Develop Reference

Anonymous account on Firebase is not persistent (recreated every few hours)

In my android app I offer the ability for users to add content. The user signs in anonymously on Firebase and their content is linked to their anonymous UID.
Unfortunately the anonymous account on Firebase is not persistent (every few hours a user is assigned a new UID thus loosing the ability to edit their own sets).
I execute the following logic every time the MainActivity is created:
FirebaseAuth auth = FirebaseAuth.getInstance();
if(auth.getCurrentUser() == null){
Log.d("Test", "Logging in anonymously");
auth.signInAnonymously().addOnCompleteListener(new OnCompleteListener<AuthResult>() {
#Override
public void onComplete(#NonNull Task<AuthResult> task) {
if(task.isSuccessful()){
Log.d("Test", "Anonymous Login success");
}else{
Log.d("Test", "Anonymous Login failed");
Toast.makeText(MainActivity.this, "Error while creating anonymous account", Toast.LENGTH_LONG).show();
}
}
});
}else{
Log.d("Test", "Already Logged-In");
}
How can I achieve that the anonymous accounts is permanent per device installation?

Firebase email verification WITHOUT creating and account

I'm creating an Android application that will deliver notifications.
Users can opt-in with a phone number or an email account.
I just need to verify the email the user entered, I don't want to create a Firebase account
Firebase has a FirebaseUser#sendEmailVerification() but that will require to create an account.
In other words, I just want the email verification to be the same as the Phone verification, where Firebase will just send you a code or verification link.
Is there a way to leverage Firebase email verification without creating an account?

For anyone trying to accomplish the same, here's how I was able to do it.
Go to Fibrebase console and enable Email/Password and Anonymous sign-in methods on the Authentication screen
Firebase Authentication screen
Then in you code, create an Anonymous user (this is what does the trick, because now you have a valid user to verify against), change the email, and then send a verification. After that, reload the Firebase user and check isEmailVerified()
mAuth = FirebaseAuth.getInstance();
mAuth.signInAnonymously()
.addOnCompleteListener(this, new OnCompleteListener<AuthResult>() {
#Override
public void onComplete(#NonNull Task<AuthResult> task) {
if (task.isSuccessful()) {
Log.d(TAG, "signInAnonymously:success");
if (mAuth.getCurrentUser().isEmailVerified() == false) {
mAuth.getCurrentUser().updateEmail("<MAIL YOU WANTO TO VERIFY HERE>");
mAuth.getCurrentUser().sendEmailVerification();
Log.e(TAG, "mail sent.....................................");
}
//updateUI(user);
} else {
// If sign in fails, display a message to the user.
Log.w(TAG, "signInAnonymously:failure", task.getException());
Toast.makeText(getApplicationContext(), "Authentication failed.",
Toast.LENGTH_SHORT).show();
}
}
});
Here's the reloading part:
mAuth.getCurrentUser().reload()
.addOnSuccessListener(new OnSuccessListener<Void>() {
#Override
public void onSuccess(Void aVoid) {
Log.e(TAG,( mAuth.getCurrentUser().isEmailVerified() ? "VERIFIED" : "Not verified"));
}
});

Both phone number verification and email verification are tied to a Firebase Authentication account. There is no way to use them with such an account, since the result of a verification is that a the relevant property (email_verified or phone_number) in the user account gets updated.

