Unable to create getter in Changenotifier class. error when using Provider in Flutter

Issue

hello i am new with provider. i wrote steps here where i have problem.
1- i called api after that i have data in my Model class.
2- then in ChangeNotifer class i want to make getter of list which is in Model class object.
i am unable to add model class response data to this getter variable.

class CartProductNotifier with ChangeNotifier{

final _webServices = WebServices();
GetProductDetailsModel _getProductDetailsModel;
List<Vd> _vdList = [];

callApi(String handle) {
    return _webServices.getProductDetails(handle).then((value) {
      _getProductDetailsModel = value;
      _vdList = value.data.product.vd; // after api call done data is in _vdList
      return value;
    });
  }

}

now i am creating getter

List<Vd> get vdata {
   return _vdList;
 }

but when i called this getter from my ProductDetailsScreen class i am getting blank array or null.

 Consumer<CartProductListNotifier>(
                  builder: (context, value, child) {
                    return Text(
                       value.vdata[index].quantitySelectedByUser.toString(),  //data is not coming here
                    style: TextStyle(
                    fontSize: kFontSize16, fontWeight: kMediumFontWeight, color: Colors.black),
                    );
                  },
                ),

now i am unable to update value in Text widget which is in Consumer notifier.

this is my main.dart

MultiProvider(
      providers: [
        ChangeNotifierProvider(
          create: (context) => CartProductListNotifier(),
        ),
      ],
      child: MaterialApp(
        title: 'Application',
        debugShowCheckedModeBanner: false,

please solve this issue or told me another good way to Call Api with Model class with Provider.
Thanks in Advance.

Solution

call setData function after calling API is solved my problem now i am getting result in _vdList.

example

setData(GetProductDetailsModel _productModel) {
   _getProductDetailsModel = _productModel;
   _vdList = _productModel.data.product.vd;
   _voList = _productModel.data.product.vo;
   notifyListeners();
 }

Answered By – Sachin Kumar Rajput

Answer Checked By – Senaida (FlutterFixes Volunteer)