How to do Phone Authentication in Flutter using Firebase?

Question

I have searched many websites and I didn\'t find a way to implement phone authentication in Flutter using Firebase. Can anyone tell me how to this?

Answer 1

I have implemented the phone auth singnIn with firebase in flutter its quite easy just import the firebase_auth library and validate the phone number is in proper format i.e it has a "+" sign in the beginning followed by country code then the phone number then the code goes like this

if (phoneExp.hasMatch(phon))
   {
      final PhoneVerificationCompleted verificationCompleted=(FirebaseUser user){
        setState(() {
                      _message=Future.value("auto sign in succedded $user");
                      debugPrint("Sign up succedded");
                      _pref.setString("phonkey",user.phoneNumber.toString());
                      MyNavigator.goToDetail(context);
//called when the otp is variefied automatically
                    });
      };
  final PhoneVerificationFailed verificationFailed=(AuthException authException){
    setState(() {
                  _message=Future.value("verification failed code: ${authException.code}. Message: ${authException.message}");
                });
  };

  final PhoneCodeSent codeSent=(String verificationId,[int forceResendingToken]) async {
    this.verificationId=verificationId;


  };

  final PhoneCodeAutoRetrievalTimeout codeAutoRetrievalTimeout = (String verificationId){
    this.verificationId=verificationId;

  };

  await _auth.verifyPhoneNumber(
    phoneNumber: phon,
    timeout: Duration(seconds: 60),
    verificationCompleted: verificationCompleted,
    verificationFailed: verificationFailed,
    codeSent: codeSent,
    codeAutoRetrievalTimeout: codeAutoRetrievalTimeout
    );



}

and if the phone wasn't able to detect the otp sent automatically, get the otp in a string and implement this function

void _signInWithOtp() async{
  final FirebaseUser user = await _auth.signInWithPhoneNumber(
  verificationId: verificationId,
  smsCode: _otpController.text,
);