Ndtyjky

I am little bit confused about the right flow of the phone authentication.
I have noticed there is couple of scenarios that I cannot reproduce due to reason I can not completely delete my user from Firebase and reproduce all scenarios. The possible scenarios are:

1. User never logged in to firebase


2. User previously logged in and signed out, and on sign in receives SMS


3. User previously logged in and signed out, and on sign in not receiving SMS

What happens for me is scenario 2. My log for this is:

D/DTAG: Asking verification for: +972052*****77

D/DTAG: 2. Sending for verification and waiting response to callbacks

D/DTAG: 3.b. Sending code

D/DTAG: 3.a. Verification complete, signing in

D/DTAG: signInWithCredential:success

Question 1: So now the SMS is irrelevant, right? I can login without checking the SMS code?

Question 2: At scenario 1, does callback "onVerificationCompleted" not called at all?

Question 3: At scenario 3, the callback "onCodeSent" not called at all?

Question 4: How can I retrieve the SMS code at "onCodeSent"?. I know I can at "onVerificationCompleted" to use phoneAuthCredential.getSmsCode(), but there are scenarios when it not called.

My code:

public class MyVerifyPhoneActivity extends AppCompatActivity {



    private static final String TAG = "DTAG";

    EditText editTextCode;

    Button buttonLogin;

    String mVerificationId;



    @Override

    protected void onCreate(Bundle savedInstanceState) {

        super.onCreate(savedInstanceState);

        setContentView(R.layout.activity_my_verify_phone);



        editTextCode = findViewById(R.id.editTextCode);

        buttonLogin = findViewById(R.id.myButtonSignIn);



        String phonenumber = getIntent().getStringExtra("phonenumber");

        Log.d(TAG,"Asking verification for: "+phonenumber);

        sendVerificationCode(phonenumber);





        buttonLogin.setOnClickListener(new View.OnClickListener() {

            @Override

            public void onClick(View v) {



                String code = editTextCode.getText().toString().trim();

                Log.d(TAG,"Button login clicked");



                if (code.isEmpty() || code.length() < 6) {



                    editTextCode.setError("Enter code...");

                    editTextCode.requestFocus();

                    return;

                }



                verifyCode(code);

            }

        });





    }



    private void sendVerificationCode(String number) {



        Log.d(TAG,"2. Sending for verification and waiting response to callbacks");

        PhoneAuthProvider.getInstance().verifyPhoneNumber(

                number,

                60,

                TimeUnit.SECONDS,

                TaskExecutors.MAIN_THREAD,

                mCallBack

        );



    }



    private PhoneAuthProvider.OnVerificationStateChangedCallbacks mCallBack = new PhoneAuthProvider.OnVerificationStateChangedCallbacks() {



        @Override

        public void onVerificationCompleted(PhoneAuthCredential phoneAuthCredential) {



            Log.d(TAG,"3.a. Verification complete, signing in");

            signInWithPhoneAuthCredential(phoneAuthCredential);

        }



        @Override

        public void onCodeSent(String verificationId, PhoneAuthProvider.ForceResendingToken forceResendingToken) {

            super.onCodeSent(verificationId, forceResendingToken);



            mVerificationId = verificationId;

            Log.d(TAG,"3.b. Sending code");



        }



        @Override

        public void onVerificationFailed(FirebaseException e) {

            Log.w(TAG, "onVerificationFailed", e);

            Log.d(TAG,"3.c. Failed");



            if (e instanceof FirebaseAuthInvalidCredentialsException) {

                // Invalid request

                // ...

            } else if (e instanceof FirebaseTooManyRequestsException) {

                // The SMS quota for the project has been exceeded

                // ...

            }

        }

    };





    private void verifyCode(String code)

    {

        Log.d(TAG,"verifying Code");

        PhoneAuthCredential credential = PhoneAuthProvider.getCredential(mVerificationId, code);

         signInWithPhoneAuthCredential(credential);

    }







    private void signInWithPhoneAuthCredential(PhoneAuthCredential credential) {



        FirebaseAuth.getInstance().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("DTAG", "signInWithCredential:success");



                    FirebaseUser user = task.getResult().getUser();



                } else {

                    // Sign in failed, display a message and update the UI

                    Log.w("DTAG", "signInWithCredential:failure", task.getException());

                    if (task.getException() instanceof FirebaseAuthInvalidCredentialsException) {

                        // The verification code entered was invalid

                    }

                }

            }

        });

    }





}

I cannot reproduce due to reason I can not completely delete my user from Firebase

-> Yes you can. have a look at image.

Answer of Question 1:
-> It is not. SMS is obviously relevant. without SMS, phone-authentication will not work.

Answer of Question 2:
-> onVerificationCompleted will be called every-time.

Answer of Question 3:
-> Yes. onCodeSent is not being called every-time.

Answer of Question 4:
-> You do not need OTP in onCodeSent method. We can get verificationId and PhoneAuthProvider.ForceResendingToken in onCodeSent. we need to save verificationId in a variable. and use it while authentication user entered OTP.

PhoneAuthCredential credential = PhoneAuthProvider.getCredential(mVerificationId, YouEditTextValueString);

My opinion:
I had also these questions in my mind when I worked first time on it. I experienced that if we use same device with same phone-number, SMS is not coming and I guess Firebase or google-play-service handle it.

Somehow right-now I am receiving SMS every time for the same device and phone-number.

but we don't need to care about it.