How to handle FirebaseAuthUserCollisionException

I started getting a FirebaseAuthUserCollisionException exception when I try to sign in with Facebook in my Android application.
com.google.firebase.auth.FirebaseAuthUserCollisionException: An
account already exists with the same email address but different
sign-in credentials. Sign in using a provider associated with this
email address.
I am using Firebase to handle the registration and Facebook to deliver a "one-click" login method, using a com.facebook.login.widget.LoginButton view as a trigger.
These sign-in method was already working. I was able to register a account with Facebook, and use the same method to log-in this account. But now have start to throwing this exception.
Here is the code where I register a account from Facebook and proceed with login:
private void handleFacebookAccessToken(AccessToken token) {
final ProgressDialog dialog = new ProgressDialog(this);
dialog.show(getString(R.string.dialog_wait));
firebaseAuth.signInWithCredential(FacebookAuthProvider.getCredential(token.getToken()))
.addOnCompleteListener(this, new OnCompleteListener<AuthResult>() {
#SuppressWarnings("ThrowableResultOfMethodCallIgnored")
#Override
public void onComplete(#NonNull Task<AuthResult> task) {
if (task.isSuccessful()) {
dialog.close();
registerNewUserFromSocialLogin(firebaseAuth.getCurrentUser());
} else {
if(task.getException() instanceof FirebaseAuthUserCollisionException) {
//TODO: handle sign-in with different credentials
} else {
dialog.close();
LoginManager.getInstance().logOut();
Toast.makeText(LoginActivity.this,
R.string.error_login,
Toast.LENGTH_SHORT).show();
}
}
}
});
}
And my Gradle file with current use library:
compile 'com.google.firebase:firebase-auth:10.2.1'
compile 'com.facebook.android:facebook-android-sdk:[4,5)'
So my problem is: I don't know how to handle FirebaseAuthUserCollisionException exception.
None of the solutions in StackOverflow or Firebase Documentation help me. I am looking for a solution that is able to login the user although the duplicated credential, to stil deliver the "one-click" login method.

You will get that error when the user had previously signed in with the same email using a different provider. For example, the user signs in with email user#gmail.com using Google. The user then tries to sign in with the same email but using Facebook. The Firebase Auth backend will return that error (account exists with different credential). In that case, you should use the fetchProvidersForEmail to look up the existing providers associated with email user#gmail.com, in this case google.com. You signInWithCredential to the existing google account to prove ownership of that account, and then linkWithCredential the Facebook credential the user originally was trying to sign in with. This merges both accounts so in the future the user can sign in with either.
This happens when you use the single accounts per email. If you want to allow different accounts per email, you can switch to multiple accounts per email in the Firebase console.
Here is an example:
mAuth.signInWithCredential(authCredential)
.addOnCompleteListener(this, new OnCompleteListener<AuthResult>() {
#Override
public void onComplete(#NonNull Task<AuthResult> task) {
// Account exists with different credential. Assume the developer wants to
// continue and link new credential to existing account.
if (!task.isSuccessful() &&
task.getException() instanceof FirebaseAuthUserCollisionException) {
FirebaseAuthUserCollisionException exception =
(FirebaseAuthUserCollisionException)task.getException();
if (exception.getErrorCode() ==
ERROR_ACCOUNT_EXISTS_WITH_DIFFERENT_CREDENTIAL) {
// Lookup existing account’s provider ID.
mAuth.fetchProvidersForEmail(existingAcctEmail)
.addOnCompleteListener(new OnCompleteListener<ProviderQueryResult> {
#Override
public void onComplete(#NonNull Task<ProviderQueryResult> task) {
if (task.isSuccessful()) {
if (task.getResult().getProviders().contains(
EmailAuthProvider.PROVIDER_ID)) {
// Password account already exists with the same email.
// Ask user to provide password associated with that account.
...
// Sign in with email and the provided password.
// If this was a Google account, call signInWithCredential instead.
mAuth.signInWithEmailAndPassword(existingAcctEmail, password)
addOnCompleteListener(new OnCompleteListener<AuthResult> {
#Override
public void onComplete(#NonNull Task<AuthResult> task) {
if (task.isSuccessful()) {
// Link initial credential to existing account.
mAuth.getCurrentUser().linkWithCredential(authCredential);
}
}
});
}
}
}
});
}
}
});

There is no need for this, you can just allow multiple accounts merge under firebaase->authentication-> sign in method -> Advanced - > change (multiple accounts per email address.
Firebase will merge the same email address but will give you different user UID.
See sample below.
AuthCredential authCredential = FacebookAuthProvider.getCredential(token.getToken());
mAuth.signInWithCredential(authCredential)
.addOnCompleteListener(this, 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();
LoginFacebookGoogleActivity.this.updateUI(user);
} else {
// If sign in fails, display a message to the user.
Log.w(TAG, "signInWithCredential:failure", task.getException());
if(task.getException() instanceof FirebaseAuthUserCollisionException){
FirebaseAuthUserCollisionException exception = (FirebaseAuthUserCollisionException) task.getException();
//log this bundle into the analytics to analyze which details you want to collect
}
Toast.makeText(LoginFacebookGoogleActivity.this, "Authentication failed " + task.getException(), Toast.LENGTH_SHORT).show();
LoginFacebookGoogleActivity.this.updateUI(null);
}
});

