How to save login Credential with Firebase - firebase

Question

I'm having an interface where we should log in by providing the email and password.
Below is my login page.
the interface is designed using dart with flutter.
What I want is to save the email and password when the user (checks the remember me box and then)login to the account.
When the user comes back again to the same page, the page should automatically fill the username and password for the user.
For now, it saves the credentials in the firebase authentication.
Below is my code for Remember me checkbox and login.
Widget _RememberMeCheckbox() {
return Container(
height: 20.0,
child: Row(
children: <Widget>[
Theme(
data: ThemeData(unselectedWidgetColor: Colors.white),
child: Checkbox(
value: _rememberMe,
checkColor: Colors.green,
activeColor: Colors.white,
onChanged: (value) {
setState(() {
_rememberMe = value;
});
},
),
),
Text(
'Remember me',
style: kLabelStyle,
),
],
),
);
}
Widget _LoginBtn() {
return Container(
padding: EdgeInsets.symmetric(vertical: 25.0),
width: double.infinity,
child: Form(
child: RaisedButton(
elevation: 5.0,
onPressed: () async {
final form = formKey.currentState;
form.save();
if (form.validate()) {
try {
FirebaseUser result =
await Provider.of<AuthService>(context, listen: false)
.loginUser(email: _email, password: _password);
print(result);
Navigator.of(context).pushNamed('/home');
} on AuthException catch (ex) {
return _showErrorDialog(context, ex.message);
} on Exception catch (ex) {
return _showErrorDialog(context, ex.toString());
}
}
},
padding: EdgeInsets.all(15.0),
shape: RoundedRectangleBorder(
borderRadius: BorderRadius.circular(30.0),
),
color: Colors.white,
child: Text(
'LOGIN',
style: TextStyle(
color: Color(0xFF527DAA),
letterSpacing: 1.5,
fontSize: 18.0,
fontWeight: FontWeight.bold,
fontFamily: 'OpenSans',
),
),
),
),
);
}
I need to do this using firebase can anyone help me?
String_email="";
String_password="";
Widget _EmailTextField() {
return Column(
crossAxisAlignment: CrossAxisAlignment.start,
children: <Widget>[
Text(
'Email',
style: kLabelStyle,
),
SizedBox(height: 10.0),
Container(
alignment: Alignment.centerLeft,
decoration: kBoxDecorationStyle,
height: 60.0,
child: TextFormField(
keyboardType: TextInputType.text,
autovalidate: false,
style: TextStyle(
color: Colors.white,
fontFamily: 'OpenSans',
),
decoration: InputDecoration(
border: InputBorder.none,
contentPadding: EdgeInsets.only(top: 14.0),
prefixIcon: Icon(
Icons.email,
color: Colors.white,
),
hintText: 'Enter your Email Address',
hintStyle: kHintTextStyle,
),
validator: (String value) {
if (value.isEmpty) {
return 'Email is Required.';
}
Pattern pattern =
r'^(([^<>()[\]\\.,;:\s#\"]+(\.[^<>()[\]\\.,;:\s#\"]+)*)|(\".+\"))#((\[[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}\])|(([a-zA-Z\-0-9]+\.)+[a-zA-Z]{2,}))$';
RegExp regex = new RegExp(pattern);
if (!regex.hasMatch(value)) {
return 'Enter valid Email Address';
}
return null;
},
onSaved: (String value) {
return _email = value;
},
),
),
],
);
}
Widget _PasswordTextField() {
return Column(
crossAxisAlignment: CrossAxisAlignment.start,
children: <Widget>[
Text(
'Password',
style: kLabelStyle,
),
SizedBox(height: 10.0),
Container(
alignment: Alignment.centerLeft,
decoration: kBoxDecorationStyle,
height: 60.0,
child: TextFormField(
autovalidate: false,
style: TextStyle(
color: Colors.white,
fontFamily: 'OpenSans',
),
decoration: InputDecoration(
border: InputBorder.none,
contentPadding: EdgeInsets.only(top: 14.0),
prefixIcon: Icon(
Icons.lock,
color: Colors.white,
),
suffixIcon: IconButton(
icon: Icon(
_passwordVisible ? Icons.visibility : Icons.visibility_off,
color: Colors.white,
),
onPressed: _passwordVisibility,
),
hintText: 'Enter your Password',
hintStyle: kHintTextStyle,
),
obscureText: !_passwordVisible,
validator: (String value) {
if (value.isEmpty) {
return 'Password is Required.';
}
if (value.length < 6) {
return 'Password too short.';
}
return null;
},
onSaved: (String value) {
return _password = value;
},
),
),
],
);
}

Answer 1

There are a few options:
Read and write files: https://flutter.io/reading-writing-files/
SQLite via a Flutter plugin: https://github.com/tekartik/sqflite
SQLCipher via a Flutter plugin: https://github.com/drydart/flutter_sqlcipher
SharedPreferences via a Flutter plugin: https://github.com/flutter/plugins/tree/master/packages/shared_preferences