Flutter: LateInitializationError: Field '_name' has not been initialized - flutter

Question

I recently use to using firebase core made some changes to my code that I don't quite understand. I'm new to programming flutter. Any way, I've tried reading this similar thread here about it but I still don't quite understand it. Can someone please provide an example code of what's needed to solve for the error below?
Firebase.dart
import 'package:firebase_auth/firebase_auth.dart';
import 'package:cloud_firestore/cloud_firestore.dart';
import 'package:flutter/material.dart';
import 'package:mybankapp/routscreens/routwidget.dart';
class FirebaseAuthMethods {
final _firestore = FirebaseFirestore.instance;
final _firebaseAuth = FirebaseAuth.instance;
//Email Registration
Future<void> signUpWithEmail({
required String name,
required String email,
required String password,
}) async {
await _firebaseAuth.createUserWithEmailAndPassword(
email: email,
password: password,
);
await sendEmailVerification();
await _firestore
.collection('users')
.doc(FirebaseAuth.instance.currentUser!.uid)
.set({
'Name': name,
'email': email,
});
}
//Email Login
Future<void> loginWithEmail({
required String email,
required String password,
}) async {
try{
await _firebaseAuth.signInWithEmailAndPassword(
email: email,
password: password,
);
if (!_firebaseAuth.currentUser!.emailVerified){
await sendEmailVerification();
//show mail not verified and mail verification is sent again.
}else {
NavigationBarBottom();
//Show Home Page
}
} on FirebaseAuthException catch (e){
e.message!;
//show snackbar for error mwssage
}
}
//Email Verification
Future<void> sendEmailVerification() async{
try{
_firebaseAuth.currentUser!.sendEmailVerification();
//Snackbar for Verification Mail
} on FirebaseAuthException catch(e){
//Snackbar for error email msg
}
}
}
SignUpPage.dart
import 'package:flutter/gestures.dart';
import 'package:flutter/material.dart';
import 'package:get/get.dart';
import 'package:mybankapp/authscreens/loginscreen.dart';
import 'package:mybankapp/colors/colors.dart';
import 'package:mybankapp/routscreens/routwidget.dart';
import 'package:mybankapp/textfontfamily/textfontfamily.dart';
import 'package:mybankapp/welcomescreen/welcomescreen.dart';
import 'package:firebase_auth/firebase_auth.dart';
import 'package:cloud_firestore/cloud_firestore.dart';
import 'package:mybankapp/firebase_services/firebase_auth';
class SignUpScreen extends StatefulWidget {
#override
_SignUpScreenState createState() => _SignUpScreenState();
}
class _SignUpScreenState extends State<SignUpScreen> {
final _formKey = GlobalKey<FormState>();
final FirebaseAuthMethods firebaseAuthMethods = FirebaseAuthMethods();
late String _name;
late String _emailAddress = '';
late String _password;
late String _confirmPassword;
final bool _isLoading = false;
void signUpUser() async {
try {
firebaseAuthMethods.signUpWithEmail(
name: _name,
email: _emailAddress,
password: _password,
);
} on FirebaseAuthException catch (e) {
print(e.message!);
//Snackbar for error mail
}
//NavigationBarBottom();
}
Text text(String text) {
return Text(
text,
style: TextStyle(
fontSize: 10,
fontFamily: TextFontFamily.helveticaNeueCyrRoman,
color: ColorResources.white,
),
);
}
TextFormField textFormField(String hint, String? Function(String?) validator,
void Function(String?) onSaved,
{bool obscureText = false}) {
return TextFormField(
style: TextStyle(
fontFamily: TextFontFamily.helveticaNeueCyrRoman,
fontSize: 13,
color: ColorResources.grey2,
),
obscureText: obscureText,
cursorColor: ColorResources.blue1,
decoration: InputDecoration(
filled: true,
fillColor: ColorResources.grey1.withOpacity(0.05),
hintText: hint,
isDense: true,
hintStyle: TextStyle(
fontFamily: TextFontFamily.helveticaNeueCyrRoman,
fontSize: 13,
color: ColorResources.grey2,
),
enabledBorder: OutlineInputBorder(
borderRadius: BorderRadius.circular(5),
borderSide: BorderSide(
width: 1,
color: ColorResources.blue1.withOpacity(0.6),
