How to implement signOut once signed in with Cognito/UserPool on Android

Question

Looking for some help on implementing the signOut() function to allow the user to sign out of the app.

I have implemented the code found here: https://docs.aws.amazon.com/aws-mobile/latest/developerguide/add-aws-mobile-user-sign-in.html

I was able to get the AWS sign-in screen working and i can see the new user created in Cognito as well, however when I try implemented a sign-out button to take me back to the previous intent, it keeps bouncing back. I did some reading around and found that user will always stay signed in.

Below is the code I have for the AuthenticatorActivity:

import com.amazonaws.mobile.auth.ui.SignInUI;
import com.amazonaws.mobile.client.AWSMobileClient;
import com.amazonaws.mobile.client.AWSStartupHandler;
import com.amazonaws.mobile.client.AWSStartupResult;


public class AuthenticatorActivity extends AppCompatActivity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_authenticator);

        // Add a call to initialize AWSMobileClient
        AWSMobileClient.getInstance().initialize(this, new AWSStartupHandler() {
            @Override
            public void onComplete(AWSStartupResult awsStartupResult) {
                SignInUI signin = (SignInUI) AWSMobileClient.getInstance().getClient(AuthenticatorActivity.this, SignInUI.class);
                signin.login(AuthenticatorActivity.this, MainActivity.class).execute();
            }
        }).execute();
    }
}

Once user enters in details to sign up and then signs in, the next activity/intent displayed also has the below sign-out button visible.

Below code is what I have when the sign out button is pressed (in another Activity):

/** called when the user taps the send button */
    public void signOutOfApp(View view) {
        Intent intent = new Intent(this, AuthenticatorActivity.class);
        startActivity(intent);
    }

Could someone please help me out in suggesting how I could get this to work? The AuthenticatorActivity doesn't appear to have anything to indicate where it is passing/storing the new user details and when i get to the next activity/intent, I am not sure how i can call/get the user details to pass that to the signout method. Please help guide me here! Thanks in advance!

Answer 1

The signOut method is available through the IdentityManager class. The following will let you invoke signOut. Since signOut is asynchronous, you may want to register a callback with the IdentityManager in order to get a callback when the user has signed out successfully.

Register the callback for getting notified of the sign-in state change:

IdentityManager.getDefaultIdentityManager().addSignInStateChangeListener(new SignInStateChangeListener() {
                @Override
                public void onUserSignedIn() {
                    Log.d(LOG_TAG, "User Signed In");
                }

                @Override
                public void onUserSignedOut() {
                    Log.d(LOG_TAG, "User Signed Out");
                }
});

To invoke signOut:

IdentityManager.getDefaultIdentityManager().signOut();

How does AWSMobileClient interact with the IdentityManager ?

AWSMobileClient creates the IdentityManager object and set the object as the default IdentityManager . Since IdentityManager is a singleton, you can use IdentityManager.getDefaultIdentityManager() anywhere from your app.

Answer 2

as for Kotlin since I can login using AWS, where do I add this in my nextActivity and the signout also IdentityManager.getDefaultIdentityManager().signOut();

IdentityManager.getDefaultIdentityManager().addSignInStateChangeListener(
    object : SignInStateChangeListener() {
        override fun onUserSignedIn() {
            Log.d(TAG, "User signed in");
        }

        override fun onUserSignedOut() {
            Log.d(TAG, "User signed out");
        }
    }
)