how to pass array of data from API into graph in flutter?

how to pass array of data from API into graph in flutter? - android

I have an issue while integrating an array of data from API into my graph, I have tried all other methods but I don't find any solution. How to Use model class to get API data and integrate it into a graph.
import 'dart:convert';
import 'package:chartapp/network/network_helper.dart';
import 'package:chartapp/src/Bar_Chart/bar_model.dart';
import 'package:flutter/material.dart';
import 'package:charts_flutter/flutter.dart' as charts;
import 'package:http/http.dart' as http;
import 'gender_model.dart';
class NetworkHelper {
Future<http.Response> post(String endpoint) async {
var url = Uri.parse(endpoint);
var response = await http.post(url, headers: {
'Authorization':
'token',
'Cookie': ''
});
return response;
}
}
class BarChartAPI extends StatefulWidget {
const BarChartAPI({Key? key}) : super(key: key);
#override
State<BarChartAPI> createState() => _BarChartAPIState();
}
class _BarChartAPIState extends State<BarChartAPI> {
List<Graphmodel> graph = [];
bool loading = true;
NetworkHelper _networkHelper = NetworkHelper();
#override
void initState() {
super.initState();
getData();
}
void getData() async {
var response = await _networkHelper.post(
"*********************************");
final tempdata = json.decode(response.body)['result']["meter"]
["performance"]["growth"]["graph-data"];
List data = tempdata
.map((e) => Graphmodel(name: e['name'], value: e['value']))
.toList();
print(tempdata);
print(data);
setState(() {
graph = data as List<Graphmodel>;
loading = false;
});
}
List<charts.Series<Graphmodel, String>> _createSampleData() {
return [
charts.Series<Graphmodel, String>(
data: graph ,
id: 'graph_data',
colorFn: (_, __) => charts.MaterialPalette.teal.shadeDefault,
domainFn: (Graphmodel graphmodel, _) => graphmodel.name,
measureFn: (Graphmodel graphmodel, _) => graphmodel.value,
)
];
}
#override
Widget build(BuildContext context) {
return Scaffold(
appBar: AppBar(
title: Text("Graph"),
),
body: Center(
child: loading
? CircularProgressIndicator()
: Container(
height: 300,
child: charts.BarChart(
_createSampleData(),
animate: true,
),
),
),
);
}
}
This is my console response
[1]: https://i.stack.imgur.com/Hkomh.png
The following is my class model
import 'dart:convert';
List<Graphmodel> graphmodelFromJson(String str) =>
List<Graphmodel>.from(json.decode(str).map((x) => Graphmodel.fromJson(x)));
String graphmodelToJson(List<Graphmodel> data) =>
json.encode(List<dynamic>.from(data.map((x) => x.toJson())));
class Graphmodel {
Graphmodel({
required this.name,
required this.value,
});
String name;
int value;
factory Graphmodel.fromJson(Map<String, dynamic> json) => Graphmodel(
name: json["name"],
value: json["value"],
);
Map<String, dynamic> toJson() => {
"name": name,
"value": value,
};
}

Related

asynchronous suspension after adding ChangeNotifierProxyProvider to my MutiProviders

