Using Selector in Swift 3

Question

I am writing my iOS Application in Swift 3.

I have a

UIViewController

extension, where I have to check if the controller instance responds to a method. Below is the code that I a trying out.

extension UIViewController {

func myMethod() {

    if self.responds(to: #selector(someMethod)) {



    }

}}

Here the

responds(to:)

method throws a compile time error

Use of unresolved identifier "someMethod".

I read in another post, we have to use

self

inside the selector argument, but even that is throwing some error.

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Answer 1

A simple workaround:

@objc protocol SomeMethodType {
    func someMethod()
}
extension UIViewController {
    func myMethod() {
        if self.responds(to: #selector(SomeMethodType.someMethod)) {
            //...
            self.perform(#selector(SomeMethodType.someMethod))
            // or
            (self as AnyObject).someMethod?()
            //...
        }
    }
}

A little more Swifty way:

protocol SomeMethodType {
    func someMethod()
}
//For all classes implementing `someMethod()`.
extension MyViewController: SomeMethodType {}
//...
extension UIViewController {
    func myMethod() {
        if let someMethodSelf = self as? SomeMethodType {
            //...
            someMethodSelf.someMethod()
            //...
        }
    }
}

Using Selector in Swift 3

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