firebase

Google Sign in Android Example using Firebase Auth. In this blog you'll learn how to allow your Android app users to sign in to your app using Firebase Auth Tool and also access their data from Firebase Dashboard. Prerequisite Creating Project at Firebase To start, Sign in / Sign Up to Firebase.com using your Google Account. Once Signed in, click on 'Add Project'. Google Sign in Android Example Create a new project and continue to dashboard. Google Sign in Android Example Once inside the dashboard, add an Android App to project and provide your app package name. (You can find this in your Android Studio project, 'AndroidManifest.xml' file.) Google Sign in Android Example Download 'google-serivces.json' file and add this to your Project as directed by Firebase. Google Sign in Android Example Inside Firebase Console Go to Firebase Console, Select your Project and inside it go 'Authentication' from the left panel inside 'Develop' section. Click on 'Set up Sign-in method'. Google Sign in Android Example See for 'Google' in Provider section. Select that option and 'Enable' it. (Don't forget to provide Email Address) Google Sign in Android Example Now switch back to your Android Studio Project! Inside Android Studio In Android Studio project make sure, you've added 'google-services.json' file. Implement following libraries in your project by adding these line of codes to your build.gradle (Modeule: app) implementation 'com.google.firebase:firebase-core:16.0.6' implementation 'com.google.firebase:firebase-auth:16.1.0' implementation 'com.google.android.gms:play-services-auth:16.0.1' Next, open 'activity_main.xml' file (or xml file where you want to put Google sign in button) Add following lines of code to add Google Sign in Button: <com.google.android.gms.common.SignInButton android:id"@+id/signInButton" android:layout_width"250dp" android:layout_height"wrap_content" android:layout_marginStart"8dp" android:layout_marginEnd"8dp" android:layout_marginBottom"48dp" app:layout_constraintBottom_toBottomOf"parent" app:layout_constraintEnd_toEndOf"parent" app:layout_constraintHorizontal_bias"0.496" app:layout_constraintStart_toStartOf"parent" /> Google Sign in Android Example To learn how use gradient background in app as shown in preview, click to read here! Now go to 'MainActivity.java' file and create SignInButton and few other objects as shown below. SignInButton signInButton; GoogleSignInClient mGoogleSignInClient; final int RC_SIGN_IN 123; String TAG "SignUp_Activity"; private FirebaseAuth mAuth; in onCreate(); add this code: signInButton findViewById(R.id.signInButton); Now we'll need GoogleSignInOption object for requesting user details! Write following lines of code in onCreate(); GoogleSignInOptions gso new GoogleSignInOptions.Builder(GoogleSignInOptions.DEFAULT_SIGN_IN) .requestIdToken(default_web_client_id) .requestEmail() .build(); mGoogleSignInClient GoogleSignIn.getClient(this, gso); Now create a signIn(); method for app to show popup, so user can select his account and approve app request to his/her account details. Code is here: private void signIn() { Intent signInIntent mGoogleSignInClient.getSignInIntent(); startActivityForResult(signInIntent, RC_SIGN_IN); } Set an on click listener for 'SignInButton' using following code in onCreate(); and call this signIn(); method signInButton.setOnClickListener(new View.OnClickListener() { @Override public void onClick(View v) { signIn(); } }); In the code above, once user clicks on button, the signIn(); method is called. Inside this method, intent is created and a result data is received. To parse this code we will create a method called firebaseAuthWithGoogle(); which will take Google Sign in Account object as parameter. private void firebaseAuthWithGoogle(GoogleSignInAccount acct) { Log.d(TAG, "firebaseAuthWithGoogle:" + acct.getId()); AuthCredential credential GoogleAuthProvider.getCredential(acct.getIdToken(), null); mAuth.signInWithCredential(credential) .addOnCompleteListener(this, new