Question

I followed this tutorial http://www.androidhive.info/2012/03/android-facebook-connect-tutorial/ to connect Facebook to my Android application. Instead of having many buttons, I have a button that will be used for both login and logout.

1) The first time I run the class, I could login and then logout successfully. And when I click on the same button to login again, the login page would not appear, however the Toast text “LOGGING IN” appear, which is after loginToFacebook() function in my if-else. Hence, I assume, it should have run the facebook login page like the first time I run the class. But the login page does not appear.

What did I do wrong? And what should I do?

2) And how do I display the username in String fbLoggedIn after logged in instead of the text “CONNECTED!!” ?

public class FacebookActivity extends Activity{

private static String APP_ID = "";
private Facebook facebook;
private AsyncFacebookRunner mAsyncRunner;
String FILENAME = "AndroidSSO_data";
private SharedPreferences mPrefs;
private Button backButton;
private String name = "CONNECTED!!";

@Override
protected void onCreate(Bundle savedInstanceState) {
    // TODO Auto-generated method stub
    super.onCreate(savedInstanceState);
    setContentView(R.layout.settings_share);

    facebook = new Facebook(APP_ID);
    mAsyncRunner = new AsyncFacebookRunner(facebook);

    RelativeLayout fbButton = (RelativeLayout) findViewById(R.id.fbLayout);
    fbButton.setOnClickListener(new View.OnClickListener() {

        @Override
        public void onClick(View v) {
            // TODO Auto-generated method stub
            if (!facebook.isSessionValid())
            {
            System.out.println("Not Connected. Clicked and Login.");    
            loginToFacebook();
            Toast.makeText(getApplicationContext(), "LOGGING IN", Toast.LENGTH_LONG).show();}

            else
            {
            System.out.println("Connected. Logged Out.");   
            logoutFromFacebook();
            Toast.makeText(getApplicationContext(), "LOGGED OUT", Toast.LENGTH_LONG).show();}
        }
    });     
}

public void loginToFacebook() {
    mPrefs = getPreferences(MODE_PRIVATE);
    String access_token = mPrefs.getString("access_token", null);
    long expires = mPrefs.getLong("access_expires", 0);

    if (access_token != null) {
        facebook.setAccessToken(access_token);
    }

    if (expires != 0) {
        facebook.setAccessExpires(expires);
    }

    if (!facebook.isSessionValid()) {   

        facebook.authorize(this, new String[] { "email", "publish_stream" }, new DialogListener() {

                    @Override
                    public void onCancel() {
                        // Function to handle cancel event
                    }

                    @Override
                    public void onComplete(Bundle values) {
                        // Function to handle complete event
                        // Edit Preferences and update facebook acess_token
                        SharedPreferences.Editor editor = mPrefs.edit();
                        editor.putString("access_token", facebook.getAccessToken());
                        editor.putLong("access_expires", facebook.getAccessExpires());
                        editor.commit();   

                        TextView fbUser = (TextView) findViewById(R.id.fbUser);
                        fbUser.setVisibility(View.VISIBLE);
                        String fbLoggedIn = name;
                        fbUser.setText(fbLoggedIn); 
                        Toast.makeText(getApplicationContext(), "LOGGED IN AS " + name, Toast.LENGTH_LONG).show();         
                    }

                    @Override
                    public void onError(DialogError error) {
                        // Function to handle error
                    }

                    @Override
                    public void onFacebookError(FacebookError fberror) {
                        // Function to handle Facebook errors
                    }

                });
    }
}

public void getProfileInformation() {
    mAsyncRunner.request("me", new RequestListener() {
        @Override
        public void onComplete(String response, Object state) {
            Log.d("Profile", response);
            String json = response;
            try {
                JSONObject profile = new JSONObject(json);
                // getting name of the user
                final String name = profile.getString("name");
                // getting email of the user
                final String email = profile.getString("email");

                runOnUiThread(new Runnable() {

                    @Override
                    public void run() {
                        Toast.makeText(getApplicationContext(), "Name: " + name + "\nEmail: " + email, Toast.LENGTH_LONG).show();
                    }

                });

            } catch (JSONException e) {
                e.printStackTrace();
            }
        }

        @Override
        public void onIOException(IOException e, Object state) { }

        @Override
        public void onFileNotFoundException(FileNotFoundException e, Object state) { }

        @Override
        public void onMalformedURLException(MalformedURLException e, Object state) { }

        @Override
        public void onFacebookError(FacebookError e, Object state) { }
    });
}

//logout from Facebook
public void logoutFromFacebook() {
    mAsyncRunner.logout(this, new RequestListener() {
        @Override
        public void onComplete(String response, Object state) {
            Log.d("Logout from Facebook", response);
            if (Boolean.parseBoolean(response) == true) {
                // User successfully Logged out
         }

        }

        @Override
        public void onIOException(IOException e, Object state) { }

        @Override
        public void onFileNotFoundException(FileNotFoundException e, Object state) { }

        @Override
        public void onMalformedURLException(MalformedURLException e, Object state) { }

        @Override
        public void onFacebookError(FacebookError e, Object state) { }
    });
 }

Just to be clearer, I set my if-else like this (extracted from the complete codes above).

    RelativeLayout fbButton = (RelativeLayout) findViewById(R.id.fbLayout);
    fbButton.setOnClickListener(new View.OnClickListener() {

        @Override
        public void onClick(View v) {
            // TODO Auto-generated method stub
            if (!facebook.isSessionValid())
            {
            System.out.println("Not Connected. Clicked and Login.");    
            loginToFacebook();
            Toast.makeText(getApplicationContext(), "LOGGING IN", Toast.LENGTH_LONG).show();}

            else
            {
            System.out.println("Connected. Logged Out.");   
            logoutFromFacebook();
            Toast.makeText(getApplicationContext(), "LOGGED OUT", Toast.LENGTH_LONG).show();}
        }
    }); 

Answer 1

This is the behavior that Facebook wants you to take with their API.Your login method checks to see if you have already signed in once and that the facebook session is active. If the session is active then it sets the properties of the facebook object and connects it behind the sences so that the login page does not show again.

So you’re not doing anything wrong, it’s suppose to happen this way.