willSelectRowAt and didSelectRowAt not called anymore since Xcode 9 / Swift 4

Question

Since I've upgraded to Xcode 9 / Swift 4 some of my UITableViewDelegate methods are not called anymore

Answer 1

As of Xcode 9 / Swift 4 all Objective-C methods should be marked @objc. The compiler does a reasonable job of recognizing where it should be applied however it doesn't figure out inheritance. For example:

class Delegate: NSObject, UITableViewDelegate {
}

class SuperDelegate: Delegate {
    override func tableView(_ tableView: UITableView, willSelectRowAt indexPath: IndexPath) -> IndexPath? { return indexPath }
}

This will not generate any warning, crashing or build error. However your line will not be called until you add @objc:

@objc class SuperDelegate: Delegate {
    override func tableView(_ tableView: UITableView, willSelectRowAt indexPath: IndexPath) -> IndexPath? { return indexPath }
}