OnCompleteListener () { @Override public void onComplete(@NonNull Task task) { if (task.isSuccessful()) { // Sign in success, update UI with the signed-in user's information Log.d(TAG, "signInWithCredential:success"); FirebaseUser user mAuth.getCurrentUser(); Intent intent new Intent(MainActivity.this,HomeActivity.class); startActivity(intent); } else { // If sign in fails, display a message to the user. Log.w(TAG, "signInWithCredential:failure", task.getException()); Toast.makeText(SignUp_Activity.this, "Authentication Failed.", Toast.LENGTH_SHORT).show(); } // ... } }); } In the code above, once the sign in succeeded, the user is directed to another activity called, 'HomeActivity.class'. (Update UI as per your preference.) Now, we'll create another method named onActivityResult(); which will handle result received from Intent. This method will have 3 parameters as shown below: @Override public void onActivityResult(int requestCode, int resultCode, Intent data) { super.onActivityResult(requestCode, resultCode, data); // Result returned from launching the Intent from GoogleSignInApi.getSignInIntent(...); if (requestCode RC_SIGN_IN) { Task task GoogleSignIn.getSignedInAccountFromIntent(data); try { // Google Sign In was successful, authenticate with Firebase GoogleSignInAccount account task.getResult(ApiException.class); firebaseAuthWithGoogle(account); } catch (ApiException e) { // Google Sign In failed, update UI appropriately Log.w(TAG, "Google sign in failed", e); // ... } } } Hurray!, we're now finished implementing Google sign in button for Android. You can go ahead and test your app now. Here is a full code for you to review what we did in MainActivity.class: public class MainActivity extends AppCompatActivity { SignInButton signInButton; Button signUpBtn; GoogleSignInClient mGoogleSignInClient; final int RC_SIGN_IN 123; String TAG "SignUp_Activity"; private FirebaseAuth mAuth; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_sign_up_); signInButton findViewById(R.id.signInButton); signInButton.setOnClickListener(new View.OnClickListener() { @Override public void onClick(View v) { signIn(); } }); GoogleSignInOptions gso new GoogleSignInOptions.Builder(GoogleSignInOptions.DEFAULT_SIGN_IN) .requestIdToken(default_web_client_id) .requestEmail() .build(); mGoogleSignInClient GoogleSignIn.getClient(this, gso); } private void signIn() { Intent signInIntent mGoogleSignInClient.getSignInIntent(); startActivityForResult(signInIntent, RC_SIGN_IN); } @Override public void onActivityResult(int requestCode, int resultCode, Intent data) { super.onActivityResult(requestCode, resultCode, data); // Result returned from launching the Intent from GoogleSignInApi.getSignInIntent(...); if (requestCode RC_SIGN_IN) { Task task GoogleSignIn.getSignedInAccountFromIntent(data); try { // Google Sign In was successful, authenticate with Firebase GoogleSignInAccount account task.getResult(ApiException.class); firebaseAuthWithGoogle(account); } catch (ApiException e) { // Google Sign In failed, update UI appropriately Log.w(TAG, "Google sign in failed", e); // ... } } } private void firebaseAuthWithGoogle(GoogleSignInAccount acct) { Log.d(TAG, "firebaseAuthWithGoogle:" + acct.getId()); AuthCredential credential GoogleAuthProvider.getCredential(acct.getIdToken(), null); mAuth.signInWithCredential(credential) .addOnCompleteListener(this, new OnCompleteListener () { @Override public void onComplete(@NonNull Task task) { if (task.isSuccessful()) { // Sign in success, update UI with the signed-in user's information Log.d(TAG, "signInWithCredential:success"); Intent intent new Intent(SignUp_Activity.this,HomeActivity.class); startActivity(intent); } else { // If sign in fails, display a message to the user. Log.w(TAG, "signInWithCredential:failure", task.getException()); Toast.makeText(SignUp_Activity.this, "Authentication Failed.", Toast.LENGTH_SHORT).show(); } // ... } }); } }