Provider does not update a variable while fetching data - flutter

Question

Firstly, I have a login screen and I want to change button with CircularProgressIndicator when button is clicked. I am using Provider to handle state management. Here is my Provider class.
class UserProvider with ChangeNotifier {
bool _loading = false;
bool get loading => _loading;
UserViewModel? user;
bool isLoggedOut = false;
TokenRequestModel tokenRequestModel = TokenRequestModel(
username: '', password: '', environment: '', deviceToken: '');
login(TokenRequestModel requestModel) async {
_loading = true;
user = await UserService().login(requestModel);
_loading = false;
notifyListeners();
}
}
I change loading value between my Api call. Then I want to catch it in my login screen to change widget. With that way I prevent button clicked multiple times and my login screen looks like this.
Column(
children: [
//textfield widgets
context.watch<UserProvider>().loading == false
? button(context, userProvider)
: Container(
height: 35.h,
width: 280.w,
decoration: BoxDecoration(color: blueLogo),
child: const CircularProgressIndicator(
color: Colors.white,
),
)
],
),
I have tried multiple methods like Consumer, userProvider = Provider.of<UserProvider>(context); but nothing happens. What am I missing or what is the mistake of my method to handle state management? Would you help me to find right way to do? Thanks

Answer 1

Seems to me that you are notifying listeners when _loading has gone back to being false again, but you never notified them when it turned true!
Try this, in your provider file:
class UserProvider extends ChangeNotifier {
bool _loading = false;
bool get loading => _loading;
UserViewModel? user;
bool isLoggedOut = false;
TokenRequestModel tokenRequestModel = TokenRequestModel(
username: '', password: '', environment: '', deviceToken: '');
login(TokenRequestModel requestModel) async {
_loading = true;
notifyListeners(); // <- The crucial line, right here!
user = await UserService().login(requestModel);
_loading = false;
notifyListeners();
}
}
I noticed you had used with ChangeNotifier instead of extends ChangeNotifier... but I don't know what that does! I always use extends ChangeNotifier and that works for me.