Stackview label not adding programmatically - swift

Question

I'm trying to do everything without a story board but keep getting nil when adding my label but I can't see why. Im sure its dead simple and I'm being blind but I just can't see it after a lot of googling.
View Controller:
class SquaresViewController: UIViewController {
let stackView = OAStackView()
let titleView = TitleView(frame: CGRect.zero)
#IBOutlet var squaresCollectionView: UICollectionView!
override func viewDidLoad() {
super.viewDidLoad()
stackView.axis = .vertical
stackView.translatesAutoresizingMaskIntoConstraints = false
stackView.addArrangedSubview(titleView)
titleView.snp.makeConstraints { make in
make.height.equalTo(50)
make.top.equalTo(view.snp.top)
make.left.equalTo(view.snp.left)
make.right.equalTo(view.snp.right)
}
}
}
titleView:
import UIKit
class TitleView: UIView {
#IBOutlet weak var titleText: UILabel!
override init(frame: CGRect) {
super.init(frame: frame)
self.translatesAutoresizingMaskIntoConstraints = false
createView()
}
required init?(coder aDecoder: NSCoder) {
fatalError("init(coder:) has not been implemented")
}
func createView() {
titleText = UILabel(frame: CGRect.zero)
titleText.translatesAutoresizingMaskIntoConstraints = false
titleText.text = "Tappy tap tap a square!"
titleText.textAlignment = .center
titleText.numberOfLines = 0
self.addSubview(titleText)
titleText.snp.makeConstraints { make in
make.edges.equalTo( self.snp.edges )
}
}
}
When building it fails at:
titleText.translatesAutoresizingMaskIntoConstraints = false
with:
fatal error: unexpectedly found nil while unwrapping an Optional value

Answer 1

First of all, I don't understand why you created an IBOutlet for titleText if you don't want to use storyboards. If you don't want to use storyboards, change the implementation to:
var titleText : UILabel!
Secondly, the application is crashing because you are asking it to perform an operation on a view that is not yet added to the hierarchy. For ease of reading I have commented out all lines except those that are important. See below:
func createView() {
//titleText = UILabel(frame: CGRect.zero)
titleText.translatesAutoresizingMaskIntoConstraints = false // <-- You are trying to perform an operation on titleText here
//titleText.text = "Tappy tap tap a square!"
//titleText.textAlignment = .center
//titleText.numberOfLines = 0
self.addSubview(titleText) // <-- but you are adding it to the view hierarchy here
//titleText.snp.makeConstraints { make in
//make.edges.equalTo( self.snp.edges )
//}
}
titleText has to be added to the view hierarchy before you can call translatesAutoresizingMaskIntoConstraints on it, like so:
self.view.addSubview(titleText)
titleText.translatesAutoresizingMaskIntoConstraints = false // <-- Here we are waiting until the view has been added to the hierarchy to perform operations on it
So try changing implementation to look like so:
import UIKit
class TitleView: UIView {
var titleText: UILabel!
override init(frame: CGRect) {
// leave as is, removed for space
}
required init?(coder aDecoder: NSCoder) {
// leave as is, removed for space
}
func createView() {
titleText = UILabel(frame: CGRect.zero)
titleText.text = "Tappy tap tap a square!"
titleText.textAlignment = .center
titleText.numberOfLines = 0
self.addSubview(titleText)
titleText.translatesAutoresizingMaskIntoConstraints = false
titleText.snp.makeConstraints { make in
make.edges.equalTo( self.snp.edges )
}
}
}