Develop Reference

Facebook login: nothing happens after I allow app to access the information

I am trying to implement Facebook Login for Android using these documentation. I am done with initial app configuration and UI changes. I have a login button.
<com.facebook.widget.LoginButton
android:id="#+id/authButton"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_gravity="center_horizontal"
android:layout_marginTop="30dp"
/>
Things are as expected until I click this button. When I click it the application closes and it goes back to Facebook authentication page.
I allow it access my information there. And then nothing happens. The page gets closed and application is already closed.
Why is my application closing?
Where can I catch the response back from authentication page?

There is a lot of work behind connecting with Facebook.
create it According to this guide https://developers.facebook.com/docs/android/login-with-facebook/v2.2
As for your question, this is the part code where you catch the response
private Session.StatusCallback statusCallback =
new SessionStatusCallback();
...
private void onClickLogin() {
Session session = Session.getActiveSession();
if (!session.isOpened() && !session.isClosed()) {
session.openForRead(new Session.OpenRequest(this)
.setPermissions(Arrays.asList("public_profile"))
.setCallback(statusCallback));
} else {
Session.openActiveSession(getActivity(), this, true, statusCallback);
}
}
...
private class SessionStatusCallback implements Session.StatusCallback {
#Override
public void call(Session session, SessionState state, Exception exception) {
// Respond to session state changes, ex: updating the view
}
}

Facebook for Android 3.0 Maintain session

I have a viewpager and ActionBarSherlock. In the menu of the actionbar I placed a button "Log In" that takes me to a login screen (this is the same as the one in the tutorial). This login works fine, every time I open the app, I don't need to login again. What I want is to change this "Log in" menu item to "Log out" when the session is open. But the session is alwasy null. Not the state of the session, but the session itself. Why?
Session session = Session.getActiveSession();
if (session == null) {
} else {
publishStory();
}
What am I missing here? Do I need some other code, or should this be enough?

Because you need to open the active session before you can write Session.getActiveSession(). And don't forget to define session outside:
Session.openActiveSession(getActivity(), true, new StatusCallback() {
#Override
public void call(Session session, SessionState state, Exception exception) {
}
});
session = Session.getActiveSession();
You can learn more about the related openActiveSession method here:
https://developers.facebook.com/docs/reference/android/current/Session

Creating a class for Facebook SDK 3.0 on Android

Is it possible to create a class to encapsulate the Android SDK on android?
i.e - I don't want to clutter my activity with all the FB sessions and stuff, I want to have a class that I can call and it will do the job.
For example,
FacebookSDK sdk = new FacebookSDK();
sdk.publish();
For now I couldn't find a way to do this, without using Fragments or cluttering my activity with the facebook code.
Many Thank!

Its all about session management.
//Check for active session -
Session session = Session.getActiveSession();
// if it doesnt exist create one-
if(session ==null)
session= new Session(getApplicationContext)
// if it is not open open it first
if (!session.isOpened() && !session.isClosed()) {
session.openForRead(new Session.OpenRequest(this)
.setPermissions(Arrays.asList("basic_info"))
.setCallback(statusCallback));
}
else
{
Session.openActiveSession(getActivity(), this, true, statusCallback);
}
// callback listner fires when session state changes
private class SessionStatusCallback implements Session.StatusCallback {
#Override
public void call(Session session, SessionState state, Exception exception) {
//If your session is opened
if(session.isOpened()
publishData(session);
}
Method to publish your request -
public void publishData(Session session)
{
OpenRequest open = new OpenRequest(this);
open.setLoginBehavior(SessionLoginBehavior.SUPPRESS_SSO);
open.setPermissions(Arrays.asList(new String[]{"email", "publish_actions", "user_birthday", "user_hometown"}));
open.setCallback(this);
session.openForPublish(open);
}
publishData defination can also be -
public void publishData(Session session)
{
Bundle params = new Bundle();
params.putByteArray("message", "some message".egtBytes());
params.putByteArray("name", "some name".getBytes());
params.putByteArray("link", "some link".getBytes());
params.putByteArray("description", "Some description".getBytes());
params.putByteArray("picture", "picture.url".getBytes());
Request postToWall = Request.newRestRequest(session,
"/" + pickedUsersId.get(0) + "/feed", params, HttpMethod.POST);
postToWall.setCallback( new Request.Callback()
{
#Override
public void onCompleted(Response response)
{
// get response
Log.e(TAG, response.toString());
}
});
Request.executeBatchAsync(postToWall);
}

