Using search delegate for a listview generated from Future - flutter

Question

Here is my listview generated from a Future from a json file.
class _ChorusPage extends State<ChorusPage> {
static Future<List<Chorus>> getList() async {
var data = await rootBundle.loadString('assets/chorusJson.json');
var jsonMap = json.decode(data); // cast<Map<String, dynamic>>();
List<Chorus> choruses = [];
for (var c in jsonMap) {
Chorus chorus = Chorus.fromJson(c);
choruses.add(chorus);
}
// var = User.fromJson(parsedJson);
// choruses = jsonMap.map<Chorus>((json) => Chorus.fromJson(json)).toList();
print(choruses.length);
return choruses;
}
Widget build(BuildContext context) {
return new Scaffold(
appBar: new AppBar(title: new Text('Chorus'), actions: <Widget>[
IconButton(icon: Icon(Icons.search), onPressed: () {})
]),
body: Container(
child: FutureBuilder(
future: getList(),
builder: (BuildContext context, AsyncSnapshot snapshot) {
if (snapshot.data == null) {
return Container(
child: Center(child: CircularProgressIndicator()));
} else {
return ListView.builder(
itemCount: snapshot.data.length, // + 1,
itemBuilder: (BuildContext context, int index) {
return _listItem(index, snapshot);
});
}
})),
);
}
I am trying to implement a search function using the search delegate. The tutorial I am watching searches a List (https://www.youtube.com/watch?v=FPcl1tu0gDs&t=444s). What I have here is a Future. I am wondering how do you convert a future into a List. Or is there any other workaround.
class DataSearch extends SearchDelegate<String> {
Future<List<Chorus>> chorusList = _ChorusPage.getList();
// ????????????????????? How do I convert.
#override
List<Widget> buildActions(BuildContext context) {
// actions for app bar
return [IconButton(icon: Icon(Icons.clear), onPressed: () {})];
}
#override
Widget buildLeading(BuildContext context) {
// leading icon on the left of the app bar
return IconButton(
icon: AnimatedIcon(
icon: AnimatedIcons.menu_arrow,
progress: transitionAnimation,
),
onPressed: () {});
}
#override
Widget buildResults(BuildContext context) {
// show ssome result based on the selection
throw UnimplementedError();
}
#override
Widget buildSuggestions(BuildContext context) {
/*
final suggestionList = query.isEmpty ? recentChorus : chorus;
return ListView.builder(
itemBuilder: (context, index) => ListTile(
title: Text(suggestList[chorus]),
),
itemCount: suggestionList.length,
);
// show when someone searches for
*/
}
}

Answer 1

In my opinion you should set your chorusList and call somewhere your getList method with the .then method store the value inside your chorusList.
List<Chorus> chorusList;
_ChorusPage.getList().then((value) => chorusList);