FormBuilderDropdown broke inside futurebuilder - flutter

Question

I put the FormBuilderDropdown inside FutureBuilder so when I press on it will rebuild infinitely and will not enter the FormBuilderDropdown if anyone can give me a proper solution
and this is my code
FutureBuilder(
future: widget.fetchBrands(yearValue),
builder:
(BuildContext context, AsyncSnapshot snapshot) {
var snap = snapshot.data;
if (snapshot.connectionState ==
ConnectionState.waiting) {
return Center(
child: CircularProgressIndicator(),
);
}
if (snapshot.hasError) {
if (yearValue == null) {
return Container(
child: Text(
"Select the manufacture year to Select Brand",
style: TextStyle(
color: Colors.red[800],
fontSize: 16,
),
overflow: TextOverflow.visible,
),
);
}
return Center(
child: new Text('Error'),
);
}
snap.forEach((key, brand) {
brands.add(brand['make']);
});
brands = brands.toSet().toList();
brands.sort();
return
FormBuilderDropdown(
key: ValueKey("Brands"),
name: "Brands",
items: brands
.map(
(e) => DropdownMenuItem<String>(
child: Text(e),
value: e,
),
)
.toList(),
validator: FormBuilderValidators.compose(
[
FormBuilderValidators.required(
context,
)
],
),
decoration: InputDecoration(
labelText: 'Brands',
labelStyle:
Theme.of(context).textTheme.display1,
),
hint: Text('Select Brand'),
allowClear: true,
onChanged: (value) {
setState(() {
brandValue = value;
carValue = null;
carsName.clear();
});
},
);
},
),
before the new version of FormBuilder, this works well
I do temp solution that after I get the data I remove the future and build a new one without future but this solution not good enough because it takes two tap to open the dropdown

Answer 1

future: widget.fetchBrands(yearValue),
This means, every time build is called, you will start over and fetch the brands. You only want to fetch them once, yo you should only call the method once.
You want this line in initState where it runs only once:
brandsFuture = widget.fetchBrands(yearValue);
and then use that one future in your build method:
future: brandsFuture,
obviously you need to declare brandsFuture as a field in your state class.