IBOutlet properties nil after custom view loaded from xib

Question

Something strange going on with IBOutlets. enter image description here

In code I've try to access to this properties, but they are nil. Code:

class CustomKeyboard: UIView {

    @IBOutlet var aButt: UIButton!
    @IBOutlet var oButt: UIButton!

    class func keyboard() -> UIView {
        let nib = UINib(nibName: "CustomKeyboard", bundle: nil)
        return nib.instantiateWithOwner(self, options: nil).first as UIView
    }

    override init() {
        super.init()
        commonInit()
    }

    override init(frame: CGRect) {
        super.init(frame: frame)
        commonInit()
    }

    required init(coder aDecoder: NSCoder) {
        super.init(coder: aDecoder)
        commonInit()
    }

    // MARK: - Private
    private func commonInit() {
        println(aButt)
        // aButt is nil

        aButt = self.viewWithTag(1) as UIButton
        println(aButt)
        // aButt is not nil
    }
}

@AshrafTawfeeq now nowhere. I can't normal init this class. Also clean project doesn't help — Gralex, Feb 07 '15 at 18:17
Outlets are not yet set at the time of init because the view has not been loaded. Your second log works because accessing the view causes it to be loaded. — rdelmar, Feb 07 '15 at 18:18
@rdelmar view already loaded, I can work with him. But it seems that outlet not connected. If I call `commonInit` directly from `ViewController` immediately after init, `aButt` not nill. — Gralex, Feb 07 '15 at 18:34
I spend hours trying to fix the similar problem. Before I understood that I attached the outlet to the wrong view :) — kelin, Mar 17 '18 at 22:05

score 72 · Accepted Answer · edited Jul 07 '22 at 09:03

72

That's expected, because the IBOutlet(s) are not assigned by the time the initializer is called.

Instead of calling commonInit() in init(coder:), do that in an override of awakeFromNib as follows:

// ...

required init(coder aDecoder: NSCoder) {
    super.init(coder: aDecoder)
}

override func awakeFromNib() {
    super.awakeFromNib()

    commonInit()
}

// ...

edited Jul 07 '22 at 09:03

Top-Master

7,611
5
39
71

answered Feb 07 '15 at 18:43

fz.

3,233
22
20

4

Already have that...Still getting the error. Also, my outlets are showing as connected, the class is matching in the xib. Even made the reference type strong, still nothing. – ScottyBlades Sep 19 '18 at 07:44
@ScottyBlades did you figure this out? – Marcelo Ribeiro Sep 20 '18 at 01:42
@MarceloRibeiro, no...I haven't. But I can tell you the are nil when called from `awakefromnib` but not `init(frame: CGRect)` – ScottyBlades Sep 20 '18 at 03:53
5

@MarceloRibeiro, you have to do this: ```override func awakeAfter(using aDecoder: NSCoder) -> Any? { guard subviews.isEmpty else { return self } return Bundle.main.loadNibNamed("MainNavbar", owner: nil, options: nil)?.first }``` – ScottyBlades Sep 20 '18 at 04:05
In my case I set `didSet` param for `IBInspectable` property and it fired earler than `awakeFromNib`. The solution is to use ? instead ! for outlets. – pirogtm Dec 30 '22 at 08:37

score 8 · Answer 2 · answered Sep 20 '18 at 04:07

Assuming you tried the standard troubleshooting steps for connecting IBOutlets, try this:

Apparently, you need to disable awake from nib in certain runtime cases.

  override func awakeAfter(using aDecoder: NSCoder) -> Any? {
      guard subviews.isEmpty else { return self }
      return Bundle.main.loadNibNamed("MainNavbar", owner: nil, options: nil)?.first
  }

score 1 · Answer 3 · answered Nov 30 '16 at 23:23

Your nib may not be connected. My solution is quite simple. Somewhere in your project (I create a class called UIViewExtension.swift), add an extension of UIView with this handy connectNibUI method.

extension UIView {
    func connectNibUI() {
        let nib = UINib(nibName: String(describing: type(of: self)), bundle: nil).instantiate(withOwner: self, options: nil)
        let nibView = nib.first as! UIView
        nibView.translatesAutoresizingMaskIntoConstraints = false

        self.addSubview(nibView)
        //I am using SnapKit cocoapod for this method, to update constraints.  You can use NSLayoutConstraints if you prefer.
        nibView.snp.makeConstraints { (make) -> Void in
            make.edges.equalTo(self)
        }
    }
}

Now you can call this method on any view, in your init method, do this:

override init(frame: CGRect) {
    super.init(frame: frame)
    connectNibUI()
}

Also make sure your view is connected via "Files Owner". – Josh O'Connor Nov 30 '16 at 23:23 — Josh O'Connor, Nov 30 '16 at 23:23

score 1 · Answer 4 · answered Mar 24 '19 at 18:56

Building on @ScottyBlades, I made this subclass:

class UIViewXib: UIView {
    // I'm finding this necessary when I name a Xib-based UIView in IB. Otherwise, the IBOutlets are not loaded in awakeFromNib.
    override func awakeAfter(using aDecoder: NSCoder) -> Any? {
        guard subviews.isEmpty else { return self }
        return Bundle.main.loadNibNamed(typeName(self), owner: nil, options: nil)?.first
    }
}

func typeName(_ some: Any) -> String {
    return (some is Any.Type) ? "\(some)" : "\(type(of: some))"
}

Though there is one problem with this approach. All the settings done through xib is lost since the view reinitializes itself. But at least outlets of subviews are intact. — atulkhatri, Apr 05 '20 at 07:54

score -1 · Answer 5 · answered Nov 02 '20 at 06:45

-1

There is possibility that you not mentioned the FileOwner for xib. Mention its class in File owner not in views Identity Inspector .

answered Nov 02 '20 at 06:45

Abhishek B

157
8

score -3 · Answer 6 · answered Feb 07 '15 at 17:20

-3

And how did you initiate your view from the controlller? Like this:

var view = CustomKeyboard.keyboard()
self.view.addSubview(view)

answered Feb 07 '15 at 17:20

szpetip

333
6
12

Like this: `textField.inputView = CustomKeyboard.keyboard()` It's doest matter. – Gralex Feb 07 '15 at 18:18
You didn't post your code and if you use `var view = CustomKeyboard();` then the result will like in your case: your outlets are getting nil. This is why I asked. – szpetip Feb 07 '15 at 18:26

IBOutlet properties nil after custom view loaded from xib

6 Answers6