Implementing Force Update Feature using Firebase Remote Config in iOS

AppDelegate+Extensions.swift

//Mark:- RemoteConfig Setup
extension MyAppDelegate {
    func setupRemoteConfig(){
        
        remoteConfig = RemoteConfig.remoteConfig()
        remoteConfig.configSettings = RemoteConfigSettings(developerModeEnabled: true)!
        
        //set in app defaults
        let defaults : [String : Any] = [
            ForceUpdateChecker.FORCE_UPDATE_REQUIRED : false,
            ForceUpdateChecker.FORCE_UPDATE_CURRENT_VERSION : "1.0(1)",
            ForceUpdateChecker.FORCE_UPDATE_STORE_URL : "https://itunes.apple.com/us/app/myapp/id12345678?ls=1&mt=8"
        ]
        
        remoteConfig.setDefaults(defaults as? [String : NSObject])
        
        var expirationDuration = 60
        // If your app is using developer mode, expirationDuration is set to 0, so each fetch will
        // retrieve values from the service.
        if remoteConfig.configSettings.isDeveloperModeEnabled {
            expirationDuration = 0
        }
        
        remoteConfig.fetch(withExpirationDuration: TimeInterval(expirationDuration)) { [weak self] (status, error) in
            if status == .success {
                print("config fetch done")
                self?.remoteConfig.activateFetched()
            } else {
                print("Config not fetched")
                print("Error: \(error?.localizedDescription ?? "No error available.")")
            }
        }
    }
}

extension MyAppDelegate : OnUpdateNeededListener {
    func onUpdateNeeded(updateUrl: String) {
        
        let controller = UIStoryboard(name: "Main", bundle: nil).instantiateViewController(withIdentifier: "UpdateAppViewController") as! UpdateAppViewController
        controller.url = updateUrl
        
        if(self.appVisibleController is SplashViewController){
            self.appVisibleController?.present(controller, animated: false, completion: nil)
        } else if ( !( self.appVisibleController is UpdateAppViewController ) ){
            self.appVisibleController?.present(controller, animated: false, completion: nil)
        }
        
    }
    
    func onNoUpdateNeeded() {
        print("onNoUpdateNeeded()")
        if(self.appVisibleController is UpdateAppViewController){
            self.appVisibleController?.dismiss(animated: false, completion: nil)
        }
    }
}