraint(equalTo: self.topAnchor, constant: 0).isActive = true
    timeRangeView.bottomAnchor.constraint(equalTo: self.bottomAnchor, constant: 0).isActive = true
    timeRangeView.translatesAutoresizingMaskIntoConstraints = false  

    //Add the rest of your code here
}

The constraints are optional

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