I am passing the authentication token from Auth.dart file to Products.dart file to enable the app to fetch the Products in my database but the app is not able to fetch those,
I am very new to flutter any help would be appreciated
Thank you
here is my Auth.dart file
import 'dart:convert';
import 'package:flutter/widgets.dart';
import 'package:http/http.dart' as http;
import '../models/http_exceptions.dart';
class Auth with ChangeNotifier {
String _token;
DateTime _expiryDate;
String _userId;
bool get isAuth {
return token != null;
}
String get token {
if (_expiryDate != null &&
_expiryDate.isAfter(DateTime.now()) &&
_token != null) {
return _token;
}
return null;
}
Future<void> _authenticate(
String email, String password, String urlSegment) async {
final url = Uri.parse(
'https://identitytoolkit.googleapis.com/v1/accounts:$urlSegment?key=<key>',
);
try {
final response = await http.post(
url,
body: json.encode(
{
'email': email,
'password': password,
'returnSecureToken': true,
},
),
);
final responseData = json.decode(response.body);
if (responseData['error'] != null) {
throw HttpEception(responseData['error']['message']);
}
_token = responseData['idToken'];
_userId = responseData['localId'];
_expiryDate = DateTime.now().add(
Duration(
seconds: int.parse(responseData['expiresIn']),
),
);
notifyListeners();
} catch (error) {
throw error;
}
}
Future<void> signup(String email, String password) async {
return _authenticate(email, password, 'signUp');
}
Future<void> login(String email, String password) async {
return _authenticate(email, password, 'signInWithPassword');
}
}
Here is my Products.dart file, which has the Product class which is
import 'package:flutter/foundation.dart';
import 'package:http/http.dart' as http;
import 'dart:convert';
import 'package:shop_app/models/http_exceptions.dart';
class Product with ChangeNotifier {
final String id;
final String title;
final String description;
final double price;
final String imageUrl;
bool isFavorite;
Product({
#required this.id,
#required this.title,
#required this.description,
#required this.price,
#required this.imageUrl,
this.isFavorite = false,
});
Future<void> toggleFavoriteStatus() async {
final url = Uri.https(
'<confedential>.firebaseio.com',
'/products/$id.json',
);
final oldStatus = isFavorite;
isFavorite = !isFavorite;
notifyListeners();
final response = await http.patch(
url,
body: json.encode(
{
'isFavorite': isFavorite,
},
),
);
if (response.statusCode >= 400) {
isFavorite = oldStatus;
notifyListeners();
throw HttpEception('Could Not Change To Favourite');
}
}
}
import 'dart:convert';
import 'package:flutter/material.dart';
import 'package:http/http.dart' as http;
import 'package:shop_app/models/http_exceptions.dart';
import './product.dart';
class Products with ChangeNotifier {
List<Product> _items = [];
final String authToken;
Products(this.authToken,this._items);
List<Product> get items {
return [..._items];
}
List<Product> get favoriteItems {
return _items.where((prodItem) => prodItem.isFavorite).toList();
}
Product findById(String id) {
return _items.firstWhere((prod) => prod.id == id);
}
Future<void> fetchAndSetProducts() async {
final url = Uri.https(
'<details>.firebaseio.com',
'/products.json?auth=$authToken',
);
try {
final response = await http.get(url);
// print(json.decode(response.body));
final extractedData = json.decode(response.body) as Map<String, dynamic>;
if (extractedData == null) {
return;
}
final List<Product> loadedProducts = [];
extractedData.forEach((productId, productData) {
loadedProducts.add(
Product(
id: productId,
title: productData['title'],
description: productData['description'],
price: productData['price'],
isFavorite: productData['isFavourite'],
imageUrl: productData['imageUrl'],
),
);
});
_items = loadedProducts;
notifyListeners();
} catch (error) {
throw error;
}
}
Future<void> addProduct(Product product) async {
var url = Uri.https(
'<details>.firebaseio.com',
'/products.json',
);
try {
final response = await http.post(
url,
body: json.encode(
{
'title': product.title,
'description': product.description,
'imageUrl': product.imageUrl,
'price': product.price,
'isFavourite': product.isFavorite,
},
),
);
final newProduct = Product(
title: product.title,
description: product.description,
price: product.price,
imageUrl: product.imageUrl,
id: json.decode(response.body)['name'],
);
_items.add(newProduct);
notifyListeners();
} catch (error) {
throw error;
}
}
Future<void> updateProduct(String id, Product newProduct) async {
final prodIndex = _items.indexWhere((prod) => prod.id == id);
if (prodIndex >= 0) {
final url = Uri.https(
'<details>.firebaseio.com',
'/products/$id.json',
);
http.patch(
url,
body: json.encode(
{
'title': newProduct.title,
'description': newProduct.description,
'imageUrl': newProduct.imageUrl,
'price': newProduct.price,
},
),
);
_items[prodIndex] = newProduct;
notifyListeners();
} else {
print('...');
}
}
Future<void> deleteProduct(String id) async {
final url = Uri.https(
'<details>.firebaseio.com',
'/products/$id.json',
);
final exisitingProductIndex = _items.indexWhere((prod) => prod.id == id);
var exisitingProduct = _items[exisitingProductIndex];
_items.removeAt(exisitingProductIndex);
notifyListeners();
final response = await http.delete(url);
if (response.statusCode >= 400) {
_items.insert(exisitingProductIndex, exisitingProduct);
notifyListeners();
throw HttpEception('Could Not Delete Product.');
}
exisitingProduct = null;
}
}
And finally the main.dart file which uses all this stuff
import 'package:flutter/material.dart';
import 'package:provider/provider.dart';
import './providers/auth.dart';
import './screens/cart_screen.dart';
import './screens/products_overview_screen.dart';
import './screens/product_detail_screen.dart';
import './providers/products.dart';
import './providers/cart.dart';
import './providers/orders.dart';
import './screens/orders_screen.dart';
import './screens/user_products_screen.dart';
import './screens/edit_product_screen.dart';
import './screens/auth_screen.dart';
void main() => runApp(MyApp());
class MyApp extends StatelessWidget {
#override
Widget build(BuildContext context) {
return MultiProvider(
// Defining these providers for lisening to changes in the data
providers: [
ChangeNotifierProvider.value(
value: Auth(),
),
// First parameter is the type of data that we depened on and second is the data that we arre passing
ChangeNotifierProxyProvider<Auth, Products>(
update: (ctx, auth, previousProducts) => Products(
auth.token,
previousProducts == null ? [] : previousProducts.items,
),
),
ChangeNotifierProvider.value(
value: Cart(),
),
ChangeNotifierProvider.value(
value: Orders(),
),
],
child: Consumer<Auth>(
builder: (context, auth, _) => MaterialApp(
title: 'MyShop',
theme: ThemeData(
primarySwatch: Colors.purple,
accentColor: Colors.deepOrange,
fontFamily: 'Lato',
),
// home: ProductsOverviewScreen(),
home: auth.isAuth ? ProductsOverviewScreen() : AuthScreen(),
routes: {
ProductDetailScreen.routeName: (ctx) => ProductDetailScreen(),
CartScreen.routeName: (ctx) => CartScreen(),
OrdersScreen.routeName: (ctx) => OrdersScreen(),
UserProductsScreen.routeName: (ctx) => UserProductsScreen(),
EditProductScreen.routeName: (ctx) => EditProductScreen(),
},
),
),
);
}
}

