Swift 4 approach for observeValue(forKeyPath:…)
Swift 4 introduced a family of concrete Key-Path types, a new Key-Path Expression to produce them and a new closure-based observe function available to classes that inherit NSObject. Using this new set of features, your particular example can now be expressed much more succinctly: self.observation = object.observe(\.keyPath) { [unowned self] object, change in self.someFunction() } … Read more