task: introducing provider for cart and order

Author: Atuoha

lib/main.dart

@@ -1,9 +1,10 @@
 import 'dart:async';
-import 'package:cloud_firestore/cloud_firestore.dart';
-import 'package:firebase_auth/firebase_auth.dart';
 import 'package:firebase_core/firebase_core.dart';
 import 'package:flutter/material.dart';
+import 'package:multivendor_shop/providers/cart.dart';
+import 'package:multivendor_shop/providers/order.dart';
 import 'package:multivendor_shop/views/splash/entry.dart';
+import 'package:provider/provider.dart';
 import 'constants/colors.dart';
 import 'routes/routes.dart';
 import 'firebase_options.dart';
@@ -35,7 +36,17 @@ class _MultiVendorState extends State<MultiVendor> {
         primaryColor: primaryColor,
       ),
       debugShowCheckedModeBanner: false,
-      home: const EntryScreen(),
+      home: MultiProvider(
+        providers: [
+          ChangeNotifierProvider(
+            create: (context) => CartData(),
+          ),
+          ChangeNotifierProvider(
+            create: (context) => OrderData(),
+          ),
+        ],
+        child: const EntryScreen(),
+      ),
       routes: routes,
     );
   }

lib/models/cart.dart

@@ -0,0 +1,29 @@
+class CartItem {
+  final String id;
+  final String prodId;
+  final String prodName;
+  final String prodImgUrl;
+  double prodPrice;
+  double totalPrice;
+  int quantity;
+
+  CartItem({
+    required this.id,
+    required this.prodId,
+    required this.prodName,
+    required this.prodPrice,
+    required this.prodImgUrl,
+    this.quantity = 1,
+    required this.totalPrice,
+  });
+
+  incrementQuantity() {
+    quantity += 1;
+    totalPrice += prodPrice;
+  }
+
+  decrementQuantity() {
+    quantity -= 1;
+    totalPrice -= prodPrice;
+  }
+}

lib/models/order.dart

@@ -0,0 +1,15 @@
+class Order {
+  final String id;
+  final String prodId;
+  final String prodName;
+  final String prodImg;
+  final int quantity;
+
+  Order({
+    required this.id,
+    required this.prodId,
+    required this.prodName,
+    required this.prodImg,
+    required this.quantity,
+  });
+}

lib/providers/cart.dart

@@ -0,0 +1,40 @@
+import 'package:flutter/material.dart';
+
+class CartData extends ChangeNotifier {
+  var totalPrice = 0.0;
+
+  void incrementProductQuantity(String id) {
+    var cartItem = _cartItems.firstWhere((item) => item.id == id);
+    cartItem.incrementQuantity();
+    notifyListeners();
+  }
+
+  void decrementProductQuantity(String id) {
+    var cartItem = _cartItems.firstWhere((item) => item.id == id);
+    cartItem.decrementQuantity();
+    notifyListeners();
+  }
+
+  void removeFromCart(String id) {
+    var cartItem = _cartItems.firstWhere((item) => item.id == id);
+    _cartItems.remove(cartItem);
+    notifyListeners();
+  }
+
+  get cartItemCount {
+    return _cartItems.length;
+  }
+
+  get cartTotalPrice {
+    for (var item in _cartItems) {
+      totalPrice += item.totalPrice;
+    }
+    return totalPrice;
+  }
+
+  get cartItems {
+    return [..._cartItems];
+  }
+
+  final _cartItems = [];
+}

lib/providers/order.dart

@@ -0,0 +1,28 @@
+import 'package:flutter/material.dart';
+
+class OrderData extends ChangeNotifier {
+  var totalPrice = 0.0;
+
+  void removeFromOrder(String id) {
+    var orderItem = _orderItems.firstWhere((item) => item.id == id);
+    _orderItems.remove(orderItem);
+    notifyListeners();
+  }
+
+  get orderItemCount {
+    return _orderItems.length;
+  }
+
+  get orderItems {
+    return [..._orderItems];
+  }
+
+  get orderTotalPrice {
+    for (var item in _orderItems) {
+      totalPrice += item.totalPrice;
+    }
+    return totalPrice;
+  }
+
+  final _orderItems = [];
+}

pubspec.lock

@@ -507,7 +507,7 @@ packages:
     source: hosted
     version: "4.2.4"
   provider:
-    dependency: transitive
+    dependency: "direct main"
     description:
       name: provider
       url: "https://pub.dartlang.org"

pubspec.yaml

@@ -52,6 +52,7 @@ dependencies:
   badges: ^2.0.3
   floating_action_bubble: ^1.1.4
   font_awesome_flutter: ^10.2.1
+  provider: ^6.0.3
 
 dev_dependencies:
   flutter_test: