Persistent bottom sheet form data - forms

Question

I have one form on a bottom sheet. It's opened on click of one button. It can be closed when the user clicks outside the form. I want to maintain the form data if the user reopens the form. I don't want to assign each form field value explicitly. Is there any other way of saving the form state and reusing it while creating the bottom sheet again?
void _modalBottomSheetMenu(BuildContext context, Widget form) async {
await showModalBottomSheet<dynamic>(
isDismissible: false,
isScrollControlled:true,
context: context,
shape: RoundedRectangleBorder(
borderRadius: BorderRadius.only(topLeft: Radius.circular(20), topRight: Radius.circular(20)),
),
backgroundColor: Colors.white,
builder: (BuildContext bc) {
return SingleChildScrollView(
child: Container(
padding:
EdgeInsets.only(bottom: MediaQuery.of(context).viewInsets.bottom),
child: Padding(
padding: const EdgeInsets.fromLTRB(20.0, 20.0, 20.0, 0.0),
child: form) // From with TextField inside
));}
);

Answer 1

So I finally found one of the best approaches for maintaining the state using Provider. I also explored other ways such as BLOC but it was very verbose for it. We can use BLOC for other cases but Provider is a better solution in case of a bottom sheet.
import 'package:flutter/material.dart';
import 'package:provider/provider.dart';
void main() => runApp(MyApp());
class MyApp extends StatelessWidget {
#override
Widget build(BuildContext context) {
return MaterialApp(
title: 'Bottom Sheet',
theme: ThemeData(
primarySwatch: Colors.blue,
),
home: ChangeNotifierProvider(
create: (context) => TitleDataNotifier(),
child: ButtomSheetScreen(),
),
);
}
}
class TitleDataNotifier with ChangeNotifier {
String _name;
String get name => _name;
set name(String name) {
_name = name;
notifyListeners();
}
}
class AddTaskScreen extends StatefulWidget {
final TitleDataNotifier valueProvider;
AddTaskScreen(this.valueProvider);
#override
_AddTaskScreenState createState() => _AddTaskScreenState();
}
class _AddTaskScreenState extends State<AddTaskScreen> {
final _controller = TextEditingController();
#override
void initState() {
super.initState();
_controller.text = widget.valueProvider.name;
}
void dispose() {
_controller.dispose();
super.dispose();
}
#override
void deactivate() {
widget.valueProvider.name = _controller.text;
super.deactivate();
}
#override
Widget build(BuildContext context) {
return Container(
padding: EdgeInsets.all(20.0),
decoration: BoxDecoration(
color: Colors.white,
borderRadius: BorderRadius.only(
topLeft: Radius.circular(20.0),
topRight: Radius.circular(20.0),
),
),
child: Column(
crossAxisAlignment: CrossAxisAlignment.stretch,
children: <Widget>[
Text(
'Add Task',
textAlign: TextAlign.center,
style: TextStyle(
fontSize: 30.0,
color: Colors.lightBlueAccent,
fontWeight: FontWeight.w700),
),
TextField(
controller: _controller,
autofocus: false,
textAlign: TextAlign.center,
onChanged: (newText) {
widget.valueProvider._name = newText;
},
),
FlatButton(
child: Text(
'Add',
style: TextStyle(color: Colors.white),
),
color: Colors.lightBlueAccent,
onPressed: () {
Navigator.pop(context);
},
)
],
),
);
}
}
class ButtomSheetScreen extends StatelessWidget {
void openBottomSheet(context) {
var valueProvider = Provider.of<TitleDataNotifier>(context, listen: false);
showModalBottomSheet<dynamic>(
context: context,
builder: (BuildContext context) {
return ChangeNotifierProvider.value(
value: valueProvider,
child: StatefulBuilder(
builder: (BuildContext context, StateSetter state) {
return Padding(
padding: EdgeInsets.only(
bottom: MediaQuery.of(context).viewInsets.bottom),
child: Wrap(
children: <Widget>[
AddTaskScreen(valueProvider),
],
),
);
}),
);
},
);
}
#override
Widget build(BuildContext context) {
return Scaffold(
appBar: AppBar(
title: Text(
"Bottom Sheet",
),
),
body: Center(
child: Container(
child: IconButton(
icon: const Icon(Icons.work),
onPressed: () {
openBottomSheet(context);
},
)),
));
}
}