I am getting an API response of the following type
[
{"name":"lakshay","id":"1217","type":"Staff","temperature":56.6,"date":"12-06-2020"},
{"name":"lakshay","id":"1217","type":"Staff","temperature":56.6,"date":"12-06-2020"},
.....
]
I need to parse the whole thing as List of objects, so that I can do something like
// conceptual //
array.map((obj)=>{
// computation //
})
I took help from here but it doesn't tell how to parse the outer array.
thanks for your time.
You can generate expected response class online using below link and create and save class in your project : https://javiercbk.github.io/json_to_dart/
For more details see this image :
class ApiRepositary {
Dio dio;
ApiRepositary() {
if (dio == null) {
BaseOptions options = new BaseOptions(
baseUrl: "your base url",
receiveDataWhenStatusError: true,
connectTimeout: 60*1000, // 60 seconds
receiveTimeout: 60*1000 // 60 seconds
);
dio = new Dio(options);
}
}
Future<List<UserResponse>> getUserDetails() async {
try {
Response res = await dio.get("/lookup/pollquestion/add your url here");
if (res.data.toString().isEmpty) {
throw Exception();
} else {
final List rawData = jsonDecode(jsonEncode(res.data));
List<UserResponse> response =
rawData.map((f) => UserResponse.fromJson(f)).toList();
return response;
}
} on DioError catch (dioError) {
throw Exception(dioError);
}
}
}
To call service in your class :
ApiRepositary().getUserDetails().then((response){
debugPrint("Login Success $response");
//manage your response here, here you will get arralist as a response
},
onError: (exception){
//Handle exception message
if(exception.message != null ){
debugPrint(exception.message);
}
},
);
You can copy paste run full code below
Step 1: parse with List<Payload> payloadList = payloadFromJson(jsonString); , you can see full code for detail Payload class definition
Step 2: For loop like this
payloadList.forEach((element) {
print(element.name);
print(element.id);
});
output
I/flutter (17660): lakshay
I/flutter (17660): 1217
I/flutter (17660): lakshay
I/flutter (17660): 1217
full code
import 'package:flutter/material.dart';
import 'dart:convert';
List<Payload> payloadFromJson(String str) =>
List<Payload>.from(json.decode(str).map((x) => Payload.fromJson(x)));
String payloadToJson(List<Payload> data) =>
json.encode(List<dynamic>.from(data.map((x) => x.toJson())));
class Payload {
Payload({
this.name,
this.id,
this.type,
this.temperature,
this.date,
});
String name;
String id;
String type;
double temperature;
String date;
factory Payload.fromJson(Map<String, dynamic> json) => Payload(
name: json["name"],
id: json["id"],
type: json["type"],
temperature: json["temperature"].toDouble(),
date: json["date"],
);
Map<String, dynamic> toJson() => {
"name": name,
"id": id,
"type": type,
"temperature": temperature,
"date": date,
};
}
void main() {
runApp(MyApp());
}
class MyApp extends StatelessWidget {
@override
Widget build(BuildContext context) {
return MaterialApp(
title: 'Flutter Demo',
theme: ThemeData(
primarySwatch: Colors.blue,
visualDensity: VisualDensity.adaptivePlatformDensity,
),
home: MyHomePage(title: 'Flutter Demo Home Page'),
);
}
}
class MyHomePage extends StatefulWidget {
MyHomePage({Key key, this.title}) : super(key: key);
final String title;
@override
_MyHomePageState createState() => _MyHomePageState();
}
class _MyHomePageState extends State<MyHomePage> {
int _counter = 0;
String jsonString = '''
[
{"name":"lakshay","id":"1217","type":"Staff","temperature":56.6,"date":"12-06-2020"},
{"name":"lakshay","id":"1217","type":"Staff","temperature":56.6,"date":"12-06-2020"}
]
''';
void _incrementCounter() {
List<Payload> payloadList = payloadFromJson(jsonString);
payloadList.forEach((element) {
print(element.name);
print(element.id);
});
setState(() {
_counter++;
});
}
@override
Widget build(BuildContext context) {
return Scaffold(
appBar: AppBar(
title: Text(widget.title),
),
body: Center(
child: Column(
mainAxisAlignment: MainAxisAlignment.center,
children: <Widget>[
Text(
'You have pushed the button this many times:',
),
Text(
'$_counter',
style: Theme.of(context).textTheme.headline4,
),
],
),
),
floatingActionButton: FloatingActionButton(
onPressed: _incrementCounter,
tooltip: 'Increment',
child: Icon(Icons.add),
),
);
}
}
Please use this response class
class YourResponse {
String name;
String id;
String type;
double temperature;
String date;
YourResponse({this.name, this.id, this.type, this.temperature, this.date});
YourResponse.fromJson(Map<String, dynamic> json) {
name = json['name'];
id = json['id'];
type = json['type'];
temperature = json['temperature'];
date = json['date'];
}
Map<String, dynamic> toJson() {
final Map<String, dynamic> data = new Map<String, dynamic>();
data['name'] = this.name;
data['id'] = this.id;
data['type'] = this.type;
data['temperature'] = this.temperature;
data['date'] = this.date;
return data;
}
}
Assuming
String jsonResponse = '''[
{"name":"lakshay","id":"1217","type":"Staff","temperature":56.6,"date":"12-06-2020"},
{"name":"lakshay","id":"1217","type":"Staff","temperature":56.6,"date":"12-06-2020"}
]''';
You could do something as below: Step 1) import 'dart:convert' package. Step 2 ) Add following lines:
List<dynamic> responses = jsonDecode(jsonResponse);
responses.forEach((obj){
print(obj['name']);
});
Remember the above code is a quick & dirty way get things working.you may lose many benefits of static type checking.It always recommended that use classes created as suggested by chunhunghan.