In short, no.
Your activity needs to be notifying the Facebook SDK of lifecycle events in order to properly store state and handle the UI flow to and from the Facebook SDK activities.
UILifecycleHelper is an effort to encapsulate this as much as possible.
You may be able to unclutter your code by having all your activities extend some base class (i.e. FBActivity) that makes all the proper calls to UILifecycleHelper, though this only helps if all your activities are interacting with Facebook in a fairly uniform manner.

User is asked for login credentials during reauthorization

I am trying to implement the new Facebook SDK 3.0 into my Android app and I have run into a problem. The problem I am having is that the user is asked to log in again to give publish ("post_to_wall") permissions, even though the user is already logged in, with read permissions. This only happens if the user doesn't have the FB application installed. If he has the FB application installed, then he is only asked to grant the permissions.
This is how I implemented the login:
public void login(Activity activity) {
Session session = Session.getActiveSession();
if (session == null || !session.isOpened()) {
openActiveSession(activity, true, sessionStatusCallback);
}
}
private Session openActiveSession(final Activity activity, final boolean allowLoginUI, final StatusCallback callback) {
return openActiveSession(activity, allowLoginUI, new OpenRequest(activity).setCallback(callback));
}
private Session openActiveSession(final Context context, final boolean allowLoginUI, final OpenRequest openRequest) {
Session session = new Builder(context).setApplicationId(FACEBOOK_APPLICATION_ID).build();
if (SessionState.CREATED_TOKEN_LOADED.equals(session.getState()) || allowLoginUI) {
Session.setActiveSession(session);
session.openForRead(openRequest);
return session;
}
return null;
}
This is the callback's call method:
public void call(final Session session, final SessionState state, final Exception exception) {
if (session.isOpened()) {
if (state.equals(SessionState.OPENED_TOKEN_UPDATED)) {
// code if new permissions have been granted
} else {
// code for login
}
} else if (session.isClosed()) {
// code for user canceled login
} else if (exception != null) {
// code if there were errors during login
}
}
}
This is the code I added to onActivityResult method of the activity that calls the login:
Session.getActiveSession().onActivityResult(activity, requestCode, resultCode, data);
And this is how I ask for new permissions:
Session session = Session.getActiveSession();
if (session != null && session.isOpened()) {
if (DONT_HAVE_PERMISSIONS) {
Session.NewPermissionsRequest newPermissionsRequest = new Session.NewPermissionsRequest(activity,
FACEBOOK_PERMISSIONS).setRequestCode(FACEBOOK_AUTHORIZE_ACTIVITY_CODE);
session.requestNewPublishPermissions(newPermissionsRequest);
}
}
I've tried to find out more about this problem, and I only found out some hints that this is intended, but I haven't found anything concrete.
Is this the default behavior? If so, is there a way around it? Or, perhaps I did something wrong?
Thanks for the help.

Update your SDK version; this issue is resolved in Facebook Android SDK v3.0.1.

