SWIFT - Observe contentSize fro the tableView

ViewController.Swift

class ViewController: UIViewController {
    @IBOutlet weak var tableView: UITableView!
    @IBOutlet weak var heightTableView: NSLayoutConstraint!
    
    override func viewWillAppear(_ animated: Bool) {
        super.viewWillAppear(animated)
        tableView.addObserver(self, 
                              forKeyPath: "contentSize", 
                              options: .new, 
                              context: nil)
    }

    override func viewWillDisappear(_ animated: Bool) {
        super.viewWillDisappear(animated)
        tableView.removeObserver(self, 
                                 forKeyPath: "contentSize")
    }

    override func observeValue(forKeyPath keyPath: String?, of object: Any?, 
                               change: [NSKeyValueChangeKey : Any]?, 
                               context: UnsafeMutableRawPointer?) {
        
        if let obj = object as? UITableView, 
                obj == self.tableView && 
                keyPath == "contentSize" {
                 heightTableView.constant = tableView.contentSize.height
            }
        }
    }
}

terbaique (y)

This code has potential problem in case where this VC pushes/presents another screen. TableView observer is removed immediately and will not be added back when the VC reappears

I would add it on viewDidLoad and remove it on deinit instead.