The getter 'iterator' was called on null.

[heshesh2010]

Hi ,

i'm using mvc pattren here is snap of my code :

final PagingController<int, Restaurant> pagingNearRestaurantsController =
PagingController(firstPageKey: 0);

HomeController() {
pagingNearRestaurantsController.addPageRequestListener((pageKey) {
// _con.listenForOrders(pageKey);
// orderRepo.fetchPosts(orderRepo.nextUrl);
_fetchNearRestaurantsPage(pageKey);
});
}

Future _fetchNearRestaurantsPage(pageKey) async {

if(pageKey==0)
  newNearRestaurantsItems = await restaurantRepo.getNearRestaurants(deliveryAddress.value, deliveryAddress.value,null);
else
  newNearRestaurantsItems = await restaurantRepo.getNearRestaurants(deliveryAddress.value, deliveryAddress.value,restaurantRepo.nextUrl);

try{
  final isLastPage = newNearRestaurantsItems.length < _pageNearRestaurantsSize;
  if (isLastPage) {
    pagingNearRestaurantsController.appendLastPage(newNearRestaurantsItems);
  } else {
    final nextPageKey = pageKey + newNearRestaurantsItems.length;
    pagingNearRestaurantsController.appendPage(newNearRestaurantsItems, nextPageKey);
  }
} catch (error) {
  pagingNearRestaurantsController.error = error;
}

}

Future<List> getNearRestaurants(
Address myLocation, Address areaLocation,uri) async {

if(uri==null) {
uri = Helper.getUri('api/restaurants');
Map<String, dynamic> _queryParams = {};
SharedPreferences prefs = await SharedPreferences.getInstance();
Filter filter = Filter.fromJSON(
json.decode(
prefs.getString('filter') ?? new Filter("opened").toJson()));

if (!myLocation.isUnknown() && !areaLocation.isUnknown()) {
  _queryParams['myLon'] = myLocation.longitude.toString();
  _queryParams['myLat'] = myLocation.latitude.toString();
  _queryParams['areaLon'] = areaLocation.longitude.toString();
  _queryParams['areaLat'] = areaLocation.latitude.toString();
}
_queryParams['availability'] = filter.availability.toString();
uri = uri.replace(queryParameters: _queryParams);
uriFinal=uri;

}
else
uriFinal=uri;

http.Response response = await http.get(
    uriFinal );
var responseJson = json.decode(response.body);
var data = responseJson['data']['data'];

if (responseJson['data']['next_page_url'] != null) {
  nextUrl = responseJson['data']['next_page_url'];
}

return (data as List)
    .map((p) => Restaurant.fromJSON(p))
    .toList();

}

////
[VERBOSE-2:ui_dart_state.cc(177)] Unhandled Exception: NoSuchMethodError: The getter 'iterator' was called on null.
Receiver: null
Tried calling: iterator
#0 Object.noSuchMethod (dart:core-patch/object_patch.dart:51:5)
#1 new List.from (dart:core-patch/array_patch.dart:57:19)
#2 PagingController.notifyStatusListeners (package:infinite_scroll_pagination/src/core/paging_controller.dart:134:28)
#3 PagingController.value= (package:infinite_scroll_pagination/src/core/paging_controller.dart:175:7)
#4 PagingController.error= (package:infinite_scroll_pagination/src/core/paging_controller.dart:59:5)
#5 HomeController._fetchNearRestaurantsPage (package:foodlobby_client_app/src/controllers/home_controller.dart:72:39)

#6 new HomeController. (package:foodlobby_client_app/src/controllers/home_controller.dart:40:7)
#7 PagingController.notifyPageRequestListeners. (package:infinite_scroll_pagination/src/core/paging<…

[EdsonBueno]

Hi @heshesh2010.
Your problem is the same as the one of this issue.
Try using the same solution I provided there. If you face any problems implementing it, or if it doesn't work, please contact me on the chat and I'll be glad to help you.