Flutter API Resulting In Null - api

Question

currently working on a flutter project with API. I'm quite new to flutter,
My Code:
Results null.
Being working on it for quite some time but couldn't find a solution. First, try on a flutter app therefore I'm quite new to this, would appreciate any solutions or tips/resources.
All variables are resulting in null as you can see I tried printing them couldn't figure out why.
import 'dart:convert';
import 'package:flutter/material.dart';
import 'package:http/http.dart';
void main() => runApp(MyApp());
Future<Data> getData() async {
final response = await get("https://covid-api.com/api/reports?date=2020-03-25&iso=TUR&region_name=Turkey");
if(response.statusCode == 200) {
return Data.fromJson(jsonDecode(response.body));
} else {
throw Exception('Not Working');
}
}
class Data {
String date;
int confirmed;
int deaths;
int recovered;
int confirmedDiff;
int deathsDiff;
int recoveredDiff;
int active;
int activeDiff;
double fatalityRate;
Data({
this.date,
this.confirmed,
this.deaths,
this.recovered,
this.confirmedDiff,
this.deathsDiff,
this.recoveredDiff,
this.active,
this.activeDiff,
this.fatalityRate,
});
factory Data.fromJson(Map<String, dynamic> json) {
return Data(
confirmed: json['confirmed'],
deaths: json['deaths'],
recovered: json['recovered'],
confirmedDiff: json['confirmed_diff'],
deathsDiff: json['deaths_diff'],
recoveredDiff: json['recovered_diff'],
active: json['active'],
activeDiff: json['active_diff'],
fatalityRate: json['fatality_rate'],
);
}
Map<String, dynamic> toJson() {
final Map<String, dynamic> data = new Map<String, dynamic>();
data['date'] = this.date;
data['confirmed'] = this.confirmed;
data['deaths'] = this.deaths;
data['recovered'] = this.recovered;
data['confirmed_diff'] = this.confirmedDiff;
data['deaths_diff'] = this.deathsDiff;
data['recovered_diff'] = this.recoveredDiff;
data['active'] = this.active;
data['active_diff'] = this.activeDiff;
data['fatality_rate'] = this.fatalityRate;
return data;
}
}
class MyApp extends StatelessWidget {
final Future<Data> data = getData();
#override
Widget build(BuildContext context) {
return MaterialApp(
theme: ThemeData(primaryColor: Colors.red),
home: Scaffold(
appBar: AppBar(title: Text('COVID-19 Turkey')),
body: Center(
child: FutureBuilder<Data>(
future: data,
builder: (context, snapshot) {
print(snapshot.data.deaths);
print('wtf');
print(snapshot.data.deathsDiff);
print(snapshot.data.recovered);
if(snapshot.hasData){
return Text(snapshot.data.confirmed.toString());
} else if (snapshot.hasError) {
return Text('Error');
}
return Center(child: CircularProgressIndicator(),);
},
),)
)
);
}
}

Answer 1

I think the following is the right way of using FutureBuilder:
FutureBuilder(
future: getData(),
builder: (context, snapshot) {
if (!snapshot.hasData
&& snapshot.connectionState != ConnectionState.done) {
return Center(child: CircularProgressIndicator());
}
if(snapshot.hasData) {
return Text(snapshot.data.confirmed.toString());
} else if (snapshot.hasError) {
return Text('Error');
}
});
Hope it helps!

Answer 2

The problem is in your JSON parsing. On this line,
return Data.fromJson(jsonDecode(response.body));
I called your API and it is giving a Map in which there is a data field and then there is a list of objects in it.
Your getData function needs to be like this,
Future<Data> getData() async {
final response = await get("https://covid-api.com/api/reports?date=2020-03-25&iso=TUR&region_name=Turkey");
if(response.statusCode == 200) {
var data = jsonDecode(response.body);
var firstObj = (data['data'] as List<dynamic>).first;
return Data.fromJson(firstObj);
} else {
throw Exception('Not Working');
}
}
Hope this fixes it for you.