Just added create into ChangeNotifierProxyProvider
ChangeNotifierProxyProvider<Auth, Products>(
create: (_)=>Products('',[]),
update: (ctx, auth, previousProducts) => Products(
auth.token,
previousProducts == null ? [] : previousProducts.items,
),
),
and changed the url string in Products.dart file
Uri url = Uri.parse(
'https://<some_details>.firebaseio.com/products.json?auth=$authToken');

Error: Could not find the correct Provider<AuthState> above this AuthPage Widget

ERROR:
══╡ EXCEPTION CAUGHT BY WIDGETS LIBRARY ╞═══════════════════════════════════════════════════════════
The following ProviderNotFoundException was thrown building AuthPage(dirty, state:
_AuthPageState#7ac1c):
Error: Could not find the correct Provider above this AuthPage Widget
This happens because you used a BuildContext that does not include the provider
of your choice. There are a few common scenarios:
You added a new provider in your main.dart and performed a hot-reload.
To fix, perform a hot-restart.
The provider you are trying to read is in a different route.
Providers are "scoped". So if you insert of provider inside a route, then
other routes will not be able to access that provider.
You used a BuildContext that is an ancestor of the provider you are trying to read.
Make sure that AuthPage is under your MultiProvider/Provider.
This usually happens when you are creating a provider and trying to read it immediately.
For example, instead of:
Widget build(BuildContext context) {
return Provider<Example>(
create: (_) => Example(),
// Will throw a ProviderNotFoundError, because `context` is associated
// to the widget that is the parent of `Provider<Example>`
child: Text(context.watch<Example>()),
),
}
consider using builder like so:
Widget build(BuildContext context) {
return Provider<Example>(
create: (_) => Example(),
// we use `builder` to obtain a new `BuildContext` that has access to the provider
builder: (context) {
// No longer throws
return Text(context.watch<Example>()),
}
),
}
My Code:
AuthPage.dart:-
import 'package:first_app/pages/auth/bloc/auth_state.dart';
import 'package:first_app/pages/auth/widgets/auth_button.dart';
import 'package:first_app/pages/auth/widgets/otp_page.dart';
import 'package:first_app/pages/auth/widgets/phone_page.dart';
import 'package:first_app/pages/auth/widgets/set_up_account.dart';
import 'package:flutter/material.dart';
import 'package:flutter_bloc/flutter_bloc.dart';
import 'package:provider/provider.dart';
class AuthPage extends StatefulWidget {
final int page;
final String? uid;
const AuthPage({
Key? key,
this.page = 0,
this.uid,
}) : super(key: key);
#override
_AuthPageState createState() => _AuthPageState();
}
class _AuthPageState extends State<AuthPage> {
#override
Widget build(BuildContext context) {
final state = Provider.of<AuthState>(context);
final screenSize = MediaQuery.of(context).size;
return
Builder(builder: (context) {
return Stack(
children: [
Container(
height: screenSize.height,
width: screenSize.width,
color: Colors.white,
child: PageView(
controller: state.controller,
onPageChanged: state.onPageChanged,
physics: NeverScrollableScrollPhysics(),
children: [
PhonePage(),
OtpPage(),
SetUpAccount(),
],
),
),
AuthButton(),
],
);
});
}
}
class AuthPageWidget extends StatelessWidget {
final int page;
final String? uid;
const AuthPageWidget({
Key? key,
required this.page,
this.uid,
}) : super(key: key);
#override
Widget build(BuildContext context) {
final state = AuthState(page, uid ?? '');
return ChangeNotifierProvider(
create: (_) => state,
child: ChangeNotifierProvider.value(
value: state,
child: AuthPage(page: page, uid: uid),
),
);
}
}
AuthState.dart
import 'dart:async';
import 'package:first_app/models/user.dart';
import 'package:first_app/repositories/user_repository.dart';
import 'package:first_app/services/auth.dart';
import 'package:first_app/services/map_services.dart';
import 'package:cloud_firestore/cloud_firestore.dart';
import 'package:flutter/material.dart';
enum PhoneAuthState { initial, success, loading, codeSent, error }
/*part of 'auth_bloc.dart';
abstract class AuthState extends Equatable {
const AuthState();
#override
List<Object> get props => [];
}*/
class AuthState extends ChangeNotifier {
final authService = AuthService.instance;
final userRepo = UserRepository.instance;
PhoneAuthState _phoneAuthState = PhoneAuthState.initial;
String verificationId = '';
TextEditingController phoneController = TextEditingController();
