Facebook Login for Android - Quickstart

The Facebook SDK for Android enables people to sign into your app with Facebook Login. When people log into your app with Facebook they can grant permissions to your app so you can retrieve information or perform actions on Facebook on their behalf.

For an example project that illustrates how to integrate Facebook Login into an Android app, see the FBLoginSample on GitHub.

Follow the steps below to add Facebook Login to your app.

1. Login

Please log in to Facebook to create apps or register as a developer.

Log into Facebook

2. Download the Facebook App

Download the Facebook app by clicking the button below.

Download Facebook for Android

3. Integrate the Facebook SDK

The Facebook Login SDK for Android is a component of the Facebook SDK for Android. To use the Facebook Login SDK in your project, make it a dependency in Maven, or download it. To support the changes in Android 11, use SDK version 8.1 or higher.

Using Maven

In your project, open your_app > Gradle Scripts > build.gradle (Project) make sure the following repository is listed in the buildscript { repositories {}}:
```
mavenCentral() 
```
In your project, open your_app > Gradle Scripts > build.gradle (Module: app) and add the following implementation statement to the dependencies{} section to depend on the latest version of the Facebook Login SDK:
```
 implementation 'com.facebook.android:facebook-login:latest.release'
```
Build your project.

4. Edit Your Resources and Manifest

If you use version 5.15 or later of the Facebook SDK for Android, you don't need to to add an activity or intent filter for Chrome Custom Tabs. This functionality is included in the SDK.

After you integrate Facebook Login, certain App Events are automatically logged and collected for Events Manager, unless you disable Automatic App Event Logging. In particular, when launching an app in Korea, please note that Automatic App Event Logging can be disabled. For details about what information is collected and how to disable automatic app event logging, see Automatic App Event Logging.

Create strings for your Facebook app ID and for those needed to enable Chrome Custom Tabs. Also, add FacebookActivity to your Android manifest.

Open your /app/res/values/strings.xml file.
Add string elements with the names facebook_app_id, fb_login_protocol_scheme and facebook_client_token, and set the values to your App ID and Client Token. For example, if your app ID is 1234 and your client token is 56789 your code looks like the following:
```
<string name="facebook_app_id">1234</string>
<string name="fb_login_protocol_scheme">fb1234</string>
<string name="facebook_client_token">56789</string>
```
Open the /app/manifest/AndroidManifest.xml file.

Add meta-data elements to the application element for your app ID and client token:

<application android:label="@string/app_name" ...>
    ...
   	<meta-data android:name="com.facebook.sdk.ApplicationId" android:value="@string/facebook_app_id"/>
   	<meta-data android:name="com.facebook.sdk.ClientToken" android:value="@string/facebook_client_token"/>
    ...
</application>

Add an activity for Facebook, and an activity and intent filter for Chrome Custom Tabs inside your application element:

    <activity android:name="com.facebook.FacebookActivity"
        android:configChanges=
                "keyboard|keyboardHidden|screenLayout|screenSize|orientation"
        android:label="@string/app_name" />
    <activity
        android:name="com.facebook.CustomTabActivity"
        android:exported="true">
        <intent-filter>
            <action android:name="android.intent.action.VIEW" />
            <category android:name="android.intent.category.DEFAULT" />
            <category android:name="android.intent.category.BROWSABLE" />
            <data android:scheme="@string/fb_login_protocol_scheme" />
        </intent-filter>
    </activity>

Add a uses-permission element to the manifest after the application element:
```
<uses-permission android:name="android.permission.INTERNET"/>
```
(Optional) To opt out of the Advertising ID Permission, add a uses-permission element to the manifest after the application element:
```
<uses-permission android:name="com.google.android.gms.permission.AD_ID" tools:node="remove"/>
        
```

You may directly set the auto-logging of App Events to “true” or “false” by setting the AutoLogAppEventsEnabled flag in the AndroidManifest.xml file.

Build your project.

5. Associate Your Package Name and Default Class with Your App

You need to login to complete this step.

6. Provide the Development and Release Key Hashes for Your App

You need to login to complete this step.

7. Enable Single Sign On for Your App

You need to login to complete this step.

