Prevent for user to access "Auth Loading Screen" on android - react-native

Question

In my app (and most likely like any other app) I have a loading screen which checks if the user is either logged in or not. Thing is that the user on android right now has the possibility of returning to that screen if the "back" button is pressed. How is it possible for me to avoid for the user doing that?
This is what I have on my code:
const loadingStack = createSwitchNavigator({
Loading: {
screen: Loading
}
}, {
defaultNavigationOptions: {
unmountOnBlur: true,
headerMode: 'none',
gestureEnabled: false
}
}
);
export default createAppContainer(
createStackNavigator({
Loading: loadingStack,
App: {
screen: AppTabNavigator,
navigationOptions: {
gestureEnabled: false,
},
},
Auth: {
screen: AuthStack,
},
...

Answer 1

I see two solutions:
Change your navigation and opt for a switch navigation instead.
createAppContainer(
createSwitchNavigator(
{
Loading: {
screen: Loading,
navigationOptions: {
headerMode: 'none',
}
},
App: {
screen: AppTabNavigator,
navigationOptions: {
gestureEnabled: false
}
},
Auth: {
screen: AuthStack
}
}
)
)
If you want to "enjoy" the animations of the StackNavigator, when you navigate from your Loading to your App, you replace your current view with your new view.
//Example on your Loading Screen
this.props.navigation.replace({ routeName: "App" })
This will replace your Loading Screen view with your App "View", when you go back, you will not be redirected to the Loading Screen anymore because it is no longer in the stack, it has been replaced by App.
EDIT (In response to the comment because it's too long):
In this case, if you want to make a special backButton management on the Home you can use the React Native BackHandler.
For example, if you want nothing to happen when you click on the backButton, add an eventListener that returns true no matter what:
import { BackHandler } from 'react-native'
...
componentDidMount() {
this.backHandler = BackHandler.addEventListener('hardwareBackPress', () => true)
}
componentWillUnmount(){
this.backHandler.remove()
}
Otherwise, if you want the app to quit, for example:
this.backHandler = BackHandler.addEventListener('hardwareBackPress', () => BackHandler.exitApp())