Flutter snapshot data is empty - json

Question

I'm new in flutter, I try parse data from rest api.
Api return:
http://www.json-generator.com/api/json/get/cqwVqdOFrC?indent=2
Eg. Here get data from json api eg. length is 3231
class ApiService {
static Future<dynamic> _get(String url) async {
try {
final response = await http.get(url);
var jsonData = json.decode(response.body);
if (response.statusCode == 200) {
print(response.body.length); //3231
return jsonData;
} else {
return null;
}
}
}
but here is snapshot.hasData = False, Why?
return Scaffold(
appBar: AppBar(title: Text('Posts'),),
body: FutureBuilder(
future: ApiService.getUserList(),
builder: (BuildContext context, AsyncSnapshot snapshot) {
print(snapshot.hasData.toString()); //False no data
static Future<List<dynamic>> getUserList() async {
return await _get('${Urls.BASE_API_URL}');
}
Without items at the beginning of json all work fine. My web server return items at the beginning. Any solutions?

Answer 1

api returns Map<String, dynamic> not <List<dynamic>>
class ListaAbitudini extends StatefulWidget {
#override
State<StatefulWidget> createState() {
return new _ListaAbitudiniState();
}
}
class _ListaAbitudiniState extends State<ListaAbitudini> {
#override
Widget build(BuildContext context) {
return Scaffold(
appBar: AppBar(
title: Text('Posts'),
),
body: FutureBuilder(
future: ApiService.getUserList(),
builder: (BuildContext context, AsyncSnapshot snapshot) {
if(snapshot.hasData)
print("True");
return Container();
}));
}
}
class ApiService {
static Future<Map<String, dynamic>> getUserList() async {
return await _get('http://www.json-generator.com/api/json/get/cqwVqdOFrC?indent=2');
}
static Future<dynamic> _get(String url) async {
try {
final response = await http.get(url);
var jsonData = json.decode(response.body);
if (response.statusCode == 200) {
print(response.body.length); //3231
return jsonData;
} else {
return null;
}
} catch (e) {
print(e);
}
}
}

Answer 2

Have to try calling,
future: ApiService.getUserList().then((onValue) {
return onValue;
}

Answer 3

Usually you get hasData = false when hasError = true. Try to look for a snapahot error (snapshot.error)