The getter 'totalCartPrice' was called on null. Receiver: null Tried calling: totalCartPrice - flutter

Question

The app itself works well. The product is added to the cart, but when you go to the cart page, this error appears. Maybe someone came across. I looked at similar errors, but my solution did not help.
The getter 'totalCartPrice' was called on null. Receiver: null Tried calling: totalCartPrice
enter code here
import 'package:flutter/material.dart';
import 'package:food_course/scr/helpers/order.dart';
import 'package:food_course/scr/helpers/style.dart';
import 'package:food_course/scr/models/cart_item.dart';
import 'package:food_course/scr/models/products.dart';
import 'package:food_course/scr/providers/app.dart';
import 'package:food_course/scr/providers/user.dart';
import 'package:food_course/scr/widgets/custom_text.dart';
import 'package:food_course/scr/widgets/loading.dart';
import 'package:provider/provider.dart';
import 'package:uuid/uuid.dart';
class CartScreen extends StatefulWidget {
#override
_CartScreenState createState() => _CartScreenState();
}
class _CartScreenState extends State<CartScreen> {
final _key = GlobalKey<ScaffoldState>();
OrderServices _orderServices = OrderServices();
#override
Widget build(BuildContext context) {
final user = Provider.of<UserProvider>(context);
final app = Provider.of<AppProvider>(context);
return Scaffold(
key: _key,
appBar: AppBar(
iconTheme: IconThemeData(color: black),
backgroundColor: white,
elevation: 0.0,
title: CustomText(text: "Shopping Cart"),
leading: IconButton(
icon: Icon(Icons.close),
onPressed: () {
Navigator.pop(context);
}),
),
backgroundColor: white,
body: app.isLoading ? Loading() : ListView.builder(
itemCount: user.userModel.cart.length,
itemBuilder: (_, index) {
return Padding(
padding: const EdgeInsets.all(16),
child: Container(
height: 120,
decoration: BoxDecoration(
borderRadius: BorderRadius.circular(20),
color: white,
boxShadow: [
BoxShadow(
color: red.withOpacity(0.2),
offset: Offset(3, 2),
blurRadius: 30)
]),
child: Row(
children: <Widget>[
ClipRRect(
borderRadius: BorderRadius.only(
bottomLeft: Radius.circular(20),
topLeft: Radius.circular(20),
),
child: Image.network(
user.userModel.cart[index].image,
height: 120,
width: 140,
fit: BoxFit.fill,
),
),
SizedBox(
width: 10,
),
Expanded(
child: Row(
mainAxisAlignment: MainAxisAlignment.spaceBetween,
children: <Widget>[
RichText(
text: TextSpan(children: [
TextSpan(
text: user.userModel.cart[index].name+ "\n",
style: TextStyle(
color: black,
fontSize: 20,
fontWeight: FontWeight.bold)),
TextSpan(
text: "\$${user.userModel.cart[index].price / 100} \n\n",
style: TextStyle(
color: black,
fontSize: 18,
fontWeight: FontWeight.w300)),
TextSpan(
text: "Quantity: ",
style: TextStyle(
color: grey,
fontSize: 16,
fontWeight: FontWeight.w400)),
TextSpan(
text: user.userModel.cart[index].quantity.toString(),
style: TextStyle(
color: primary,
fontSize: 16,
fontWeight: FontWeight.w400)),
]),
),
IconButton(
icon: Icon(
Icons.delete,
color: red,
),
onPressed: ()async{
app.changeLoading();
bool value = await user.removeFromCart(cartItem: user.userModel.cart[index]);
if(value){
user.reloadUserModel();
print("Item added to cart");
_key.currentState.showSnackBar(
SnackBar(content: Text("Removed from Cart!"))
