Trouble Referencing UIButton using NSMutableAttributedString in Instantiated View Controller - swift

Question

As soon as my view controller loads, I am presented with a button (gray background with white font) that displays the text “Sto 1”. This is called in viewWillLayoutSubviews and the title is set using a NSMutableAttributedString. “Sto” is short for store.
For my application, I would like the user to be able to select the Sto 1 button and be able to store a number that is presented on a UILabel. I am able to grab the current number being displayed but I’m unable to update the text inside my Sto 1 button using NSMutableAttributedString. In other words I want to go from the button showing “Sto 1” to displaying some number (e.g., 12).
Thank you all for any help you may be able to provide me. I am still relatively new to Swift and I have been trying to resolve this issue over the past week.
import UIKit
class ViewController: UIViewController {
var fontConstant = CGFloat()
var someRandomNumberDisplayedOnAUILabel = String(12)
#IBOutlet weak var myButton: UIButton!
override func viewDidLoad() {
super.viewDidLoad()
}
override func viewWillLayoutSubviews() {
fontConstant = 1
let myString = "Sto 1"
let myAttributes = [NSAttributedString.Key.foregroundColor : UIColor(red: 251/255.0, green: 251/255.0, blue: 251/255.0, alpha: 1.0), NSAttributedString.Key.font : UIFont.systemFont(ofSize: 10 * fontConstant)]
let mutableAttributedString = NSMutableAttributedString(string: myString, attributes: myAttributes)
myButton.setAttributedTitle(mutableAttributedString, for: .normal)
myButton.backgroundColor = UIColor(red: 94/255.0, green: 94/255.0, blue: 94/255.0, alpha: 1.0)
}
#IBAction func myButtonAction(_ sender: Any) {
let myAttributes = [NSAttributedString.Key.foregroundColor : UIColor(red: 0/255.0, green: 0/255.0, blue: 0/255.0, alpha: 1.0), NSAttributedString.Key.font : UIFont.systemFont(ofSize: 10 * fontConstant)]
let mutableAttributedString = NSMutableAttributedString(string: someRandomNumberDisplayedOnAUILabel, attributes: myAttributes)
myButton.setAttributedTitle(mutableAttributedString, for: .normal)
myButton.backgroundColor = UIColor(red: 251/255.0, green: 251/255.0, blue: 251/255.0, alpha: 1.0)
}}

Answer 1

Normally, you would use setTitle(:for:) to change the text on a UIButton. But since you're working with an NSMutableAttributedString you will need the setAttributedTitle(:for:) function. I think this might be what you're looking for:
myButton.setAttributedTitle(myNSMutableAttributedString, for: .normal)
Heads up, though. You might need to call this function for the different control states and not just .normal otherwise you might see different text for an instant as the button is highlighted. Here is a list of the control states.
EDIT:I would try referencing the sender in the IBAction instead of myButton. This might be a quick fix:
#IBAction func myButtonAction(_ sender: Any) {
let myAttributes = [NSAttributedString.Key.foregroundColor : UIColor(red: 0/255.0, green: 0/255.0, blue: 0/255.0, alpha: 1.0), NSAttributedString.Key.font : UIFont.systemFont(ofSize: 10 * fontConstant)]
let mutableAttributedString = NSMutableAttributedString(string: someRandomNumberDisplayedOnAUILabel, attributes: myAttributes)
guard let button = sender as? UIButton else {
print("Error: sender was not a button")
return
}
button.setAttributedTitle(mutableAttributedString, for: .normal)
button.backgroundColor = UIColor(red: 251/255.0, green: 251/255.0, blue: 251/255.0, alpha: 1.0)
}
EDIT #2:If you're losing the reference to your IBOutlet you might be able to work around that by assigning a selector to the button before you lose it. Try this:
override func viewDidLoad() {
super.viewDidLoad()
// Add the action to the button rather than holding on to the IBOutlet
myButton.addTarget(self, action: #selector(RideInProgressViewController.myAction(sender:)), for: .touchUpInside)
}
#objc private func myAction(sender: Any) {
guard let button = sender as? UIButton else {
print("Error: sender was not a button")
return
}
let myAttributes = [NSAttributedString.Key.foregroundColor : UIColor(red: 0/255.0, green: 0/255.0, blue: 0/255.0, alpha: 1.0), NSAttributedString.Key.font : UIFont.systemFont(ofSize: 10 * fontConstant)]
let mutableAttributedString = NSMutableAttributedString(string: someRandomNumberDisplayedOnAUILabel, attributes: myAttributes)
button.setAttributedTitle(mutableAttributedString, for: .normal)
button.backgroundColor = UIColor(red: 251/255.0, green: 251/255.0, blue: 251/255.0, alpha: 1.0)
}