Using facebook login correctly

In my application on the start page I ask the user to authenticate via Facebook, then I request for some permissions and fetch some information:

LoginButton authButton = (LoginButton) view.findViewById(R.id.authButton);
        authButton.setFragment(this);
        authButton.setReadPermissions(Arrays.asList("user_likes", "user_status"));
        fb = new FacebookMain();

I am able to get all this information, but moving to my next page I want to give a button on my listview and from there a user can post on a friends wall. I followed the HelloFacebook sample and it works like a charm, however in my case when I try to implement it in a fragment it does not work as intended, I dont want the user to login every time he wants to post (I am using an additional permission here -- to post) DO I have to implement all the lifecycly events here, in this fragment? Is there any other or recommended approach to this?

Currently what I am doing is:

my class declaration:

public class FragmentTab1 extends Fragment {

Class level variables:

String FACEBOOK_ID;
String IMAGE_CONTENT;
EditText SEARCH; 
private static final String PERMISSION = "publish_actions";
Session session;
private final String PENDING_ACTION_BUNDLE_KEY = "com.exa.digitalrem:PendingAction";
private PendingAction pendingAction = PendingAction.NONE;
private GraphUser user1;
private UiLifecycleHelper uiHelper;

Functions related to facebook:

private PendingAction pendingAction = PendingAction.NONE;
private GraphUser user1;

private enum PendingAction {
    NONE, POST_PHOTO, POST_STATUS_UPDATE
}



private Session.StatusCallback callback = new Session.StatusCallback() {
    @Override
    public void call(Session session, SessionState state,
            Exception exception) {
        onSessionStateChange(session, state, exception);
    }
}; 

public static boolean isActive() {
    Session session = Session.getActiveSession();
    if (session == null) {
        return false;
    }
    return session.isOpened();
}


private void onSessionStateChange(Session session, SessionState state,
            Exception exception) {
        if (pendingAction != PendingAction.NONE && (exception instanceof FacebookOperationCanceledException || exception instanceof FacebookAuthorizationException)) {
            new AlertDialog.Builder(getActivity()) .setTitle("cancelled").setMessage("NotGranted").setPositiveButton("Ok", null).show();
            pendingAction = PendingAction.NONE;
        } else if (state == SessionState.OPENED_TOKEN_UPDATED) {
            handlePendingAction();
        }
        updateUI();
    }

    private void updateUI() {
        Session session = Session.getActiveSession();
        boolean enableButtons = (session != null && session.isOpened());



        if (enableButtons && user1 != null) {
            //  profilePictureView.setProfileId(user.getId());
            //  greeting.setText(getString(R.string.app_name, user.getFirstName()));
        } else {
            //  profilePictureView.setProfileId(null);
            //  greeting.setText(null);
        }
    }

    @SuppressWarnings("incomplete-switch")
    private void handlePendingAction() {
        PendingAction previouslyPendingAction = pendingAction;
        // These actions may re-set pendingAction if they are still pending, but
        // we assume they
        // will succeed.
        pendingAction = PendingAction.NONE;

    }

In the onCreate:

 uiHelper = new UiLifecycleHelper(getActivity(), callback);
 uiHelper.onCreate(savedInstanceState);


    if (savedInstanceState != null) {
            name = savedInstanceState.getString(PENDING_ACTION_BUNDLE_KEY);
            pendingAction = PendingAction.valueOf(name);
        }

        //===============================================

        Session.openActiveSessionFromCache(getActivity());

        //================================================

This is my facebook post method, I call this on a button click, which is in a listview:

public void postFB(String id) {
        System.out.println("in fb");
        if (isNetworkConnected()) {
            Session session = Session.getActiveSession();
            if (session != null) {
                System.out.println("session not null");
                if (hasPublishPermission()) {
                    //do something

                    WebDialog feedDialog = (new WebDialog.FeedDialogBuilder(
                            getActivity(), Session.openActiveSessionFromCache(getActivity()),
                            params)).setOnCompleteListener(
                                    new OnCompleteListener() {

                                        @Override
                                        public void onComplete(Bundle values,
                                                FacebookException error) {
                                            // frag3.setFbId(null);
                                            // ---------------------------- got to put
                                            // check here
                                            //  onBackPressed();

                                        }
                                    }).build();
                    feedDialog.show();
                } else if (session.isOpened()) {
                    // We need to get new permissions, then complete the action
                    // when we get called back.

                    session.requestNewPublishPermissions(new Session.NewPermissionsRequest(
                            getActivity(), PERMISSION));
                    // do something

                    WebDialog feedDialog = (new WebDialog.FeedDialogBuilder(
                            getActivity(), Session.getActiveSession(),
                            params)).setOnCompleteListener(
                                    new OnCompleteListener() {

                                        @Override
                                        public void onComplete(Bundle values,
                                                FacebookException error) {
                                            // frag3.setFbId(null);
                                            // ---------------------------- got to put
                                            // check here
                                            //onBackPressed();

                                        }
                                    }).build();
                    feedDialog.show();
                }
            }else if(session == null){
                System.out.println("login");
            }
        } else {
            Toast.makeText(getActivity(),
                    "Please check your internet connection", Toast.LENGTH_LONG)
                    .show();
        }
    }

This however does not seem to me a correct approach, is there any better way? Also how do I detect if the user session is expired and prompt the user to login again? The Docs dont seem to reveal the internal functioning of the Login button?

