I removed the first item which is added on catalog.dart . Logically if we see, it can be null so that we fetch data from network or json files. But after removing that first item. It shows an error. class CatalogModel { static List<Item> items; } Please review it once.

VxBuilder(
            mutations: {RemoveMutation},
            builder: (context) {
              return "\$${_cart.totalPrice}"
                  .text
                  .xl5
                  .color(context.theme.accentColor)
                  .make();
            },
)

)

error messege: The argument type 'Widget Function(BuildContext)' can't be assigned to the parameter type 'Widget Function(BuildContext, dynamic, VxStatus?)'.dartargument_type_not_assignable

I have already opened the original issues here on Flutter's official Github Issues page, but as I'm doing 30 Days of Flutter , I thought that I should share my issue here to.

Anyone can please check the original issue here - https://github.com/flutter/flutter/issues/82411

@iampawan @arps18

Hi, I wanna ask can we do like that the items which get added to the cart should still be visible in the cart after reopening the app with shared preferences ?

Encountered following bugs and applied undermentioned fixes

items were not initialized -> initialized as empty list static List<Item> items = List.empty(); required field missing in Item() constructor -> added required keyword Item({required this.id, ....}); Null safety found missing in copyWith() Item copyWith({ String? id ... In factory fromMap() the line which checks map nullability throwing error -> commented //if (map == null) return null; In home.dart list was not mapping to model -> distributed into two assignments List<Item> list = List.from(productsData) .map<Item>((item) => Item.fromMap(item)) .toList(); CatalogModel.items = list;

After clicking Login button the screen is changing even if the text and password fields are empty

import 'package:first_app/utils/approutes.dart';
import 'package:flutter/material.dart';

class Login extends StatefulWidget {
  @override
  _LoginState createState() => _LoginState();
}

class _LoginState extends State<Login> {
  String name = "";
  bool changebtn = false;
  final _formkey = GlobalKey<FormState>();

  movetohome(BuildContext context) async {
    if (_formkey.currentState!.validate()) {
      setState(() {
        changebtn = true;
      });
    }
    // push to move to next route

    await Future.delayed(Duration(seconds: 1));
    await Navigator.pushNamed(context, Approutes.homeRoute);
    setState(() {
      changebtn = false;
    });
  }

  @override
  Widget build(BuildContext context) {
    return Material(
        color: Colors.white,
        child: SingleChildScrollView(
          child: Form(
            key: _formkey,
            child: Column(
              children: [
                Image.asset(
                  "assets/images/top.png",
                  fit: BoxFit.cover,
                ),
                SizedBox(
                  height: 80.0,
                ),
                Text(
                  "Welcome $name",
                  style: TextStyle(fontWeight: FontWeight.bold, fontSize: 28),
                ),
                Padding(
                  padding: const EdgeInsets.symmetric(
                      vertical: 30.0, horizontal: 40.0),
                  child: Column(
                    children: [
                      TextFormField(
                        onChanged: (value) {
                          name = value;
                          setState(() {});
                        },
                        style: TextStyle(fontSize: 20),
                        decoration: InputDecoration(
                            hintText: "Enter username", labelText: "username"),
                        validator: (value) {
                          if (value!.isEmpty) {
                            return "Username cannot be empty";
                          }
                          return null;
                        },
                      ),
                      TextFormField(
                        style: TextStyle(fontSize: 20),
                        obscureText: true,
                        decoration: InputDecoration(
                            hintText: "Enter password", labelText: "password"),
                        validator: (value) {
                          if (value!.isEmpty) {
                            return "Password cannot be empty";
                          } else if (value.length < 6) {
                            return "Password length should be atleast 6";
                          }
                          return null;
                        },
                      ),
                      SizedBox(
                        height: 50.0,
                      ),
                      Material(
                        color: Colors.pinkAccent,
                        borderRadius: BorderRadius.circular(changebtn ? 60 : 8),
                        child: InkWell(
                          splashColor: Colors.yellow,
                          onTap: () => movetohome(context),
                          child: AnimatedContainer(
                            duration: Duration(seconds: 1),
                            width: changebtn ? 60 : 160,
                            height: 60,
                            // styling

                            alignment: Alignment.center,
                            child: changebtn
                                ? Icon(Icons.done)
                                : Text(
                                    "Login",
                                    style: TextStyle(
                                        fontSize: 25,
                                        color: Colors.white,
                                        fontWeight: FontWeight.bold),
                                  ),
                          ),
                        ),
                      ),
                    ],
                  ),
                ),
              ],
            ),
          ),
        ));
  }
}