8. Add the Facebook Login Button

The simplest way to add Facebook Login to your app is to add LoginButton from the SDK. The LoginButton is a UI element that wraps functionality available in the LoginManager. When someone clicks on the button, the login is initiated with the permissions set in the LoginManager. Facebook Login requires advanced public_profile permission, to be used by external users. The button follows the login state, and displays the correct text based on someone's authentication state.

To add the Facebook Login button, first add it to your layout XML file:

<com.facebook.login.widget.LoginButton
    android:id="@+id/login_button"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_gravity="center_horizontal"
    android:layout_marginTop="30dp"
    android:layout_marginBottom="30dp" />

9. Register a Callback

Now create a callbackManager to handle login responses by calling CallbackManager.Factory.create.

callbackManager = CallbackManager.Factory.create();

If you are adding the button to a Fragment you must also update your activity to use your fragment. You can customize the properties of Login button and register a callback in your onCreate() or onCreateView() method. Properties you can customize includes LoginBehavior, DefaultAudience, ToolTipPopup.Style and permissions on the LoginButton. For example:

      
    private static final String EMAIL = "email";
      
    loginButton = (LoginButton) findViewById(R.id.login_button);
    loginButton.setReadPermissions(Arrays.asList(EMAIL));
    // If you are using in a fragment, call loginButton.setFragment(this);    

    // Callback registration
    loginButton.registerCallback(callbackManager, new FacebookCallback<LoginResult>() {
        @Override
        public void onSuccess(LoginResult loginResult) {
            // App code
        }

        @Override
        public void onCancel() {
            // App code
        }

        @Override
        public void onError(FacebookException exception) {
            // App code
        }
    });

To respond to a login result, you need to register a callback with either LoginManager or LoginButton. If you register the callback with LoginButton, don't need to register the callback on Login manager.

You add the LoginManager callback to your activity or fragment's onCreate() method:

    callbackManager = CallbackManager.Factory.create();      
      
    LoginManager.getInstance().registerCallback(callbackManager,
            new FacebookCallback<LoginResult>() {
                @Override
                public void onSuccess(LoginResult loginResult) {
                    // App code
                }

                @Override
                public void onCancel() {
                     // App code
                }

                @Override
                public void onError(FacebookException exception) {
                     // App code   
                }
    });

If login succeeds, the LoginResult parameter has the new AccessToken, and the most recently granted or declined permissions.

You don't need a registerCallback for login to succeed, you can choose to follow current access token changes with the AccessTokenTracker class described below.

Finally, in your onActivityResult method, call callbackManager.onActivityResult to pass the login results to the LoginManager via callbackManager.

If you are using AndroidX activities or fragments, you don't have to override onActivityResult.

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

Every activity and fragment that you integrate with the FacebookSDK Login or Share should forward onActivityResult to the callbackManager.

Your app can only have one person at a time logged in, and LoginManager sets the current AccessToken and Profile for that person. The FacebookSDK saves this data in shared preferences and sets at the beginning of the session. You can see if a person is already logged in by checking AccessToken.getCurrentAccessToken() and Profile.getCurrentProfile().

You can load AccessToken.getCurrentAccessToken with the SDK from cache or from an app book mark when your app launches from a cold start. You should check its validity in your Activity's onCreate method:

AccessToken accessToken = AccessToken.getCurrentAccessToken();
boolean isLoggedIn = accessToken != null && !accessToken.isExpired();

Then you can later perform the actual login, such as in a custom button's OnClickListener:

      
LoginManager.getInstance().logInWithReadPermissions(this, Arrays.asList("public_profile"));

11. Enable Express Login

Express login logs people in with their Facebook account across devices and platform. If a person logs into your app on Android and then changes devices, express login logs them in with their Facebook account, instead of asking for them to select a login method. This avoid creating duplicate accounts or failing to log in at all. To support the changes in Android 11, first add the following code to the queries element in your /app/manifest/AndroidManifest.xml file.

  
<queries>
  <package android:name="com.facebook.katana" />
</queries>

The following code shows how to enable express login.

LoginManager.getInstance().retrieveLoginStatus(this, new LoginStatusCallback() {
    @Override
    public void onCompleted(AccessToken accessToken) {
        // User was previously logged in, can log them in directly here.
        // If this callback is called, a popup notification appears that says
        // "Logged in as <User Name>"
    }
    @Override
    public void onFailure() {
        // No access token could be retrieved for the user
    }
    @Override
    public void onError(Exception exception) {
        // An error occurred
    }
});