Signing out with TabBarIOS

Our final step involves adding a sign out page for the user. Using the TabBarIOS component and the react-native-vector-icons, we will create a tabbed view that allows the user to sign out.

Let's make some modifications for this to happen. We need to first modify App.js so that it does the following functions:

• Imports the TabBarIOS and react-native-vector-icons dependencies
• Returns a TabBarIOS component in its _renderView method if the activity indicator is not spinning
• Add a selectedTab string in the App component's state to track which tab is currently chosen, defaulting to the FeedList component
• Has separate functions to render the FeedList and LoginPage components without navigation
• Passes the LoginPage a callback that executes the _checkLoginStatus method
• Modifies its container style to no longer justify nor align any items to the center

Then, modify the LoginPage component so that its onLogoutFinished callback will execute _checkLoginStatus. Import new dependencies...