TextEditingController otpController = TextEditingController();
TextEditingController firstNameController = TextEditingController();
TextEditingController lastNameController = TextEditingController();
TextEditingController emailController = TextEditingController();
TextEditingController licensePlateController = TextEditingController();
TextEditingController vehicleColorController = TextEditingController();
TextEditingController vehicleTypeController = TextEditingController();
TextEditingController vehicleManufacturersController = TextEditingController();
Roles role = Roles.passenger;
PageController? controller;
int pageIndex = 0;
String uid = '';
int timeOut = 30;
bool get isRoleDriver => role == Roles.driver;
AuthState(int page, String uid) {
this.uid = uid;
controller = PageController(initialPage: page);
pageIndex = page;
notifyListeners();
siginCurrentUser();
}
PhoneAuthState get phoneAuthState => _phoneAuthState;
set changeRoleState(int value) {
role = Roles.values[value];
notifyListeners();
}
set phoneAuthStateChange(PhoneAuthState phoneAuthState) {
_phoneAuthState = phoneAuthState;
notifyListeners();
}
void animateToNextPage(int page) {
controller!.animateToPage(page, duration: Duration(milliseconds: 400), curve: Curves.easeIn);
pageIndex = page;
notifyListeners();
}
void onPageChanged(int value) {
pageIndex = value;
notifyListeners();
}
Future<void> signUp() async {
phoneAuthStateChange = PhoneAuthState.loading;
final address = await MapService.instance?.getCurrentPosition();
try {
final user = User(
uid: uid,
isActive: true,
firstname: firstNameController.text,
lastname: lastNameController.text,
email: emailController.text,
createdAt: DateTime.now(),
isVerified: true,
licensePlate: licensePlateController.text,
phone: "234${phoneController.text}",
vehicleType: vehicleTypeController.text,
vehicleColor: vehicleColorController.text,
vehicleManufacturer: vehicleManufacturersController.text,
role: role,
latlng: address?.latLng,
);
await userRepo.setUpAccount(user);
phoneAuthStateChange = PhoneAuthState.success;
} on FirebaseException catch (e) {
print(e.message);
phoneAuthStateChange = PhoneAuthState.error;
}
}
Future<void> phoneNumberVerification(String phone) async {
await AuthService.instance!.verifyPhoneSendOtp(phone, completed: (credential) async {
if (credential.smsCode != null && credential.verificationId != null) {
verificationId = credential.verificationId ?? '';
notifyListeners();
await verifyAndLogin(credential.verificationId!, credential.smsCode!, phoneController.text);
}
}, failed: (error) {
phoneAuthStateChange = PhoneAuthState.error;
}, codeSent: (String id, int? token) {
verificationId = id;
notifyListeners();
phoneAuthStateChange = PhoneAuthState.codeSent;
codeSentEvent();
print('code sent $id');
}, codeAutoRetrievalTimeout: (id) {
verificationId = id;
notifyListeners();
phoneAuthStateChange = PhoneAuthState.codeSent;
animateToNextPage(1);
print('timeout $id');
});
animateToNextPage(1);
notifyListeners();
}
Future<void> verifyAndLogin(String verificationId, String smsCode, String phone) async {
phoneAuthStateChange = PhoneAuthState.loading;
final uid = await authService?.verifyAndLogin(verificationId, smsCode, phone);
await userRepo.getUser(uid);
this.uid = uid ?? '';
animateToNextPage(2);
notifyListeners();
phoneAuthStateChange = PhoneAuthState.success;
print('completed');
}
Future<void> siginCurrentUser() async {
await userRepo.signInCurrentUser();
}
Future<void> codeSentEvent() async {
animateToNextPage(1);
_startCountDown();
}
void _startCountDown() {
Timer.periodic(Duration(seconds: 1), (timer) {
if (timer.tick > 30) {
timer.cancel();
} else {
--timeOut;
}
notifyListeners();
});
}
}
main.dart
import 'package:first_app/pages/home/home.dart';
import 'package:first_app/repositories/user_repository.dart';
import 'package:first_app/ui/theme.dart';
import 'package:firebase_core/firebase_core.dart';
import 'package:flutter/material.dart';
void main() async {
WidgetsFlutterBinding.ensureInitialized();
await Firebase.initializeApp();
runApp(MyApp());
}
class MyApp extends StatefulWidget {
#override
_MyAppState createState() => _MyAppState();
}
class _MyAppState extends State<MyApp> {
#override
void initState() {
UserRepository.instance.signInCurrentUser();
super.initState();
}
#override
Widget build(BuildContext context) {
return MaterialApp(
title: 'BrilliantDrive',
theme: CityTheme.theme,
home: HomePage(),
);
}
}