Firebase: One account per email is enabled still, firebase creating multiple accounts with same email

In my project at first by default 'one account per email' was enabled.
AuthCredential credential = FacebookAuthProvider.getCredential(token.getToken());
mAuth.signInWithCredential(credential)
.addOnCompleteListener(this, new OnCompleteListener<AuthResult>() {
#Override
public void onComplete(#NonNull Task<AuthResult> 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();
Toast.makeText(LoginActivity.this, user.getDisplayName(), Toast.LENGTH_SHORT).show();
updateUI();
} else {
// If sign in fails, display a message to the user.
Log.w(TAG, "signInWithCredential:failure", task.getException());
Toast.makeText(LoginActivity.this, "Authentication failed.",
Toast.LENGTH_SHORT).show();
}
}
});
I was getting authentication failed in toast message here.
Then I tried I enabling 'Multiple accounts per email', just to try that feature.
After that, I reverted back by again enabling 'one account per email'
But now firebase is creating multiple accounts even when I've disabled it in settings.
I want it to again return auth failed if an account exists.

How to send verification email with Firebase?

I am signing up my users using Firebase's email and password method. like this:
mAuth.createUserWithEmailAndPassword(email, password)
.addOnCompleteListener(this, new OnCompleteListener<AuthResult>() {
#Override
public void onComplete(#NonNull Task<AuthResult> task) {
if (task.isSuccessful()) {
FirebaseUser signed = task.getResult().getUser();
writeNewUser(signed.getUid());
new android.os.Handler().postDelayed(
new Runnable() {
public void run() {
updateUser(b);
}
}, 3000);
} else {
new android.os.Handler().postDelayed(
new Runnable() {
public void run() {
onSignupFailed();
}
}, 3000);
}
}
});
After the user's email has been successfully registered, I would like Firebase to send a verification email. I know this is possible using Firebase's sendEmailVerification. In addition to sending this email, I want the user's account to be disabled until they verify the email. This would also require using Firebase's isEmailVerified feature. However, I have been unsuccessful in getting Firebase to send the verification email, I have not been able to figure out to get it to disable and enable the account sending the verification email and after it has been verified.

