import { nanoid } from 'nanoid/non-secure'; import * as React from 'react'; import { SingleNavigatorContext } from './EnsureSingleNavigator'; /** * Register a navigator in the parent context (either a navigation container or a screen). * This is used to prevent multiple navigators under a single container or screen. */ export function useRegisterNavigator() { const [key] = React.useState(() => nanoid()); const container = React.useContext(SingleNavigatorContext); if (container === undefined) { throw new Error( "Couldn't register the navigator. Have you wrapped your app with 'NavigationContainer'?\n\nThis can also happen if there are multiple copies of '@react-navigation' packages installed." ); } React.useEffect(() => { const { register, unregister } = container; register(key); return () => unregister(key); }, [container, key]); return key; }