Resetting TextfieldController for all textfields, using provider - flutter

Question

I'm having a problem trying to figuring out the proper way on how to do this. Basically in my app, I want to reset all the fields for "cleanup" by the user. I can reset everything, but the TextFields. The only way that I found to solve the problem is by using the if that you can see inside the Consumer. I don't think though it's the proper way on how to handle this type of thing.
I also thought to push inside my provider class all the controller and then reset them, but I think it's still too heavy. I'm trying to find the cleanest and lightest solution, even to learn what's the best practice in these situations.
Thanks in advance!
return Provider.of<Provider_Class>(context, listen: false).fields[_label] != null ? SizedBox(
height: 57.5,
child: Consumer<Provider_Class>(builder: (context, provider, child) {
if (provider.resetted == true) {
_controller.text = "";
}
return Material(
elevation: this.elev,
shadowColor: Colors.black,
borderRadius: new BorderRadius.circular(15),
animationDuration: new Duration(milliseconds: 500),
child: new TextField(
focusNode: _focusNode,
keyboardAppearance: Brightness.light,
style: Theme.of(context).textTheme.headline5,
controller: _controller,
keyboardType: TextInputType.number,
textAlign: TextAlign.end,
inputFormatters: <TextInputFormatter>[
LengthLimitingTextInputFormatter(8),
_whichLabel(widget.label),
],
decoration: new InputDecoration(
enabledBorder: new OutlineInputBorder(
borderRadius: new BorderRadius.circular(15),
borderSide: new BorderSide(width: 1.2, color: CliniLiliac300),
),
focusedBorder: new OutlineInputBorder(
borderRadius: new BorderRadius.circular(15),
borderSide: new BorderSide(width: 2.5, color: CliniLiliac300),
),
filled: true,
fillColor: Colors.white,
hintText: "0.0",
hintStyle: new TextStyle(fontSize: 15, color: Colors.black, fontFamily: "Montserrat"),
),
onChanged: (val) {
var cursorPos = _controller.selection;
val = val.replaceAll(",", ".");
if (val == "") {
provider.fields[_label] = 0.0;
} else if (double.parse(val) > provider.measure[_label] &&
provider.measure[_label] != 0) {
provider.fields[_label] % 1 == 0
? _controller.text = provider.fields[_label].toString().split(".")[0]
: _controller.text = provider.fields[_label].toString();
if (cursorPos.start > _controller.text.length) {
cursorPos = new TextSelection.fromPosition(
new TextPosition(offset: _controller.text.length),
);
}
_controller.selection = cursorPos;
} else {
provider.fields[_label] = double.parse(val);
}
provider.calculateResultRA();
},
),
);
}),
) : SizedBox();
}

Answer 1

Use TextFormField instead of TextField. TextFormField has several callbacks like validator, onSaved, onChanged, onEditingComplete, onSubmitted, ...
You can connect all your TextFormFields by wrapping it in a Form. This form should be given a GlobalKey so that you can identify the Form and call methods on FormState.
final _form = GlobalKey<FormState>();
#override
Widget build(BuildContext context) {
// ...
return Form(
key: _form,
child: // build Material with TextFormFields
);
}
Now to call onSaved on each TextFormField, you can call _form.currentState().save(). To reset every TextFormField you can call _form.currentState().reset().
You can get more information about how to build a Form and the functions you can call on FomState here:
https://flutter.dev/docs/cookbook/forms/validation
https://api.flutter.dev/flutter/widgets/FormState-class.html