Error provider

lib/providers/main.dart

@@ -8,10 +8,17 @@ class GymLinkProvider with ChangeNotifier {
   bool get blackTheme => _blackTheme;
   ThemeData _theme = myTheme;
   ThemeData get theme => _theme;
+  void Function() _onError = () => {};
+
+  void Function() get onError => _onError;
+
   void onTokenReceived(String token) {
     if (token == 'token123') {
       _isLoading = false;
       notifyListeners();
+    } else {
+      _isLoading = true;
+      notifyListeners();
     }
   }
 
@@ -25,4 +32,8 @@ class GymLinkProvider with ChangeNotifier {
     _theme = theme;
     notifyListeners();
   }
+
+  void setOnError(void Function() onError) {
+    _onError = onError;
+  }
 }