How to make a button modify another button functions - ios

Question

I have two UIViewController. In the first one, I have a button that adds some views, one at a time, to the main view. In the second one, I set up a store, so that when I press on a button I unlock some features of my app. Now, I perfectly know (I hope) how to handle the part where I make the VCs comunicate and I trigger some other easy functions, what I don't know is how to make the store button increase the button's functions.
WHAT I NEED:
Right now the button adds a maximum of 10 views (complete version). I want that before the user buys my app, he gets to add a maximum of 3 views and then, when he buys it, the function I already have (the one to add 10 views)starts to work and replaces the other one.
MAIN VIEW CONTROLLER
var messageArray = [UIView] ()
I attached all of my UIView from the storyboard and I appended them to my array in the viewDid load like this: messageArray.append(View1)
#IBAction func addMessageViewButton(_ sender: Any) {
let hiddenViews = messageArray.filter { $0.isHidden }
guard !hiddenViews.isEmpty else {
let sheet = UIAlertController(title: "max reached", message: nil, preferredStyle: .actionSheet)
let ok = UIAlertAction(title: "OK", style: .cancel, handler: nil)
let closeAll = UIAlertAction(title: "Close all", style: .destructive) { (addMessage) in
view1.isHidden = true
view2.isHidden = true
view3.isHidden = true
view4.isHidden = true
view5.isHidden = true
view6.isHidden = true
view7.isHidden = true
view8.isHidden = true
view9.isHidden = true
view10.isHidden = true
}
sheet.addAction(ok)
sheet.addAction(closeAll)
present(sheet, animated: true, completion: nil)
return
}
let randomHiddenView = hiddenViews.randomElement()
randomHiddenView?.isHidden = false
}
SHOP VIEW CONTROLLER
Here I won't post all of the code because it would be too much and of course unnecessary, since the important thing to know here is that there's a button and if the user presses it and he proceeds with the purchase, he will get the function I posted up here working instead of the one that allows him to have just 3 views.
func unlock() {
let appdelegate = UIApplication.shared.delegate
as! AppDelegate
appdelegate.viewController!.functionToHave10Views()
//viewControlled is declared in the app delegate like this ` var viewController: ViewController?`
//I know I don't physically have `functionToHave10Views()`, but I guess I'll turn the code of my button into a function, so just to be clear, I'm referring to that function.
buyButton.isEnabled = false
}

Answer 1

In your main view controller:
var isLocked = true
#IBAction func addMessageViewButton(_ sender: Any) {
if isLocked {
// Do something for when is locked
} else {
// Do something for when is unlocked
}
}
Then in your shop view controller:
func unlock() {
let appdelegate = UIApplication.shared.delegate as! AppDelegate
appdelegate.viewController!.isLocked = false
buyButton.isEnabled = false
}