React Native - How to manage the native back button with Drawer Navigation

Question

I recreated the Drawer Navigation following this code: https://github.com/mariodev12/react-native-menu-drawer-navigator

Everything works correctly but now I do not know how to handle the native button to go back .. I would like to always return to the previous page, but if you press twice in the home exit the app.

This is my Code:

App.js

import React from 'react';
import {StackNavigator} from 'react-navigation';
import DrawerStack from './src/stacks/drawerStack';

const Navigator = StackNavigator({
    drawerStack: {screen: DrawerStack}
}, {
    headerMode: 'none',
    initialRouteName: 'drawerStack'
})

export default Navigator

drawerStack.js

import React from 'react'
import {StackNavigator, DrawerActions} from "react-navigation";
import {Text, View, TouchableOpacity} from 'react-native';
import Home from "../components/home";
import DrawerScreen from "./drawerScreen";

const DrawerNavigation = StackNavigator({
    DrawerStack: {screen: DrawerScreen}
}, {
    headerMode: 'float',
    navigationOptions: ({navigation}) => ({
        headerStyle: {
            backgroundColor: 'rgb(255,45,85)',
            paddingLeft: 10,
            paddingRight: 10
        },
        title: 'Home',
        headerTintColor: 'white',
        headerLeft: <View>
            <TouchableOpacity
                onPress={() => {
                    if (navigation.state.isDrawerOpen === false) {
                        navigation.dispatch(DrawerActions.openDrawer());
                    } else {
                        navigation.dispatch(DrawerActions.closeDrawer());
                    }
                }}>
                <Text>Menu</Text>
            </TouchableOpacity>
        </View>
    })
})

export default DrawerNavigation;

drawerScreen.js

import {DrawerNavigator} from 'react-navigation'
import Home from '../components/home';
import Login from '../components/login';
import Contacts from '../components/contacts';
import News from '../components/news';

const DrawerScreen = DrawerNavigator({
    Home: {screen: Home},
    Login: {screen: Login},
    Contacts: {screen: Contacts},
    News: {screen: News}
}, {
    headerMode: 'none',
    initialRouteName: 'Home'
})

export default DrawerScreen;

news.js "Example of one page"

import React from "react";
import {Text, View} from 'react-native';

export default class News extends React.Component {
    render() {

        return (
            <View>
                <Text> Here Leave the News!! </Text>
            </View>
        );
    }
}

Now, how do I insert the back button in the header instead of the classic menu (DrawerStack) for only the 'News.js' page?

Answer 1

In Android you have to handle back button actions by yourself with BackHandler from react-native.

First of all

import { BackHandler } from 'react-native';

in ComponentDidMount add an event listener to listen for backpress:

componentDidMount() {
    BackHandler.addEventListener("hardwareBackPress", this.onBackPress);
}

in ComponentwillUnmount make sure you remove the listener:

componentWillUnmount() {
    BackHandler.removeEventListener("hardwareBackPress", this.onBackPress);
}

then

 onBackPress = () => {

     //inside here do what you want with single back button
 }

Checkout this link too: https://reactnavigation.org/docs/en/drawer-based-navigation.html

If you want to go back to previous Screen with back button drawer navigation isn't for you and you should try to use Stack Navigator.