);
app.changeLoading();
return;
}else{
print("ITEM WAS NOT REMOVED");
app.changeLoading();
}
})
],
),
)
],
),
),
);
}),
bottomNavigationBar: Container(
height: 70,
child: Padding(
padding: const EdgeInsets.all(8.0),
child: Row(
mainAxisAlignment: MainAxisAlignment.spaceBetween,
children: <Widget>[
RichText(
text: TextSpan(children: [
TextSpan(
text: "Total: ",
style: TextStyle(
color: grey,
fontSize: 22,
fontWeight: FontWeight.w400)),
TextSpan(
text: " \$${user.userModel.totalCartPrice / 100}",
style: TextStyle(
color: primary,
fontSize: 22,
fontWeight: FontWeight.normal)),
]),
),
Container(
decoration: BoxDecoration(
borderRadius: BorderRadius.circular(20), color: primary),
child: FlatButton(
onPressed: () {
if(user.userModel.totalCartPrice == 0){
showDialog(
context: context,
builder: (BuildContext context) {
return Dialog(
shape: RoundedRectangleBorder(
borderRadius:
BorderRadius.circular(20.0)), //this right here
child: Container(
height: 200,
child: Padding(
padding: const EdgeInsets.all(12.0),
child: Column(
mainAxisAlignment: MainAxisAlignment.center,
crossAxisAlignment: CrossAxisAlignment.start,
children: [
Row(
mainAxisAlignment: MainAxisAlignment.center,
children: <Widget>[
Text('Your cart is emty', textAlign: TextAlign.center,),
],
),
],
),
),
),
);
});
return;
}
showDialog(
context: context,
builder: (BuildContext context) {
return Dialog(
shape: RoundedRectangleBorder(
borderRadius:
BorderRadius.circular(20.0)), //this right here
child: Container(
height: 200,
child: Padding(
padding: const EdgeInsets.all(12.0),
child: Column(
mainAxisAlignment: MainAxisAlignment.center,
crossAxisAlignment: CrossAxisAlignment.start,
children: [
Text('You will be charged \$${user.userModel.totalCartPrice / 100} upon delivery!', textAlign: TextAlign.center,),
SizedBox(
width: 320.0,
child: RaisedButton(
onPressed: () async{
var uuid = Uuid();
String id = uuid.v4();
_orderServices.createOrder(
userId: user.user.uid,
id: id,
description: "Some random description",
status: "complete",
totalPrice: user.userModel.totalCartPrice,
cart: user.userModel.cart
);
for(CartItemModel cartItem in user.userModel.cart){
bool value = await user.removeFromCart(cartItem: cartItem);
if(value){
user.reloadUserModel();
print("Item added to cart");
_key.currentState.showSnackBar(
SnackBar(content: Text("Removed from Cart!"))
);
}else{
print("ITEM WAS NOT REMOVED");
}
}
_key.currentState.showSnackBar(
SnackBar(content: Text("Order created!"))
);
Navigator.pop(context);
},
child: Text(
"Accept",
style: TextStyle(color: Colors.white),
),
color: const Color(0xFF1BC0C5),
),
),
SizedBox(
width: 320.0,
child: RaisedButton(
onPressed: () {
Navigator.pop(context);
},
child: Text(
"Reject",
style: TextStyle(color: Colors.white),
),
color: red
),
)
],
),
),
),
);
});
},
child: CustomText(
text: "Check out",
size: 20,
color: white,
weight: FontWeight.normal,
)),
)
],
),
),
),
);
}
}
USER.dart
import 'dart:async';
import 'package:cloud_firestore/cloud_firestore.dart';
import 'package:flutter/material.dart';
import 'package:flutter/widgets.dart';
import 'package:firebase_auth/firebase_auth.dart';
import 'package:food_course/scr/helpers/order.dart';
import 'package:food_course/scr/helpers/user.dart';
import 'package:food_course/scr/models/cart_item.dart';
import 'package:food_course/scr/models/order.dart';
import 'package:food_course/scr/models/products.dart';
import 'package:food_course/scr/models/user.dart';
import 'package:uuid/uuid.dart';
enum Status{Uninitialized, Authenticated, Authenticating, Unauthenticated}
class UserProvider with ChangeNotifier{
FirebaseAuth _auth;
FirebaseUser _user;
Status _status = Status.Uninitialized;
Firestore _firestore = Firestore.instance;
UserServices _userServicse = UserServices();
OrderServices _orderServices = OrderServices();
UserModel _userModel;
// getter
UserModel get userModel => _userModel;
Status get status => _status;
FirebaseUser get user => _user;
// public variables
List<OrderModel> orders = [];
final formkey = GlobalKey<FormState>();
TextEditingController email = TextEditingController();
TextEditingController password = TextEditingController();
TextEditingController name = TextEditingController();
