gistfile1.txt

// RNative Webview Parent
class App extends Component {
constructor(props) {
    super(props);
    this.webviewRef = null;
}

async componentDidMount() {
    if (Platform.OS === 'android') {
            const permission = await PermissionsAndroid.request(
                PermissionsAndroid.PERMISSIONS.ACCESS_FINE_LOCATION
            );
            if (permission === PermissionsAndroid.RESULTS.GRANTED) {
                console.log("You can use the location");
                await Geolocation.getCurrentPosition(
                    (position) => {
                        // SENDING CODE
                        this.webviewRef.injectJavaScript(`window.postMessage(${JSON.stringify(position)})`);
                        Alert.alert('latitude:  ', position.coords.latitude.toFixed(2));
                    },
                    (error) => console.log(error),
                );
            } else {
                console.log("Location permission denied")
            }
    }
};

render() {
    return (
        <WebView
            ref={webview => this.webviewRef = webview}
            source={{ uri: 'http://localhost:3000' }}
            style={{ marginTop: 20 }}
            onMessage={(event) => {
                const { data } = event.nativeEvent;
            }}
        />
    );
}
}


// React JS App.js
useEffect(() => {
    window.addEventListener('message', (message) => console.log({ msg: message.data });
}, []);