I have been developing an app using Flutter and I am currently working on implementing a Dropdown Button that will display values received from a JSON response via an API built with Django.
Here is the JSON response:
[{"name": "FC1", "username": "admin"}, {"name": "FC2", "username": "admin"}]
This is the Object class being used:
class FoodCourt {
final String name;
FoodCourt(this.name);
}
This is the method for retrieving the data:
Future<List<FoodCourt>> _getFoodCourt() async {
var data = await http
.get("http://timetable-api-manipal.herokuapp.com/getfoodcourt");
var jsonData = json.decode(data.body);
List<FoodCourt> fcs = [];
for (var u in jsonData) {
FoodCourt fc = FoodCourt(u["name"]);
fcs.add(fc);
}
print(fcs);
return fcs;
}
Here is the implementation of the FutureBuilder Widget:
FutureBuilder(
future: _getFoodCourt(),
builder: (context, snapshot) {
return DropdownButton<String>(
hint: Text("Select"),
value: selectedFc,
onChanged: (newValue) {
setState(() {
selectedFc = newValue;
});
},
items: snapshot.data.map((fc) {
return DropdownMenuItem<String>(
child: Text(fc.name),
value: fc.name,
);
}));
}),
The error message displayed reads as follows:
I/flutter (31862): ══╡ EXCEPTION CAUGHT BY WIDGETS LIBRARY ╞═══════════════════════════════════════════════════════════
I/flutter (31862): The following assertion was thrown building FutureBuilder<List<FoodCourt>>(dirty, state:
I/flutter (31862): _FutureBuilderState<List<FoodCourt>>#3c097):
I/flutter (31862): type 'MappedListIterable<FoodCourt,
DropdownMenuItem<FoodCourt>>' is not a subtype of type
I/flutter (31862): 'List<DropdownMenuItem<FoodCourt>>'
I have attempted various solutions to this issue but to no avail. It would be greatly appreciated if someone could provide a sample code for a successful resolution!