Prop for alerting the user before exiting app

README.md

@@ -125,6 +125,7 @@ The **`<Router />`** object used to initialize the navigation can take the follo
 - `customAction`: A special callback prop for your action buttons (this can be handy for triggering a side menu for example). The action gets triggered from your custom `leftCorner` or `rightCorner` components by calling `this.props.customAction("someActionName")` from them. It is then picked up like this: `<Router customAction={this.doSomething} />`.
 - `hideNavigationBar`: Hide the navigation bar, always
 - `handleBackAndroid` (Boolean value): Apply a listener to the native back button on Android. On click, it will go to the previous route until it reach the first scene, then it will exit the app.
+- `alertAndroidExit` (Boolean value): Alert the user if the Android back button is about to exit them from the app.
 - `statusBarProps`: Default StatusBar props, please refer to [StatusBar Docs](https://facebook.github.io/react-native/docs/statusbar.html#content). (Android) If `backgroundColor` isn't provided, it will take the same color as defined in `headerStyle`.
 - `sceneConfig`: Default animation to be used in case no `sceneConfig` is provided by the `toRoute` function. More details and possible parameters are in the `toRoute` documentation below. Defaults to `Navigator.SceneConfigs.FloatFromRight`.
 
@@ -170,7 +171,7 @@ The **`this.props.toRoute()`** callback prop takes one parameter (a JavaScript o
       const {
         text,
         user,
-      } = this.props.data;  
+      } = this.props.data;
   ```
 
 The **`this.props.replaceRoute`** function takes in an object that can contain the same keys as `toRoute()`. The difference is that instead of adding a route to your stack, it replaces the route

components/NavBarContainer.js

@@ -1,5 +1,6 @@
 import React, { PropTypes } from 'react';
 import {
+  Alert,
   BackAndroid,
   Platform,
   StyleSheet,
@@ -17,6 +18,7 @@ const propTypes = {
   currentRoute: PropTypes.object.isRequired,
   customAction: PropTypes.func,
   handleBackAndroid: PropTypes.bool,
+  alertAndroidExit: PropTypes.bool,
   goToFirstRoute: PropTypes.func.isRequired,
   leftProps: PropTypes.object,
   navigator: PropTypes.object.isRequired,
@@ -70,10 +72,19 @@ class NavBarContainer extends React.Component {
       BackAndroid.addEventListener('hardwareBackPress', () => {
         if (this.props.currentRoute.index > 0) {
           this.goBack();
-          return true;
+        } else {
+          console.log('dsa')
+          console.log(this.props.alertAndroidExit)
+          console.log('dsa')
+          if (this.props.alertAndroidExit) {
+            Alert.alert('Leaving Current App', 'Are you sure you want to exit?', [
+              { text: 'Cancel', style: 'cancel' },
+              { text: 'Yes', onPress: () => BackAndroid.exitApp() }
+            ])
+          }
         }
 
-        return false;
+        return true;
       });
     }
   }

index.js

@@ -23,6 +23,7 @@ const propTypes = {
   customAction: PropTypes.func,
   firstRoute: PropTypes.object.isRequired,
   handleBackAndroid: PropTypes.bool,
+  alertAndroidExit: PropTypes.bool,
   headerStyle: View.propTypes.style,
   hideNavigationBar: PropTypes.bool,
   noStatusBar: PropTypes.bool,
@@ -380,6 +381,7 @@ class Router extends React.Component {
           titleProps={this.state.titleProps}
           customAction={this.customAction}
           handleBackAndroid={this.props.handleBackAndroid}
+          alertAndroidExit={this.props.alertAndroidExit}
         />
       );
     }