),
),
border: OutlineInputBorder(
borderRadius: BorderRadius.circular(5),
borderSide: BorderSide(
width: 1,
color: ColorResources.blue1.withOpacity(0.6),
),
),
errorBorder: OutlineInputBorder(
borderRadius: BorderRadius.circular(5),
borderSide: BorderSide(
width: 1,
color: ColorResources.blue1.withOpacity(0.6),
),
),
focusedBorder: OutlineInputBorder(
borderRadius: BorderRadius.circular(5),
borderSide: BorderSide(
width: 1,
color: ColorResources.blue1.withOpacity(0.6),
),
),
),
validator: validator,
onSaved: onSaved,
);
}
// emailAddress validation
// ignore: valid_regexps
final _emailAddressRegExp =
RegExp(r'^.+#[a-zA-Z]+\.{1}[a-zA-Z]+(\.{0,1}[a-zA-Z]+)$');
#override
Widget build(BuildContext context) {
return Scaffold(
backgroundColor: ColorResources.backGroundColor,
body: SingleChildScrollView(
child: Padding(
padding: const EdgeInsets.only(top: 50, left: 15, right: 15),
child: Column(
crossAxisAlignment: CrossAxisAlignment.start,
children: [
InkWell(
onTap: () {
Get.off(WelcomeScreen());
},
child: Icon(
Icons.close,
color: ColorResources.white,
),
),
SizedBox(height: 70),
Text(
"Create Account",
style: TextStyle(
fontFamily: TextFontFamily.helveticNeueCyrBold,
fontSize: 35,
color: ColorResources.red),
),
SizedBox(height: 7),
Text(
"Open a Noble Bank account with a few details.",
style: TextStyle(
fontFamily: TextFontFamily.helveticaNeueCyrRoman,
fontSize: 15,
color: ColorResources.white1),
),
SizedBox(height: 40),
Form(
key: _formKey,
child: Column(
crossAxisAlignment: CrossAxisAlignment.start,
children: [
text("Full name"),
SizedBox(height: 10),
textFormField("", (value) {
if (value!.isEmpty) {
return "Please enter your name";
}
return null;
}, (value) {
_name = value!;
}),
SizedBox(height: 20),
text("Email Address"),
SizedBox(height: 10),
textFormField("", (value) {
if (!_emailAddressRegExp.hasMatch(value!)) {
return "Please enter your email address";
}
return null;
}, (value) {
_emailAddress = value!;
}),
SizedBox(height: 20),
text("Password"),
SizedBox(height: 10),
textFormField("", (value) {
if (value!.isEmpty) {
return "Please enter your password";
} else if (value.length < 8) {
return "Password must be at least 8 characters long";
}
return null;
}, (value) {
_password = value!;
}, obscureText: true),
SizedBox(height: 20),
text("Repeat password"),
SizedBox(height: 10),
textFormField("", (value) {
if (value!.isEmpty) {
return "Please enter your password";
} else if (value != _password) {
return "Password doesn't match";
}
return null;
}, (value) {
_confirmPassword = value!;
}, obscureText: true),
],
),
),
SizedBox(height: Get.height >= 876 ? 150 : 50),
_isLoading
? CircularProgressIndicator()
: SizedBox(
width: double.infinity,
child: InkWell(
onTap: signUpUser,
child: Container(
height: 50,
width: Get.width,
decoration: BoxDecoration(
color: ColorResources.red,
borderRadius: BorderRadius.circular(10),
),
child: Center(
child: Text(
"CREATE YOUR FREE ACCOUNT",
style: TextStyle(
fontFamily:
TextFontFamily.helveticaNeueCyrRoman,
fontWeight: FontWeight.w700,
fontSize: 13.5,
color: ColorResources.white),
),
),
),
),
),
SizedBox(height: 20),
Center(
child: RichText(
text: TextSpan(
text: "Do you already have a Noble Bank account?",
style: TextStyle(
fontSize: 13.5,
fontWeight: FontWeight.w300,
fontFamily: TextFontFamily.helveticaNeueCyrRoman,
color: ColorResources.white2,
),
children: <TextSpan>[
TextSpan(
recognizer: TapGestureRecognizer()
..onTap = () => Get.to(LogInScreen()),
text: " Sign in here",
style: TextStyle(
fontSize: 14,
fontFamily: TextFontFamily.helveticaNeueCyrRoman,
fontWeight: FontWeight.w300,
color: ColorResources.red,
),
),
],
),
),
),
],
),
),
),
);
}
}

Answer 1

If you cannot guarantee that _name (and the other fields) are set to a valid value before you call signUpUser(), you should not make the late.
Instead, make them nullable as in
String? _name;
And check for non-null values bevor using the data to create the user account.