Looking at facebooks source code I think it should be possible to start trying to get the permissions directly as both login, and permissions classes derive from the same AuthorizationRequest class, and the AuthorizationRequest class does all the work, like really all the work. The Session.NewPermissionsRequest class just makes some private methods, public in the AuthorizationRequest class and that's it! They might as well give us access to AuthorizationRequest directly. The new facebook API doesn't seem to have any form of "OnFailed/OnSuccess" callbacks, so I end up having a state machine to remember the goal of firing up facebook (login, permissions, get friends list ...), and which step I'm on. If they have done some form of onFailed/onSuccess callbacks it would be simple to make a chain rather than keeping track of a state machine.
I haven't tried what I said. If I do, I'll update the answer. If you try and it works to just fire up Session.NewPermissionsRequest directly without logging in let me know!
Update
I got it working with only asking for credentials once as I explained above.
goto src/com/facebook/Sessions.java
On line 862 you will find
private static Session openActiveSession(Context context, boolean allowLoginUI, OpenRequest openRequest)
make it be a public function and save.
Now instead of creating the Session.NewPermissionsRequest object. Make Session.OpenRequest
permisions = new ArrayList<String>();
permisions.add("user_photos");
permisions.add("friends_photos");
Session.NewPermissionsRequest request = new Session.NewPermissionsRequest(
activity, permisions);
request.setCallback(helper);
if (Session.getActiveSession() != null)
Session.getActiveSession().requestNewReadPermissions(request);
else {
Session.OpenRequest orequest = new Session.OpenRequest(activity);
orequest.setPermissions(permisions);
orequest.setCallback(helper);
// its now public so you can call it
Session.openActiveSession(act, true, request);
}
Now make sure you do set a callback, for one important reason
#Override
public void call(Session session, SessionState state, Exception exception) {
if (state.isClosed()) {
// we are doing unofficial stuff so we loose guarantees.
// Set the active session to null if we logout or user cancels
// logging in. If you don't do this, the second time it will result
// in a crash.
Session.setActiveSession(null);
}
}
Now it will ask for all permissions directly and login in one go.

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.

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.

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
}
}

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

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();
}

Since Facebook's Android SDK v4.0 you need to execute the following:
LoginManager.getInstance().logOut();
This is not sufficient. This will simply clear cached access token and profile so that AccessToken.getCurrentAccessToken() and Profile.getCurrentProfile() will now become null.
To completely logout you need to revoke permissions and then call LoginManager.getInstance().logOut();. To revoke permission execute following graph API -
GraphRequest delPermRequest = new GraphRequest(AccessToken.getCurrentAccessToken(), "/{user-id}/permissions/", null, HttpMethod.DELETE, new GraphRequest.Callback() {
#Override
public void onCompleted(GraphResponse graphResponse) {
if(graphResponse!=null){
FacebookRequestError error =graphResponse.getError();
if(error!=null){
Log.e(TAG, error.toString());
}else {
finish();
}
}
}
});
Log.d(TAG,"Executing revoke permissions with graph path" + delPermRequest.getGraphPath());
delPermRequest.executeAsync();

Session class has been removed on SDK 4.0. The login magement is done through the class LoginManager. So:
mLoginManager = LoginManager.getInstance();
mLoginManager.logOut();
As the reference Upgrading to SDK 4.0 says:
Session Removed - AccessToken, LoginManager and CallbackManager classes supercede and replace functionality in the Session class.

Yup, As #luizfelippe mentioned Session class has been removed since SDK 4.0. We need to use LoginManager.
I just looked into LoginButton class for logout. They are making this kind of check. They logs out only if accessToken is not null. So, I think its better to have this in our code too..
AccessToken accessToken = AccessToken.getCurrentAccessToken();
if(accessToken != null){
LoginManager.getInstance().logOut();
}

private Session.StatusCallback statusCallback = new SessionStatusCallback();
logout.setOnClickListener(new OnClickListener() {
#Override
public void onClick(View arg0) {
Session.openActiveSession(this, true, statusCallback);
}
});
private class SessionStatusCallback implements Session.StatusCallback {
#Override
public void call(Session session, SessionState state,
Exception exception) {
session.closeAndClearTokenInformation();
}
}

Facebook provides two ways to login and logout from an account. One is to use LoginButton and the other is to use LoginManager. LoginButton is just a button which on clicked, the logging in is accomplished. On the other side LoginManager does this on its own. In your case you have use LoginManager to logout automatically.
LoginManager.getInstance().logout() does this work for you.