How to programmatically log out from Facebook SDK 3.0 without using Facebook login/logout button?

The title says it all. I'm using a custom button to fetch the user's facebook information (for "sign up" purposes). Yet, I don't want the app to remember the last registered user, neither the currently logged in person via the Facebook native app. I want the Facebook login activity to pop up each time. That is why I want to log out any previous users programmatically.

How can I do that? This is how I do the login:

private void signInWithFacebook() {

    SessionTracker sessionTracker = new SessionTracker(getBaseContext(), new StatusCallback() 
    {
        @Override
        public void call(Session session, SessionState state, Exception exception) { 
        }
    }, null, false);

    String applicationId = Utility.getMetadataApplicationId(getBaseContext());
    mCurrentSession = sessionTracker.getSession();

    if (mCurrentSession == null || mCurrentSession.getState().isClosed()) {
        sessionTracker.setSession(null);
        Session session = new Session.Builder(getBaseContext()).setApplicationId(applicationId).build();
        Session.setActiveSession(session);
        mCurrentSession = session;
    }

    if (!mCurrentSession.isOpened()) {
        Session.OpenRequest openRequest = null;
        openRequest = new Session.OpenRequest(RegisterActivity.this);

        if (openRequest != null) {
            openRequest.setPermissions(null);
            openRequest.setLoginBehavior(SessionLoginBehavior.SSO_WITH_FALLBACK);

            mCurrentSession.openForRead(openRequest);
        }
    }else {
        Request.executeMeRequestAsync(mCurrentSession, new Request.GraphUserCallback() {
              @Override
              public void onCompleted(GraphUser user, Response response) {
                  fillProfileWithFacebook( user );
              }
            });
    }
}

Ideally, I would make a call at the beginning of this method to log out any previous users.

Solution 1:

Update for latest SDK:

Now @zeuter's answer is correct for Facebook SDK v4.7+:

LoginManager.getInstance().logOut();

Original answer:

Please do not use SessionTracker. It is an internal (package private) class, and is not meant to be consumed as part of the public API. As such, its API may change at any time without any backwards compatibility guarantees. You should be able to get rid of all instances of SessionTracker in your code, and just use the active session instead.

To answer your question, if you don't want to keep any session data, simply call closeAndClearTokenInformation when your app closes.

Solution 2:

This method will help you to logout from facebook programmatically in android

/**
 * Logout From Facebook 
 */
public static void callFacebookLogout(Context context) {
    Session session = Session.getActiveSession();
    if (session != null) {

        if (!session.isClosed()) {
            session.closeAndClearTokenInformation();
            //clear your preferences if saved
        }
    } else {

        session = new Session(context);
        Session.setActiveSession(session);

        session.closeAndClearTokenInformation();
            //clear your preferences if saved

    }

}

Solution 3:

Since Facebook's Android SDK v4.0 (see changelog) you need to execute the following:

LoginManager.getInstance().logOut();

Solution 4:

Here is snippet that allowed me to log out programmatically from facebook. Let me know if you see anything that I might need to improve.

private void logout(){
    // clear any user information
    mApp.clearUserPrefs();
    // find the active session which can only be facebook in my app
    Session session = Session.getActiveSession();
    // run the closeAndClearTokenInformation which does the following
    // DOCS : Closes the local in-memory Session object and clears any persistent 
    // cache related to the Session.
    session.closeAndClearTokenInformation();
    // return the user to the login screen
    startActivity(new Intent(getApplicationContext(), LoginActivity.class));
    // make sure the user can not access the page after he/she is logged out
    // clear the activity stack
    finish();
}