Android, Kotlin using firebase

Question

I hope you are doing great.

I have the following code, that I am using to create an account using firebase. I have used the statements to validate the credentials. I don´t know what to right more to validade the post of this question, so sorry for having to read this.

class SignUp : AppCompatActivity() {

    private lateinit var binding: ActivitySignUpBinding

    private lateinit var actionBar: ActionBar

    private lateinit var progressDialog: ProgressDialog

    private lateinit var firebaseAuth: FirebaseAuth

    private var email=""
    private var password=""
    private var passwordrepeat=""

    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        binding = ActivitySignUpBinding.inflate(layoutInflater)
        setContentView(binding.root)

        actionBar = supportActionBar!!
        actionBar.title="Sign Up"
        actionBar.setDisplayHomeAsUpEnabled(true)
        actionBar.setDisplayShowHomeEnabled(true)

        progressDialog = ProgressDialog(this)
        progressDialog.setTitle("Please Wait")
        progressDialog.setMessage("Creating account")
        progressDialog.setCanceledOnTouchOutside(false)

        firebaseAuth = FirebaseAuth.getInstance()

        binding.buttonSignUp.setOnClickListener{
            validateData()
        }

    }
    val EMAIL_ADDRESS_PATTERN = Pattern.compile(
        "[a-zA-Z0-9\\+\\.\\_\\%\\-\\+]{1,256}" +
                "\\@" +
                "test" +
                "(" +
                "\\." +
                "com" +
                ")+"
    )

    fun isValidString(str: String): Boolean{
        return EMAIL_ADDRESS_PATTERN.matcher(str).matches()
    }
    private fun validateData() {
        email = binding.emailText.text.toString().trim()
        password = binding.passwordText.text.toString().trim()
        passwordrepeat = binding.passwordText2.text.toString().trim()

          if (!isValidString(email)) {
            binding.emailTF.error = "Use ipvc email"

       // } else if(){

        }else if (TextUtils.isEmpty(password)) {
            binding.passwordTF.error = "Please enter password"
        }else if(TextUtils.isEmpty(passwordrepeat)){
            binding.passwordTF2.error="Please repeat password"
        }else if(password != passwordrepeat) {
            binding.passwordTF2.error="Passwords don´t match"
        }else if (password.length < 6){
            binding.passwordTF.error = "Password must have atleast 6 caracters"
        }else{
            firebaseSignUp()
        }
    }

    private fun firebaseSignUp() {
        progressDialog.show()

        firebaseAuth.createUserWithEmailAndPassword(email, password)
            .addOnSuccessListener {
                val firebaseUser = firebaseAuth.currentUser
                val email = firebaseUser!!.email
                Toast.makeText(this, "Account have been created with email $email", Toast.LENGTH_LONG)

                startActivity(Intent(this, Perfil::class.java))
                finish()
            }
            .addOnFailureListener{e->
                progressDialog.dismiss()
                Toast.makeText(this, "Sign Up Failded due to ${e.message}", Toast.LENGTH_LONG)
            }
    }

    override fun onSupportNavigateUp(): Boolean {
        onBackPressed() //Voltar a atrás quando o botão é pressionado
        return super.onSupportNavigateUp()
    }

How can I add a verification thats verifies if the account has already been created while creating it? The username in this case is the Email.

Answer 1

Your failure listener will be invoked with a FirebaseAuthUserCollisionException indicating the user's email is already taken.

You can read more about this and the other failure cases in the documentation.