Demo AppRouter

AppRouter.js

import { Router, Stack, Scene ,Reducer} from 'react-native-router-flux';
import LoginScreen from './LoginScreen'
import HomeView from './HomeView'
import {AsyncStorage} from "react-native";

const USER_KEY = "user-auth";

const reducerCreate = params => {
    const defaultReducer = new Reducer(params);
    return (state, action) => {
        console.log("ACTION:", action);
        return defaultReducer(state, action);
    };
};

const getSceneStyle = () => ({
    backgroundColor: "white",
    shadowOpacity: 1,
    shadowRadius: 3,
});

export default class App extends Component {
    constructor(props, context) {
        super(props, context);
        this.state = {
            logged: false,
            loading: true,
        };
    };


    componentWillMount(){
        self = this;
        isSignedIn().then(data => {
            console.log('New Data' + JSON.parse(data));
            JSON.parse(data) ? this.setState({
                logged: true,
                loading: false,
            }) : this.setState({
                loading: false,
            })
        });
    };
    render() {
            return (
                <Router createReducer={reducerCreate} tintColor="red" getSceneStyle={getSceneStyle}>
                    <Scene key="root" titleStyle={{alignSelf: "center"}} hideNavBar>
                        <Scene key="login" hideNavBar component={LoginScreen} initial={!this.state.logged} title="Login" onExit={()=>console.log("onExit")} type='reset' direction="vertical"/>
                        <Scene key="tabbar" initial={this.state.logged} type='reset' duration={0}>
                            <Scene key="main" tabs tabBarStyle={styles.tabBarStyle} tabBarSelectedItemStyle={styles.tabBarSelectedItemStyle} >
                                <Scene key="home" hideNavBar hideTabBar component={HomeView} title="Home" titleStyle={styles.titleStyle} initial onEnter={onNavigate}/>
                            </Scene>
                        </Scene>
                    </Scene>
    
                </Router>
            )
        }    
 }    
 
 const isSignedIn = () => {
    return new Promise((resolve, reject) => {
        AsyncStorage.getItem(USER_KEY)
            .then(res => {
                if (res !== null) {
                    resolve(true);
                } else {
                    resolve(false);
                }
            })
            .catch(err => reject(err));
    });
};