Working With Seperate Files in Flutter/Dart - flutter

Question

I am newbie at Dart and OOP.I have one input.dart file for Text Form Fields and login.dart file to conduct login.My problem is I want to acces text controller (located in input.dart) from login.dart.
I created getter method to obtain, (controller.text) data but I have encountered with Initilazation Error.
How Can I acces controller text(which is basically user input) from another file?
input.dart
class InputAlanState extends State<InputAlan> {
late TextEditingController _emailKontroller;
late TextEditingController _sifreKontroller;
#override
void initState() {
super.initState();
_emailKontroller = TextEditingController();
_sifreKontroller = TextEditingController();
}
#override
void dispose() {
_emailKontroller.dispose();
_sifreKontroller.dispose();
super.dispose();
}
#override
Widget build(BuildContext context) {
if (widget.tur == "email") {
return Padding(
padding: const EdgeInsets.only(top: 50, left: 20, right: 20),
child: TextFormField(
controller: _emailKontroller,
autofocus: true,
decoration: const InputDecoration(
labelText: "E - Mail",
hintText: "E-Mail",
prefixIcon: Icon(Icons.email_outlined),
suffixIcon: Icon(Icons.lock),
border: OutlineInputBorder(
borderRadius: BorderRadius.all(Radius.circular(20.0)))),
),
);
} else if (widget.tur == "sifre") {
return Padding(
padding:
const EdgeInsets.only(top: 40, left: 20, right: 20, bottom: 15),
child: TextFormField(
controller: _sifreKontroller,
obscureText: true,
decoration: const InputDecoration(
labelText: "Password",
hintText: "Password",
prefixIcon: Icon(Icons.password_sharp),
suffixIcon: Icon(Icons.lock),
border: OutlineInputBorder(
borderRadius: BorderRadius.all(Radius.circular(20.0)))),
),
);
} else {
return Padding(
padding: const EdgeInsets.only(top: 50, left: 20, right: 20),
child: TextFormField(
decoration: const InputDecoration(
labelText: "E - Mail",
hintText: "E-Mail",
prefixIcon: Icon(Icons.email_outlined),
suffixIcon: Icon(Icons.lock),
border: OutlineInputBorder(
borderRadius: BorderRadius.all(Radius.circular(20.0)))),
),
);
}
}
}
login.py
Widget build(BuildContext context) {
return OutlinedButton(
onPressed: () {
InputAlan inputAlan = InputAlan("email");
String email = inputAlan.email;
String password = inputAlan.sifre;
Login login = login(email, sifre);
girisYap.girisYap(context);
},
child: const Text("SIGN IN"),
style: OutlinedButton.styleFrom(
primary: const Color(0xFF166FC0),
side: const BorderSide(color: Color(0xFF0FA9EA), width: 2),
shape: const RoundedRectangleBorder(
borderRadius: BorderRadius.all(Radius.circular(10)))),
);
}
}

Answer 1

to access variables from another state (in your case from InputAlanState) in flutter you have multiple options, the simplest way would be to use a GlobalKey, so in your code you can access InputAlanState's controllers from your login you can use this code in your OutlinedButton:
GlobalKey<InputAlanState> myKey = GlobalKey();
myKey.currentState!._emailKontroller; //here

Answer 2

You're putting a widget in a function parameter. In this way the widget cannot be rendered and it just can't work. I suggest you take a look at how to build flutter layouts to grasp the basics.
You probably want to build something like this:
enum Field { mail, password }
class MyApp extends StatelessWidget {
final TextEditingController mailController = TextEditingController();
final TextEditingController passwordController = TextEditingController();
#override
Widget build(BuildContext context) {
return MaterialApp(
home: Scaffold(
body: Column(
children: [
InputAlan(fieldType: Field.mail, textEditingController: mailController,),
InputAlan(fieldType: Field.password, textEditingController: passwordController,),
OutlinedButton(
onPressed: () {
String email = mailController.text;
String sifre = passwordController.text;
// Login login = login(email, sifre);
// girisYap.girisYap(context);
},
child: const Text("SIGN IN"),
style: OutlinedButton.styleFrom(
primary: const Color(0xFF166FC0),
side: const BorderSide(color: Color(0xFF0FA9EA), width: 2),
shape: const RoundedRectangleBorder(
borderRadius: BorderRadius.all(Radius.circular(10)))),
),
],
)
),
);
}
}
TextField widget
class InputAlan extends StatefulWidget {
const InputAlan({
Key? key,
required this.fieldType,
required this.textEditingController,
}) : super(key: key);
final Field fieldType;
final TextEditingController textEditingController;
#override
State<InputAlan> createState() => _InputAlanState();
}
class _InputAlanState extends State<InputAlan> {
#override
Widget build(BuildContext context) {
final isMailField = widget.fieldType == Field.mail;
return Padding(
padding: const EdgeInsets.only(top: 50, left: 20, right: 20),
child: TextFormField(
controller: widget.textEditingController,
autofocus: widget.fieldType == Field.mail,
obscureText: !isMailField,
decoration: InputDecoration(
labelText: isMailField ? "E - Mail" : "Password",
hintText: isMailField ? "E-Mail" : "Password",
prefixIcon:
Icon(isMailField ? Icons.email_outlined : Icons.password_sharp),
suffixIcon: const Icon(Icons.lock),
border: const OutlineInputBorder(
borderRadius: BorderRadius.all(Radius.circular(20.0)),
)),
),
);
}
}