Difficulty in parsing JSON - flutter

Question

I want to develop a flutter app and I am finding it difficult to parse this JSON I have seen posts regarding this but I am finding it difficult to parse this. Help a beginner out! Here is the JSON link " https://api.covid19india.org/state_district_wise.json "
I am simply using:
Future getJsonDistrictData() async {
var response = await http.get(Uri.encodeFull(url1));
var converttojson1 = json.decode(response.body);
setState(() {
myData= converttojson1;
});
}
Text("${myData['Kerala']['districtData']['Thrissur']['confirmed']}")
But this would mean I have to write the same line for every district confirmed cases.
How should I proceed?

Answer 1

I have made the following example of an implementation you can use the parse the data from the URL in your question.
It can be simplified if you don't need the lastUpdatedTime and delta_confirmed since it looks like this is always the empty String and zero in the API.
import 'dart:convert';
class State {
final Map<String, DistrictData> districts = {};
State.fromJson(dynamic json) {
for (final district in json['districtData'].keys) {
districts[district as String] =
DistrictData.fromJson(json['districtData'][district]);
}
}
#override
String toString() => districts.toString();
}
class DistrictData {
final int confirmed;
final DateTime lastUpdatedTime;
final int delta_confirmed;
DistrictData(this.confirmed, this.lastUpdatedTime, this.delta_confirmed);
factory DistrictData.fromJson(dynamic json) => DistrictData(
json['confirmed'] as int,
(json['lastupdatedtime'].isEmpty as bool)
? null
: (DateTime.parse(json['lastupdatedtime'] as String)),
json['delta']['confirmed'] as int);
#override
String toString() =>
'{ confirmed: $confirmed, lastUpdatedTime: $lastUpdatedTime, delta_confirmed: $delta_confirmed }';
}
void main() {
final states = json.decode(input).map(
(String key, dynamic value) => MapEntry(key, State.fromJson(value)))
as Map<String, State>;
states.forEach((key, value) => print('$key : $value'));
/*
Kerala : {Thrissur: { confirmed: 13, lastUpdatedTime: null, delta_confirmed: 0 }, Alappuzha: { confirmed: 5, lastUpdatedTime: null, delta_confirmed: 0 }}
Delhi : {East Delhi: { confirmed: 1, lastUpdatedTime: null, delta_confirmed: 0 }}
*/
}
const input = '''
{
"Kerala": {
"districtData": {
"Thrissur": {
"confirmed": 13,
"lastupdatedtime": "",
"delta": {
"confirmed": 0
}
},
"Alappuzha": {
"confirmed": 5,
"lastupdatedtime": "",
"delta": {
"confirmed": 0
}
}
}
},
"Delhi": {
"districtData": {
"East Delhi": {
"confirmed": 1,
"lastupdatedtime": "",
"delta": {
"confirmed": 0
}
}
}
}
}
''';

Answer 2

Copy your JSON in this link(https://javiercbk.github.io/json_to_dart/) and get model Class.
Example:
For example your Model Class Name is CovidModel. As you get response from network call, pass data to you model class and get object like this:
CovidModel _covidModel = CovidModel.fromJson(response.data);
now you can use _covidModel to get inner objects and show result in app page.