How to save int data from TextFormField in Flutter - flutter

Question

I made some TextFormField, and I want to save the data in int when I press the FlatButton. When I press FlatButton, I want him to check whether the sum of TextFormField expenses and savings is not greater than TextFormField income. if the sum of the TextTormField expenses and savings is greater, I want to display errortext under the textformfield savings "your expenses and savings are greater than your income"
class BigNotePage extends StatefulWidget {
#override
_BigNotePageState createState() => _BigNotePageState();
}
class _BigNotePageState extends State<BigNotePage> {
final _formKey = GlobalKey<FormState>();
String _income;
String _expenses;
String _savings;
#override
Widget build(BuildContext context) {
return Container(
padding: kPading,
child: Column(
crossAxisAlignment: CrossAxisAlignment.start,
children: [
TitlePage('Big Note'),
Expanded(
child: Form(
key: _formKey,
child: Column(
crossAxisAlignment: CrossAxisAlignment.stretch,
mainAxisAlignment: MainAxisAlignment.center,
children: [
TxtField(
label: 'Income',
function: (value) => _income = value,
),
TxtField(
label: 'Expenses',
function: (value) => _expenses = value,
),
TxtField(
label: 'Savings',
function: (value) => _savings = value,
),
FlatButton(
onPressed: () {
int.parse(_income) >=
int.parse(_expenses) + int.parse(_savings)
? _formKey.currentState.save()
: print('null');
},
child: Text(
'WRITE THAT',
style: TextStyle(letterSpacing: 1.25),
),
color: Colors.yellow,
shape: RoundedRectangleBorder(
borderRadius: BorderRadius.circular(30.0),
),
),
],
),
),
),
Container(
width: 250.0,
child: Text(
'*if you get another income for this mounth, input the income again.',
style: TextStyle(fontSize: 12.0),
),
),
],
),
);
}
}
class TxtField extends StatelessWidget {
TxtField({this.label, this.function});
final String label;
final Function function;
#override
Widget build(BuildContext context) {
return Container(
padding: EdgeInsets.symmetric(vertical: 8.0),
child: TextFormField(
onSaved: function,
keyboardType: TextInputType.numberWithOptions(decimal: true),
decoration: InputDecoration(
labelText: label,
prefix: Container(
padding: EdgeInsets.all(8.0),
child: Text(
'IDR',
style:
TextStyle(color: Colors.black, fontWeight: FontWeight.bold),
),
),
),
),
);
}
}

Answer 1

Replace String values to the controller values
final _incomeController = TextEditingController();
final _expenseController = TextEditingController();
final _savingController = TextEditingController();
Also, add
bool _validate = false;
Convert String value to int of your TextField:
TextField(
controller: _incomeController,
label: 'Income',
decoration: InputDecoration(
errorText: _validate ? 'Your message' : null,
),
),
TextField(
controller: _expenseController ,
label: 'Expenses',
decoration: InputDecoration(
errorText: _validate ? 'Your message' : null,
),
),
TextField(
controller: _savingController,
label: 'Savings',
decoration: InputDecoration(
errorText: _validate ? 'Your message' : null,
),
),
Now FlatButton Logic:
onPressed: () {
String _income = _incomeController.text;
String _expenses = _expenseController.text;
String _savings = _savingController.text;
int.parse(_income) >=
int.parse(_expenses) + int.parse(_savings)
? _formKey.currentState.save()
: print('null');
},
Rest apply your logic wherever you want.