Register React Native Navigation External Component in Swift

AppDelegate.m

//#import "AppDelegate.h"

//#import <React/RCTBridge.h>
//#import <React/RCTBundleURLProvider.h>

//#import "RNNCustomViewController.h"
//#import <ReactNativeNavigation/ReactNativeNavigation.h>


class AppDelegate : RCTBridgeDelegate {

    func application(application:UIApplication!, didFinishLaunchingWithOptions launchOptions:NSDictionary!) -> Bool {

        self.window = UIWindow(frame:UIScreen.mainScreen().bounds)
        if #available(iOS 13.0, *) {
            self.window.backgroundColor = UIColor.systemBackgroundColor()
        } else {
            self.window.backgroundColor = UIColor.whiteColor()
        }
        self.window.makeKeyWindow()

        let bridge:RCTBridge! = RCTBridge(delegate:self, launchOptions:launchOptions)
        ReactNativeNavigation.bootstrapWithBridge(bridge)
        ReactNativeNavigation.registerExternalComponent("RNNCustomComponent",
                             callback:{ (props:NSDictionary!,bridge:RCTBridge!) in 
                               return RNNCustomViewController(props:props)
                             })

        return true
    }

    // MARK: - RCTBridgeDelegate

    func sourceURLForBridge(bridge:RCTBridge!) -> NSURL! {
#if DEBUG
        return RCTBundleURLProvider.sharedSettings().jsBundleURLForBundleRoot("index",
                                                              fallbackResource:nil)
#else
        return NSBundle.mainBundle().URLForResource("main", withExtension:"jsbundle")
#endif
    }

    func extraModulesForBridge(bridge:RCTBridge!) -> [AnyObject]! {
        return ReactNativeNavigation.extraModulesForBridge(bridge)
    }
}