Initialize your provider 1st. Refer this https://stackoverflow.com/a/68418866/16467763.
void main() async {
WidgetsFlutterBinding.ensureInitialized();
await Firebase.initializeApp();
runApp(
MultiProvider(
providers: [
ChangeNotifierProvider<AuthState>(
create: (context) => AuthState(),
),
],
child: MyApp(),
),
);
}

class AuthPageWidget extends StatelessWidget {
final int page;
final String? uid;
const AuthPageWidget({
Key? key,
required this.page,
this.uid,
}) : super(key: key);
#override
Widget build(BuildContext context) {
final state = AuthState(page, uid ?? '');
return ChangeNotifierProvider(
create: (_) => state,
child: ChangeNotifierProvider.value(
value: state,
child: AuthPage(page: page, uid: uid),
),
);
}
}
You should move the ChangeNotifierProvider to your main.dart like this
void main() async {
WidgetsFlutterBinding.ensureInitialized();
await Firebase.initializeApp();
final state = AuthState(page, uid ?? '');
runApp(
MaterialApp(
debugShowCheckedModeBanner: false,
home: ChangeNotifierProvider(
create: (_) => state,
child: AuthPage(page: page, uid: uid),
),
),
);
}
OR
class SomeWidget extends StatelessWidget {
#override
Widget build(BuildContext context) {
return MaterialApp(
debugShowCheckedModeBanner: false,
home: ChangeNotifierProvider(
create: (_) => state,
child: ChangeNotifierProvider.value(
value: state,
child: AuthPage(page: page, uid: uid),
),
)
),
);
}
}

In FLutter trying to get JSON had this problem: [ LateInitializationError: Field '_userData#577066488' has not been initialized]

