Facebook authentication without login button

@erdomester, @sromku

Facebook launch new sdk version 4.x where Session is deprecated,

There new concept of login as from facebook

LoginManager and AccessToken - These new classes perform Facebook Login

So, Now you can access Facebook authentication without login button as

layout.xml

    <Button
            android:id="@+id/btn_fb_login"
            .../>

MainActivity.java

private CallbackManager mCallbackManager;

@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);

    FacebookSdk.sdkInitialize(this.getApplicationContext());

    mCallbackManager = CallbackManager.Factory.create();

    LoginManager.getInstance().registerCallback(mCallbackManager,
            new FacebookCallback<LoginResult>() {
                @Override
                public void onSuccess(LoginResult loginResult) {
                    Log.d("Success", "Login");

                }

                @Override
                public void onCancel() {
                    Toast.makeText(MainActivity.this, "Login Cancel", Toast.LENGTH_LONG).show();
                }

                @Override
                public void onError(FacebookException exception) {
                    Toast.makeText(MainActivity.this, exception.getMessage(), Toast.LENGTH_LONG).show();
                }
            });

    setContentView(R.layout.activity_main);

    Button btn_fb_login = (Button)findViewById(R.id.btn_fb_login);

    btn_fb_login.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View view) {
              LoginManager.getInstance().logInWithReadPermissions(this, Arrays.asList("public_profile", "user_friends"));
        }
    });

}

Edit

If you don't add the following, it won't work (rightly pointed out by @Daniel Zolnai in comment below):

@Override
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
    super.onActivityResult(requestCode, resultCode, data);
    if(mCallbackManager.onActivityResult(requestCode, resultCode, data)) {
        return;
    }
}

Something like this

private void performFacebookLogin()
{
    Log.d("FACEBOOK", "performFacebookLogin");
    final Session.NewPermissionsRequest newPermissionsRequest = new Session.NewPermissionsRequest(this, Arrays.asList("email"));
    Session openActiveSession = Session.openActiveSession(this, true, new Session.StatusCallback()
    {
        @Override
        public void call(Session session, SessionState state, Exception exception)
        {
            Log.d("FACEBOOK", "call");
            if (session.isOpened() && !isFetching)
            {
                Log.d("FACEBOOK", "if (session.isOpened() && !isFetching)");
                isFetching = true;
                session.requestNewReadPermissions(newPermissionsRequest);
                Request getMe = Request.newMeRequest(session, new GraphUserCallback()
                {
                    @Override
                    public void onCompleted(GraphUser user, Response response)
                    {
                        Log.d("FACEBOOK", "onCompleted");
                        if (user != null)
                        {
                            Log.d("FACEBOOK", "user != null");
                            org.json.JSONObject graphResponse = response.getGraphObject().getInnerJSONObject();
                            String email = graphResponse.optString("email");
                            String id = graphResponse.optString("id");
                            String facebookName = user.getUsername();
                            if (email == null || email.length() < 0)
                            {
                                Logic.showAlert(
                                        ActivityLogin.this,
                                        "Facebook Login",
                                        "An email address is required for your account, we could not find an email associated with this Facebook account. Please associate a email with this account or login the oldskool way.");
                                return;
                            }
                        }
                    }
                });
                getMe.executeAsync();
            }
            else
            {
                if (!session.isOpened())
                    Log.d("FACEBOOK", "!session.isOpened()");
                else
                    Log.d("FACEBOOK", "isFetching");

            }
        }
    });

Actually exactly like that. It works perfectly fine for me.

This worked for me

    import android.os.Bundle;
    import android.app.Activity;
    import android.content.Intent;
    import android.widget.TextView;
    import com.facebook.*;
    import com.facebook.model.*;

    public class MainActivity extends Activity {

      @Override
      public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        // start Facebook Login
        Session.openActiveSession(this, true, new Session.StatusCallback() {

          // callback when session changes state
          @Override
          public void call(Session session, SessionState state, Exception exception) {
            if (session.isOpened()) {

              // make request to the /me API
              Request.newMeRequest(session, new Request.GraphUserCallback() {

                // callback after Graph API response with user object
                @Override
                public void onCompleted(GraphUser user, Response response) {
                  if (user != null) {
                    TextView welcome = (TextView) findViewById(R.id.welcome);
                    welcome.setText("Hello " + user.getName() + "!");
                  }
                }
              }).executeAsync();
            }
          }
        });
      }

      @Override
      public void onActivityResult(int requestCode, int resultCode, Intent data) {
          super.onActivityResult(requestCode, resultCode, data);
          Session.getActiveSession().onActivityResult(this, requestCode, resultCode, data);
      }

    }

if you need to get authorizations after verify that session is open ,add this way:

List<String> permissions = session.getPermissions();             
                 Session.NewPermissionsRequest newPermissionsRequest = new         Session.NewPermissionsRequest(getActivity(), Arrays.asList("read_mailbox"));
                 session.requestNewReadPermissions(newPermissionsRequest);

This simple library can help you: https://github.com/sromku/android-simple-facebook

Just add this library to your project and make the reference from this library to Facebook SDK 3.0.x and add reference from your app to this library.

Then you can login without the LoginButton and do simple actions like publish feeds, get profile/friends, send invite and more.

This is how the login look like:

OnLoginOutListener onLoginOutListener = new SimpleFacebook.OnLoginOutListener()
{

    @Override
    public void onFail()
    {
        Log.w(TAG, "Failed to login");
    }

    @Override
    public void onException(Throwable throwable)
    {
        Log.e(TAG, "Bad thing happened", throwable);
    }

    @Override
    public void onThinking()
    {
        // show progress bar or something to the user while login is happening
        Log.i(TAG, "In progress");
    }

    @Override
    public void onLogout()
    {
        // change the state of the button or do whatever you want
        Log.i(TAG, "Logged out");
    }

    @Override
    public void onLogin()
    {
        // change the state of the button or do whatever you want
        Log.i(TAG, "Logged in");
    }
};

// set login/logut listener
mSimpleFacebook.setLogInOutListener(onLoginOutListener);

// do the login action
mSimpleFacebook.login(MainActivity.this);

Then, in onLogin() callback method you can publish feed like this:

// build feed
Feed feed = new Feed.Builder()
    .setMessage("Clone it out...")
    .setName("Simple Facebook for Android")
    .setCaption("Code less, do the same.")
    .setDescription("The Simple Facebook library project makes the life much easier by coding less code for being able to login, publish feeds and open graph stories, invite friends and more.")
    .setPicture("https://raw.github.com/sromku/android-simple-facebook/master/Refs/android_facebook_sdk_logo.png")
    .setLink("https://github.com/sromku/android-simple-facebook")
    .build();

// publish the feed
mSimpleFacebook.publish(feed);

Hope it can help you.