How to solve Non-nullable instance field 'catalog' must be initialized. Try adding an initializer expression,?

Question

I am getting an error Non-nullable instance field 'catalog' must be initialized. Try adding an initializer expression, or add a field initializer in this constructor, or mark it 'late'

import 'package:first_app/models/cart.dart';
import 'package:first_app/models/catalog.dart';
import 'package:velocity_x/velocity_x.dart';

class MyStore extends VxStore {
  CatelogModel catalog;
  CartModel cart;

  MyStore() {  #Getting error here#
    catalog = CatelogModel();
    cart = CartModel();
    cart.catalog = catalog;
  }
}

Solution

You need to initialize the properties CatelogModel catalog and CartModel cart or mark them as late. Right now its complaining that you have stated they should not be null but you've not initialize them in the constructor.

So you can either mark them as late

  class MyStore extends VxStore {
       late CatelogModel catalog;
       late CartModel cart;

       MyStore() {  #Getting error here#
          catalog = CatelogModel();
          cart = CartModel();
          cart.catalog = catalog;
       }
   }

or initialize them.

class MyStore extends VxStore {
  CatelogModel catalog;
  CartModel cart;

  MyStore()
      : catalog = CatelogModel(),
        cart = CartModel(){
          cart.catalog = catalog;
        }
}

Comments

[xion]

declare your catalog as nullable CatelogModel CatelogModel? catalog;

[Dinesh Gosavi]

Thanks the late keyword worked. but when i tried to initialize them it gave me error that The instance member 'catalog' can't be accessed in an initializer. Try replacing the reference to the instance member with a different expression.

[eyoeldefare]

Yeah, thats because its not a property. I will update the answer to express the new change.

[Admin]

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