I am trying to show the JSON data from a URL to my Flutter application and haven't found any solution yet. because i have the error:
[LateInitializationError: Field '_userData#577066488' has not been initialized]
How to show this data in the ListView in Flutter?
Here is My Complete Project Flutter:
The Url Parse:
http://jsonplaceholder.typicode.com/users
Main.dart
import 'package:flutter/material.dart';
import 'json_parse_demo.dart';
void main() {
runApp(const HomeApp());
}
class HomeApp extends StatelessWidget {
const HomeApp({Key? key}) : super(key: key);
#override
Widget build(BuildContext context) {
return const MaterialApp(
debugShowCheckedModeBanner: false,
home: JsonParseDemo(),
);
}
}
users.dart
// To parse this JSON data, do
//
// final users = usersFromJson(jsonString);
// ignore_for_file: file_names
import 'dart:convert';
User userFromJson(String str) => User.fromJson(json.decode(str));
String userToJson(User data) => json.encode(data.toJson());
class User {
User({
required this.user,
});
List<UserElement> user;
factory User.fromJson(Map<String, dynamic> json) => User(
user: List<UserElement>.from(
json["User"].map((x) => UserElement.fromJson(x))),
);
Map<String, dynamic> toJson() => {
"User": List<dynamic>.from(user.map((x) => x.toJson())),
};
}
class UserElement {
UserElement({
required this.id,
required this.name,
required this.username,
required this.email,
required this.address,
required this.phone,
required this.website,
required this.company,
});
int id;
String name;
String username;
String email;
Address address;
String phone;
String website;
Company company;
factory UserElement.fromJson(Map<String, dynamic> json) => UserElement(
id: json["id"],
name: json["name"],
username: json["username"],
email: json["email"],
address: Address.fromJson(json["address"]),
phone: json["phone"],
website: json["website"],
company: Company.fromJson(json["company"]),
);
Map<String, dynamic> toJson() => {
"id": id,
"name": name,
"username": username,
"email": email,
"address": address.toJson(),
"phone": phone,
"website": website,
"company": company.toJson(),
};
}
class Address {
Address({
required this.street,
required this.suite,
required this.city,
required this.zipcode,
required this.geo,
});
String street;
String suite;
String city;
String zipcode;
Geo geo;
factory Address.fromJson(Map<String, dynamic> json) => Address(
street: json["street"],
suite: json["suite"],
city: json["city"],
zipcode: json["zipcode"],
geo: Geo.fromJson(json["geo"]),
);
Map<String, dynamic> toJson() => {
"street": street,
"suite": suite,
"city": city,
"zipcode": zipcode,
"geo": geo.toJson(),
};
}
class Geo {
Geo({
required this.lat,
required this.lng,
});
String lat;
String lng;
factory Geo.fromJson(Map<String, dynamic> json) => Geo(
lat: json["lat"],
lng: json["lng"],
);
Map<String, dynamic> toJson() => {
"lat": lat,
"lng": lng,
};
}
class Company {
Company({
required this.name,
required this.catchPhrase,
required this.bs,
});
String name;
String catchPhrase;
String bs;
factory Company.fromJson(Map<String, dynamic> json) => Company(
name: json["name"],
catchPhrase: json["catchPhrase"],
bs: json["bs"],
);
Map<String, dynamic> toJson() => {
"name": name,
"catchPhrase": catchPhrase,
"bs": bs,
};
}
servicios.dart
import 'package:http/http.dart' as http;
import 'users.dart';
class Services {
//
static Uri uri = Uri.parse('http://jsonplaceholder.typicode.com/users');
static Future<List<User>> getUsers() async {
try {
final response = await http.get(uri);
if (200 == response.statusCode) {
final List<User> users = userFromJson(response.body) as List<User>;
return users;
} else {
return <User>[];
}
} catch (e) {
return <User>[];
}
}
}
json_parse_demo.dart
// ignore_for_file: unnecessary_null_comparison
import 'package:flutter/material.dart';
import 'users.dart';
import 'servicios.dart';
class JsonParseDemo extends StatefulWidget {
//
const JsonParseDemo({Key? key}) : super(key: key);
#override
_JsonParseDemoState createState() => _JsonParseDemoState();
}
class _JsonParseDemoState extends State<JsonParseDemo> {
//
late List<User> _users;
// late bool _loading;
bool _loading = true;
#override
void initState() {
super.initState();
_loading = true;
Services.getUsers().then((users) {
setState(() {
_users = users;
_loading = false;
});
});
}
#override
Widget build(BuildContext context) {
return Scaffold(
appBar: AppBar(
title: Text(_loading ? 'Loading...' : 'Users'),
),
body: Container(
color: Colors.white,
child: ListView.builder(
itemCount: null == _users ? 0 : _users.length,
itemBuilder: (context, index) {
UserElement user = _users[index] as UserElement;
return ListTile(
title: Text(user.name),
subtitle: Text(user.email),
);
},
),
),
);
}
}

Make a function of future with async return then call it function in initstate (){}.
Because getUser api call is a asynchronous task.
Change your code like this.
#override
void initState() {
super.initState();
_loading = true;
getUserApiCall ();
}
Future getUserApiCall() async{
return await Services.getUsers().then((users) {
setState(() {
_users = users;
_loading = false;
});
});
}
If you facing any issues let me know

