How to Authenticate your Android Users Using Phone or Email

In this tutorial I will show how to use Facebook’s Account Kit Tool to allow users to log in or sign up using their phone number or email. You can find the completed project on Github.

After creating your project, please make sure that you add your Application to the Facebook’s Developers console and obtain your APP ID.

Once your Android Studio project has been set up, go to your Project/build.gradle and add mavenCentral() inside the repositories{ }

Also open your app/build.gradle file and add the Account Kit dependency:

compile 'com.facebook.android:account-kit-sdk:4.20.0'

Android Manifest file and Strings

Inside the strings.xml file, add the following IDs:

    <string name="facebook_app_id">YOUR_FACEBOOK_APP_ID</string>
    <string name="ACCOUNT_KIT_CLIENT_TOKEN">YOUR_ACCOUNT_KIT_CLIENT_TOKEN</string>
    <string name="ak_login_protocol_scheme">akYOUR_FACEBOOK_APP_ID</string>

Next, we need to declare the required permissions, activities and meta datas inside the AndroidManifest.xml: Since this application needs the Internet to perform the Phone or Email login, make sure you add the INTERNET permission on top of the Manifest file.

<uses-permission android:name="android.permission.INTERNET"/>

To properly configure our application and connect with the Facebook dashboard, we need to add the following meta data:

<meta-data android:name="com.facebook.accountkit.ApplicationName"
            android:value="@string/app_name" />
<meta-data android:name="com.facebook.sdk.ApplicationId"
    android:value="@string/facebook_app_id" />
<meta-data android:name="com.facebook.accountkit.ClientToken"
    android:value="@string/ACCOUNT_KIT_CLIENT_TOKEN" />
<meta-data android:name="com.facebook.accountkit.FacebookAppEventsEnabled"
    android:value="false"/>

Inside the <application> tags, we need to declare the Email Redirect Activity.

<activity
    android:name="com.facebook.accountkit.ui.AccountKitEmailRedirectActivity">
            <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/ak_login_protocol_scheme" />
            </intent-filter>
 </activity>

This activity, detects when you click on an Account Kit kind of link or URL placed inside the Email body and launches the Application. That occurs when the user has confirmed the received email about Email logging in using Account Kit.

In this tutorial we are going to use a very simple layout. It contains only three buttons, and you can find its code below:

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical"
    android:gravity="center"
    tools:context="com.example.theodhor.fbaccountkit.MainActivity">

    <Button
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:onClick="emailLogin"
        android:text="Email Login"
        android:textAllCaps="false"/>

    <Button
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="Phone Login"
        android:textAllCaps="false"
        android:onClick="phoneLogin"/>

    <Button
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="Logout"
        android:textAllCaps="false"
        android:onClick="logout"/>

</LinearLayout>

Each one of the first two buttons will open a new view, Phone number login type or Email, depending on the case. The third button clears the stored sessions.

Login with email or phone

To begin with, we will declare two global variables as below:

public static int APP_REQUEST_CODE = 99;
public static final String TAG = "MainActivity";

Each one of the buttons declared inside the xml has a function as a parameter of the onClick attribute. So we need a public void emailLogin(View view) method inside our activity.

public void emailLogin(@Nullable View view) {
    final Intent intent = new Intent(this, AccountKitActivity.class);
    AccountKitConfiguration.AccountKitConfigurationBuilder configurationBuilder = new AccountKitConfiguration.AccountKitConfigurationBuilder(
            LoginType.EMAIL,AccountKitActivity.ResponseType.TOKEN); // or .ResponseType.CODE
    UIManager uiManager = new SkinManager(
            LoginType.EMAIL,
            SkinManager.Skin.CLASSIC,
            (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M ? getResources().getColor(R.color.colorPrimary,null):getResources().getColor(R.color.colorPrimary)),
            R.drawable.background,
            SkinManager.Tint.BLACK,
            0.55
    );
    configurationBuilder.setUIManager(uiManager);
    intent.putExtra(AccountKitActivity.ACCOUNT_KIT_ACTIVITY_CONFIGURATION,configurationBuilder.build());
    startActivityForResult(intent, APP_REQUEST_CODE);
}

This method will open the Email Login view. The @Nullable annotation allows us to call the same method even with a null parameter.

Its UI will be determined by the UIManager object. Using this object, you can customize its skin type, primary color, background image, tint color and tint intensity.

To start the Phone Login type activity, just set the LoginType.EMAIL to LoginType.PHONE

After the Account Kit activity has finished, it will return an AccountKit Account with a AccessToken at the same time. To get this account and access token, we need to Override the onActivityResult method. Its code is below:

@Override
    protected void onActivityResult(final int requestCode,final int resultCode,final Intent data) {
        super.onActivityResult(requestCode, resultCode, data);
        if (requestCode == APP_REQUEST_CODE && resultCode == RESULT_OK) {
            getCurrentAccount();
        }
    }

The getCurrentAccount(); method:

private void getCurrentAccount(){
        AccessToken accessToken = AccountKit.getCurrentAccessToken();
        if (accessToken != null) {
            //Handle Returning User
            AccountKit.getCurrentAccount(new AccountKitCallback<Account>() {
                @Override
                public void onSuccess(final Account account) {
                    // Get Account Kit ID
                    String accountKitId = account.getId();
                    Log.e("Account Kit Id", accountKitId);

                    if(account.getPhoneNumber()!=null) {
                        Log.e("CountryCode", "" + account.getPhoneNumber().getCountryCode());
                        Log.e("PhoneNumber", "" + account.getPhoneNumber().getPhoneNumber());

                        // Get phone number
                        PhoneNumber phoneNumber = account.getPhoneNumber();
                        String phoneNumberString = phoneNumber.toString();
                        Log.e("NumberString", phoneNumberString);
                    }

                    if(account.getEmail()!=null)
                        Log.e("Email",account.getEmail());
                }

                @Override
                public void onError(final AccountKitError error) {
                    // Handle Error
                    Log.e(TAG,error.toString());
                }
            });
        } else {
            //Handle new or logged out user
            Log.e(TAG,"Logged Out");
        }
    }

If the result from AccountKit Activity is okay, then we will have an AccessToken and an AccountKit Account. Depending on the login type we can get the user’s email or phone, or even both. No matter which login type is being used, the result is obtained in the same way.

To check if the user is already logged in using AccountKit, you can place getCurrentAccount() inside the onCreate() method too and it will check if there exists a AccountKit AccessToken.

The third button, will log out the current user and clear any saved access token. Its code is as below:

public void logout(@Nullable View view){
        AccountKit.logOut();
        AccessToken accessToken = AccountKit.getCurrentAccessToken();
        if(accessToken!=null)
            Log.e(TAG,"Still Logged in...");
        else
            Toast.makeText(this,"Logged Out",Toast.LENGTH_SHORT).show();
    }

These are the most important methods to keep in mind while using the Facebook Acccount Kit as an alternative login method.

Conclusion

Facebook Account Kit is a really handy tool for a simpler, faster and passwordless application login or signup. It is one of the most reliable services of its kind. Hope you enjoyed the article.

If you have any questions or comments, please let me know in the comments field below.

Frequently Asked Questions (FAQs) on Authenticating Android Users Using Phone or Email