Run method on class knowing only its name

Question

how can I launch method knowing its name (as String)

// key.rawValue.firstUppercased is `ApiAddress`
let result = preferencesRepository.perform(Selector("get\(key.rawValue.firstUppercased)"))

where preferencesRepository has method getApiAddress() and conforms to NSObject

public class RealPreferencesRepository: NSObject {
    func getApiAddress() -> String
// ...

I have fatal error:

*** Terminating app due to uncaught exception 'NSInvalidArgumentException',
reason: '-[PreferencesModule.RealPreferencesRepository getApiAddress]:
unrecognized selector sent to instance 0x600000090a70'

thanks for help in advance

Answer 1

You need to prefix the getApiAddress() method with @objc attribute.

Also, since the return value of the perform method is Unmanaged, you need to use takeRetainedValue() to convert the return value.

public class RealPreferencesRepository: NSObject {
    @objc func getApiAddress() -> String {
        return "success"
    }
}

let preferencesRepository = RealPreferencesRepository()

let result = preferencesRepository.perform(Selector("getApiAddress"))
let value = result?.takeRetainedValue() as! String
print(value)
// => success