Unhandled Exception: type '_InternalLinkedHashMap<String, dynamic>' is not a subtype of type 'Iterable<dynamic>' why this error coming

how to load value from api to fields when the api response json is complex ?
{
"agent":{
"agent_name": "Shamsudheen",
"agent_phone": "0581476710",
"email": "shamsu#gmail.com",
},
"tenants": [
{
"entity_id": "152",
"user_id": "37",
},
{
"entity_id": "153",
"user_id": "37",
},
{
"entity_id": "150",
"user_id": "37",
}
]
}
and this is my model class
class AgentDetailsInfo {
String name;
String email;
String mobile;
List<Tenantdetails> list;
AgentDetailsInfo(
{
this.name,
this.email,
this.mobile,
this.list
});
factory AgentDetailsInfo.fromJson(Map<String, dynamic> json) {
return new AgentDetailsInfo(
name: json['agent']['agent_name'],
email: json['agent']['email'],
mobile: json['agent']['agent_phone']
List:json[’tenants’]
);
}
}
class Tenantdetails {
String entity;
String userid;
Tenantdetails({
this.entity,
this.userid,
});
factory Tenantdetails.fromJson(Map<String, dynamic> json) {
return new Tenantdetails(
entity: json['tenants']['entity_id'],
userid: json['tenants']['user_id'],
);
}
}
and am calling api like this response coming perfectly but value is nitf
List<AgentDetailsInfo> _list;
Future getAgentDetails(String agentId) async {
String tokenKey = await SharedPrefUtils.readPrefStr("token");
String url =
Constants.BASEURL + Constants.KEYWORD_GET_AGENT_DETAILS + agentId;
final response = await http.get(
url,
headers: {"Accept": "application/json", "Authorization": tokenKey},
);
var response = jsonDecode(response.body);
_list = List();
for (Map agentinfo in response) {
_list.add(AgentDetailsInfo.fromJson(agentinfo));
}
}
but its not loading in my text view showing error
"_InternalLinkedHashMap<String, dynamic>' is not a subtype of type 'Iterable"
Text(_list[0].name,
))

You can copy paste run full code below
Step 1: Based on your JSON String, you need class Agent, see full code below
Step 2: You can parse with agentDetailsInfoFromJson(response.body);
code snippet
AgentDetailsInfo agentDetailsInfoFromJson(String str) =>
AgentDetailsInfo.fromJson(json.decode(str));
...
class AgentDetailsInfo {
AgentDetailsInfo({
this.agent,
this.tenants,
});
Agent agent;
List<Tenantdetails> tenants;
...
class Agent {
Agent({
this.agentName,
this.agentPhone,
this.email,
});
String agentName;
String agentPhone;
String email;
working demo
full code
import 'package:flutter/material.dart';
import 'package:http/http.dart' as http;
import 'dart:convert';
AgentDetailsInfo agentDetailsInfoFromJson(String str) =>
AgentDetailsInfo.fromJson(json.decode(str));
String agentDetailsInfoToJson(AgentDetailsInfo data) =>
json.encode(data.toJson());
class AgentDetailsInfo {
AgentDetailsInfo({
this.agent,
this.tenants,
});
Agent agent;
List<Tenantdetails> tenants;
factory AgentDetailsInfo.fromJson(Map<String, dynamic> json) =>
AgentDetailsInfo(
agent: Agent.fromJson(json["agent"]),
tenants: List<Tenantdetails>.from(
json["tenants"].map((x) => Tenantdetails.fromJson(x))),
);
Map<String, dynamic> toJson() => {
"agent": agent.toJson(),
"tenants": List<dynamic>.from(tenants.map((x) => x.toJson())),
};
}
class Agent {
Agent({
this.agentName,
this.agentPhone,
this.email,
});
String agentName;
String agentPhone;
String email;
factory Agent.fromJson(Map<String, dynamic> json) => Agent(
agentName: json["agent_name"],
agentPhone: json["agent_phone"],
email: json["email"],
);
Map<String, dynamic> toJson() => {
"agent_name": agentName,
"agent_phone": agentPhone,
"email": email,
};
}
class Tenantdetails {
Tenantdetails({
this.entityId,
this.userId,
});
String entityId;
String userId;
factory Tenantdetails.fromJson(Map<String, dynamic> json) => Tenantdetails(
entityId: json["entity_id"],
userId: json["user_id"],
);
Map<String, dynamic> toJson() => {
"entity_id": entityId,
"user_id": userId,
};
}
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> {
Function _future;
Future<AgentDetailsInfo> getAgentDetails(String agentId) async {
print(agentId);
/*String tokenKey = await SharedPrefUtils.readPrefStr("token");
String url = Constants.BASEURL + Constants.KEYWORD_GET_AGENT_DETAILS + agentId;
final response = await http.get(
url,
headers: {"Accept": "application/json", "Authorization": tokenKey},
);*/
String jsonString = '''
{
"agent":{
"agent_name": "Shamsudheen",
"agent_phone": "0581476710",
"email": "shamsu#gmail.com"
},
"tenants": [
{
"entity_id": "152",
"user_id": "37"
},
{
"entity_id": "153",
"user_id": "37"
},
{
"entity_id": "150",
"user_id": "37"
}
]
}
''';
http.Response response = http.Response(jsonString, 200);
if (response.statusCode == 200) {
return agentDetailsInfoFromJson(response.body);
}
}
#override
void initState() {
_future = getAgentDetails;
super.initState();
}
#override
Widget build(BuildContext context) {
return Scaffold(
appBar: AppBar(
title: Text(widget.title),
),
body: FutureBuilder(
future: _future("test"),
builder: (context, AsyncSnapshot<AgentDetailsInfo> snapshot) {
switch (snapshot.connectionState) {
case ConnectionState.none:
return Text('none');
case ConnectionState.waiting:
return Center(child: CircularProgressIndicator());
case ConnectionState.active:
return Text('');
case ConnectionState.done:
if (snapshot.hasError) {
return Text(
'${snapshot.error}',
style: TextStyle(color: Colors.red),
);
} else {
return ListView.builder(
itemCount: snapshot.data.tenants.length,
itemBuilder: (context, index) {
return Card(
elevation: 6.0,
child: Padding(
padding: const EdgeInsets.only(
top: 6.0,
bottom: 6.0,
left: 8.0,
right: 8.0),
child: Row(
crossAxisAlignment: CrossAxisAlignment.start,
children: <Widget>[
Text(snapshot.data.agent.agentName
.toString()),
Spacer(),
Text(snapshot.data.tenants[index].userId
.toString()),
Spacer(),
Text(snapshot.data.tenants[index].entityId),
],
),
));
});
}
}
}));
}
}