UserProvider.initialize(): _auth = FirebaseAuth.instance{
_auth.onAuthStateChanged.listen(_onStateChanged);
}
Future<bool> signIn()async{
try{
_status = Status.Authenticating;
notifyListeners();
await _auth.signInWithEmailAndPassword(email: email.text.trim(), password: password.text.trim());
return true;
}catch(e){
_status = Status.Unauthenticated;
notifyListeners();
print(e.toString());
return false;
}
}
Future<bool> signUp()async{
try{
_status = Status.Authenticating;
notifyListeners();
await _auth.createUserWithEmailAndPassword(email: email.text.trim(), password: password.text.trim()).then((result){
_firestore.collection('users').document(result.user.uid).setData({
'name':name.text,
'email':email.text,
'uid':result.user.uid,
"likedFood": [],
"likedRestaurants": []
});
});
return true;
}catch(e){
_status = Status.Unauthenticated;
notifyListeners();
print(e.toString());
return false;
}
}
Future signOut()async{
_auth.signOut();
_status = Status.Unauthenticated;
notifyListeners();
return Future.delayed(Duration.zero);
}
void clearController(){
name.text = "";
password.text = "";
email.text = "";
}
Future<void> reloadUserModel()async{
_userModel = await _userServicse.getUserById(user.uid);
notifyListeners();
}
Future<void> _onStateChanged(FirebaseUser firebaseUser) async{
if(firebaseUser == null){
_status = Status.Unauthenticated;
}else{
_user = firebaseUser;
_status = Status.Authenticated;
_userModel = await _userServicse.getUserById(user.uid);
}
notifyListeners();
}
Future<bool> addToCard({ProductModel product, int quantity})async{
print("THE PRODUC IS: ${product.toString()}");
print("THE qty IS: ${quantity.toString()}");
try{
var uuid = Uuid();
String cartItemId = uuid.v4();
List cart = _userModel.cart;
// bool itemExists = false;
Map cartItem ={
"id": cartItemId,
"name": product.name,
"image": product.image,
"restaurantId": product.restaurantId,
"totalRestaurantSale": product.price * quantity,
"productId": product.id,
"price": product.price,
"quantity": quantity
};
CartItemModel item = CartItemModel.fromMap(cartItem);
// if(!itemExists){
print("CART ITEMS ARE: ${cart.toString()}");
_userServicse.addToCart(userId: _user.uid, cartItem: item);
// }
return true;
}catch(e){
print("THE ERROR ${e.toString()}");
return false;
}
}
getOrders()async{
orders = await _orderServices.getUserOrders(userId: _user.uid);
notifyListeners();
}
Future<bool> removeFromCart({CartItemModel cartItem})async{
print("THE PRODUC IS: ${cartItem.toString()}");
try{
_userServicse.removeFromCart(userId: _user.uid, cartItem: cartItem);
return true;
}catch(e){
print("THE ERROR ${e.toString()}");
return false;
}
}
}
main.dart
import 'package:flutter/material.dart';
import 'package:food_course/scr/providers/app.dart';
import 'package:food_course/scr/providers/category.dart';
import 'package:food_course/scr/providers/product.dart';
import 'package:food_course/scr/providers/restaurant.dart';
import 'package:food_course/scr/providers/user.dart';
import 'package:food_course/scr/screens/home.dart';
import 'package:food_course/scr/screens/login.dart';
import 'package:food_course/scr/screens/splash.dart';
import 'package:food_course/scr/widgets/loading.dart';
import 'package:provider/provider.dart';
void main() {
WidgetsFlutterBinding.ensureInitialized();
runApp(MultiProvider(
providers: [
ChangeNotifierProvider.value(value: AppProvider()),
ChangeNotifierProvider.value(value: UserProvider.initialize()),
ChangeNotifierProvider.value(value: CategoryProvider.initialize()),
ChangeNotifierProvider.value(value: RestaurantProvider.initialize()),
ChangeNotifierProvider.value(value: ProductProvider.initialize()),
],
child: MaterialApp(
debugShowCheckedModeBanner: false,
title: 'Food App',
theme: ThemeData(
primarySwatch: Colors.red,
),
home: ScreensController())));
}
class ScreensController extends StatelessWidget {
#override
Widget build(BuildContext context) {
final auth = Provider.of<UserProvider>(context);
switch (auth.status) {
case Status.Uninitialized:
return Splash();
case Status.Unauthenticated:
case Status.Authenticating:
return LoginScreen();
case Status.Authenticated:
return Home();
default:
return LoginScreen();
}
}
}