Do not start a new session .... change it in the source code

private Session.StatusCallback callback = new Session.StatusCallback() {
@Override
public void call(Session session, SessionState state,
        Exception exception) {
    onSessionStateChange(session, state, exception);
}
};

Usman Afzal

Add the facebook SDK in your project

Add below lines in AndroidManifest.xml under tag

    <activity android:name="com.facebook.LoginActivity" />

Also Add facebook app id in string.xml

Declare the private members

private boolean isOnCreate;
private List<String> permissions = new ArrayList<String>();
private JSONObject facebookObject;
private ProgressDialog progressDialog;

/** The callback. */
private final com.facebook.Session.StatusCallback callback = new 

com.facebook.Session.StatusCallback() {
@Override
public void call(Session session, SessionState state, Exception exception) {
SignInActivity.this.onSessionStateChange(session, state, exception);
}
};

private void onSessionStateChange(Session session, SessionState state, Exception         exception) {

if (state == SessionState.OPENED) {
if (this.isOnCreate) {
 this.isOnCreate = false;
 return;
     }
     onFacebookLoginDone();
} else if (state == SessionState.CLOSED_LOGIN_FAILED) {
showErrorMessage();
}
}


    @Override
    public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    Session session = Session.getActiveSession();
    if (session == null) {
        session = new Session(this);
        session.closeAndClearTokenInformation();
    }
    Session.setActiveSession(session);
    }

    @Override
    public void onClick(View v) {
    switch (v.getId()) {

    case R.id.btn_fb_login:
        this.loginUsingFacebook();
        break;

    default:
        break;
    }

    }


    @Override
    protected void onActivityResult(int requestCode, int resultCode, Intent data) {

    super.onActivityResult(requestCode, resultCode, data);
    Session.getActiveSession().onActivityResult(this, requestCode, resultCode, data);
    }

    /**
     * Login using facebook.
     */
    private void loginUsingFacebook() {
    isOnCreate = false;
    final Session session = Session.getActiveSession();
    if (session != null && session.getState().equals(SessionState.OPENED)) {
        Session.openActiveSession(this, true, this.callback);
        onFacebookLoginDone();
    } else {
        final Session.OpenRequest temp = new Session.OpenRequest(this);
        this.permissions.clear();
        this.permissions.add(UserClass.EMAIL);
        this.permissions.add("user_location");
        temp.setPermissions(this.permissions);
        temp.setCallback(this.callback);
        session.openForRead(temp);
    }

    }

    /**
     * On facebook login done.
     */
    private void onFacebookLoginDone() {

    final Bundle bundle = new Bundle();
    bundle.putString("fields", "first_name,last_name,id,location,locale,username,email,verified");
    new PerformSignUpOnServer("/me", bundle).execute();
    }

    /**
     * The Class PerformSignUpOnServer.
     */
    private class PerformSignUpOnServer extends AsyncTask<Void, Void, Void> {

    /** The server url. */
    private String serverURL;

    /** The server bundle. */
    private Bundle serverBundle;

    /**
     * Instantiates a new perform sign up on server.
     * 
     * @param url
     *            the url
     * @param bundle
     *            the bundle
     */
    public PerformSignUpOnServer(String url, Bundle bundle) {

        this.serverBundle = bundle;
        this.serverURL = url;
    }

    /*
     * (non-Javadoc)
     * 
     * @see android.os.AsyncTask#onPreExecute()
     */
    @Override
    protected void onPreExecute() {
        progressDialog = ProgressDialog.show(SignInActivity.this, "", "Loading...");
        super.onPreExecute();
    }

    /*
     * (non-Javadoc)
     * 
     * @see android.os.AsyncTask#doInBackground(Params[])
     */
    @Override
    protected Void doInBackground(Void... params) {

        signUpUserOnServer(this.serverURL, this.serverBundle);

        return null;

    }

    /*
     * (non-Javadoc)
     * 
     * @see android.os.AsyncTask#onPostExecute(java.lang.Object)
     */
    @Override
    protected void onPostExecute(Void result) {


    }
    }

    /**
     * Sign up user on server.
     * 
     * @param url
     *            the url
     * @param bundle
     *            the bundle
     */
    private void signUpUserOnServer(String url, Bundle bundle) {
    final Session session = Session.getActiveSession();
    if (session != null && session.isClosed() == false) {
        final Request userInformation = new Request(session, url, bundle, HttpMethod.GET);
        final Response response = userInformation.executeAndWait();
        facebookObject = response.getGraphObject().getInnerJSONObject();
        Log.d("json", facebookObject.toString());
    }
    }

    /**
     * On session state change.
     * 
     * @param state
     *            the state
     */
    private void onSessionStateChange(SessionState state) {

    if (state == SessionState.OPENED) {
        if (isOnCreate) {
        isOnCreate = false;
        return;
        }
        onFacebookLoginDone();
    }
    }

See your log cat with tag "json" you will have a facebook object

来源：https://stackoverflow.com/questions/23660031/using-facebook-login-correctly

标签

android

facebook

android-facebook