how to get data from api(Map type) for dropdown option

I have a problem when i want to get data from api and show them in dropdown option, I can print data when i run my code but in dropdown option i have below error :
type '(dynamic) => DropdownMenuItem' is not a subtype of type '(String, dynamic) => MapEntry' of 'transform'
import 'package:flutter/material.dart';
import 'package:dropdownfield/dropdownfield.dart';
import 'package:http/http.dart' as http;
import 'dart:async';`enter code here`
import 'dart:convert';
class InBoundRate extends StatefulWidget {
#override
_InBoundRateState createState() => _InBoundRateState();
}
class _InBoundRateState extends State<InBoundRate> {
#override
Widget build(BuildContext context) {
return Scaffold(
body: new Center(
child: new FutureBuilder(
future: GetInbound(),
builder: (BuildContext context, AsyncSnapshot<Map> snapshot) {
if (snapshot.hasData) {
Map content = snapshot.data ;
var sampleData = json.encode(content);
var json2 = JsonDecoder().convert(sampleData);
// print(json2['data']['countries']);
return DropdownButton(
items: json2.map(
(item) => DropdownMenuItem(
value: item['data']['countries'],
child: Text(item['data']['countries'])),
// onChanged: (Users value) {
// setState(() {
// _currentUser = value;
// });
// }
),
isExpanded: false,
//value: _currentUser,
hint: Text('Select User'),
);
} else {
return new Container();
}
}),
),
);
}
}
Future<Map> GetInbound() async {
String apiUrl = 'http://homaexpressco.ir/api/getRatesInformation2';
http.Response response = await http.get(apiUrl);
var res = json.decode(response.body);
return res;
}

Develop Reference

The Android operating system is a mobile operating system that was developed by Google (GOOGL?) to be primarily used for touchscreen devices, cell phones, and tablets.

how to pass array of data from API into graph in flutter? - android

Related

asynchronous suspension after adding ChangeNotifierProxyProvider to my MutiProviders

Error: Could not find the correct Provider<AuthState> above this AuthPage Widget

In FLutter trying to get JSON had this problem: [ LateInitializationError: Field '_userData#577066488' has not been initialized]

Unhandled Exception: type '_InternalLinkedHashMap<String, dynamic>' is not a subtype of type 'Iterable<dynamic>' why this error coming

how to get data from api(Map type) for dropdown option

Categories

Resources