This question is about how to use Firebase to send the verification email. The OP is unable to figure out how to disable and enable the account sending the verification email and after it has been verified.
Also, this is not properly documented in the firebase documentation. So I am writing a step by step procedure that someone may follow if he/she is facing the problem.
1) User can use createUserWithEmailAndPassword method.
Example:
mAuth.createUserWithEmailAndPassword(email, password)
.addOnCompleteListener(this, new OnCompleteListener<AuthResult>() {
#Override
public void onComplete(#NonNull Task<AuthResult> task) {
Log.d("TAG", "createUserWithEmail:onComplete:" + task.isSuccessful());
// If sign in fails, display a message to the user. If sign in succeeds
// the auth state listener will be notified and logic to handle the
// signed in user can be handled in the listener.
if (!task.isSuccessful()) {
// Show the message task.getException()
}
else
{
// successfully account created
// now the AuthStateListener runs the onAuthStateChanged callback
}
// ...
}
});
If the new account was created, the user is also signed in, and the AuthStateListener runs the onAuthStateChanged callback. In the callback, you can manage the work of sending the verification email to the user.
Example:
onCreate(...//
mAuthListener = new FirebaseAuth.AuthStateListener() {
#Override
public void onAuthStateChanged(#NonNull FirebaseAuth firebaseAuth) {
FirebaseUser user = firebaseAuth.getCurrentUser();
if (user != null) {
// User is signed in
// NOTE: this Activity should get onpen only when the user is not signed in, otherwise
// the user will receive another verification email.
sendVerificationEmail();
} else {
// User is signed out
}
// ...
}
};
Now the send verification email can be written like:
private void sendVerificationEmail()
{
FirebaseUser user = FirebaseAuth.getInstance().getCurrentUser();
user.sendEmailVerification()
.addOnCompleteListener(new OnCompleteListener<Void>() {
#Override
public void onComplete(#NonNull Task<Void> task) {
if (task.isSuccessful()) {
// email sent
// after email is sent just logout the user and finish this activity
FirebaseAuth.getInstance().signOut();
startActivity(new Intent(SignupActivity.this, LoginActivity.class));
finish();
}
else
{
// email not sent, so display message and restart the activity or do whatever you wish to do
//restart this activity
overridePendingTransition(0, 0);
finish();
overridePendingTransition(0, 0);
startActivity(getIntent());
}
}
});
}
Now coming to LoginActivity:
Here if the user is successfully logged in then we can simply call a method where you are writing logic for checking if the email is verified or not.
Example:
mAuth.signInWithEmailAndPassword(email, password)
.addOnCompleteListener(this, new OnCompleteListener<AuthResult>() {
#Override
public void onComplete(#NonNull Task<AuthResult> task) {
//Log.d("TAG", "signInWithEmail:onComplete:" + task.isSuccessful());
// If sign in fails, display a message to the user. If sign in succeeds
// the auth state listener will be notified and logic to handle the
// signed in user can be handled in the listener.
if (!task.isSuccessful()) {
//Log.w("TAG", "signInWithEmail:failed", task.getException());
} else {
checkIfEmailVerified();
}
// ...
}
});
Now consider the checkIfEmailVerified method:
private void checkIfEmailVerified()
{
FirebaseUser user = FirebaseAuth.getInstance().getCurrentUser();
if (user.isEmailVerified())
{
// user is verified, so you can finish this activity or send user to activity which you want.
finish();
Toast.makeText(LoginActivity.this, "Successfully logged in", Toast.LENGTH_SHORT).show();
}
else
{
// email is not verified, so just prompt the message to the user and restart this activity.
// NOTE: don't forget to log out the user.
FirebaseAuth.getInstance().signOut();
//restart this activity
}
}
So here I m checking if the email is verified or not. If not, then log out the user.
So this was my approach to keeping track of things properly.

send verification to user's Email
FirebaseUser user = FirebaseAuth.getInstance().getCurrentUser();
user.sendEmailVerification();
check if user is verified
FirebaseUser user = FirebaseAuth.getInstance().getCurrentUser();
boolean emailVerified = user.isEmailVerified();

Use FirebaseAuth.getInstance().getCurrentUser().sendEmailVerification() and FirebaseAuth.getInstance().getCurrentUser().isEmailVerified()
There is no way to disable the account via the Firebase SDK. The thing you can do is use the GetTokenResult containing the Firebase Auth ID Token and validate it against your custom backend or set a flag to Firebase database corresponding to that user. Personally I'd go with the flag in the Firebase database

For sending email link with Firebase first you need to grab FirebaseAuth instance
using the instance we create user on Firebase through:
firebaseauth.createUserWithEmailAndPassword(email,pass);
When method return success we send verification link to user using Firebase user instance as follows:
final FirebaseUser user = mAuth.getCurrentUser();
user.sendEmailVerification()
See this link: https://technicalguidee.000webhostapp.com/2018/10/email-verification-through-link-using-firebase-authentication-product-android.

mAuth.createUserWithEmailAndPassword(email,password).addOnCompleteListener(new OnCompleteListener<AuthResult>() {
#Override
public void onComplete(#NonNull Task<AuthResult> task) {
if(task.isSuccessful()){
mAuth.getCurrentUser().sendEmailVerification().addOnCompleteListener(new OnCompleteListener<Void>() {
#Override
public void onComplete(#NonNull Task<Void> task) {
if (task.isSuccessful()) {
Toast.makeText(this, "please check email for verification.", Toast.LENGTH_SHORT).show();
loadingBar.dismiss();
}else{
Toast.makeText(this, task.getException().getMessage() , Toast.LENGTH_SHORT).show();
}
}
});

For Kotlin
val user: FirebaseUser? = firebaseAuth.currentUser
user?.sendEmailVerification()