Reuse Datepicker for different field values - flutter

Question

I'm trying to make my datepicker reusable, as I need three datepickers, that change different values that are stored in the same class, lets call it _object.date1 , date 2, date 3
To reuse my datepicker I tried the following and passed the variable to the datepicker that shall be changed. But then the field value isn't changed or stored and nothing happens, also no error. If I don't pass the value to _showAndroidDatePicker() and use the line in setState that I commented out below, it works properly. The Datepicker ist linked to the onTap of a TextFormField in a Form.
Can anyone explain to me what I'm missing here? It would be really great to make this reusable.
Many thanks!
void _showAndroidDatePicker(value) {
showDatePicker(
context: context,
builder: (BuildContext context, Widget child) {
return Theme(
data: ThemeData.light().copyWith(
primaryColor: Theme.of(context).primaryColor,
accentColor: Theme.of(context).primaryColor,
colorScheme:
ColorScheme.light(primary: Theme.of(context).primaryColor),
buttonTheme: ButtonThemeData(textTheme: ButtonTextTheme.primary),
),
child: child,
);
},
initialDate: DateTime.now(),
locale: Locale('de'),
firstDate: DateTime(1900),
helpText: 'Bitte wähle ein Datum aus',
lastDate: DateTime.now(),
).then<DateTime>(
(DateTime newDate) {
if (newDate != null) {
setState(() {
value = newDate.toIso8601String();
//Below code works if value isn't passed to datepicker, but I want it variable to avoid boilerplate
// _object.date1 =newDate.toIso8601String();
});
}
return;
},
);
}
Many thanks for your help!

Answer 1

You could pass it the controller and the focus node for the text field. Something like this:
datePickerListener(node, controller) {
if (node.hasFocus) {
node.unfocus();
showDatePicker(your setup).then((date){
var formatter = DateFormat('dd/MM/yyyy');
var formatted = formatter.format(date).toString();
controller.text = formatted;
});
}
}
Then:
FocusNode yourNode = FocusNode();
#override
void initState(){
yourNode.addListener(){
datePickerListener(yourNode, yourController);
};
}
TextFormField(
focusNode: yourNode,
controller: yourController,
)
Something like that. Just adjust to your needs.