How to check if the user is already logged in?

Question

I am complete new to react-native and Facebook sdk

So I have followed the tutorial given here and everything works fine, the user

Answer 1

You need to check if currentAccessToken is valid in the beginning somewhere appropriate when your app is started. If it returns null, you need to refresh the token and if refresh token is expired, redirect user to loginpage.

AccessToken.getCurrentAccessToken().then(
            (data) => {console.log(data);} //Refresh it every time
        );