Flutter：从小部件树外部访问提供者

Question

In my Flutter app I have to update the state hold by a Provider as soon as a push notification arrives so that the UI can be rebuilt. The PushNotifications service is a class (not a widget) like that:

class PushNotifications {
  ...

  Future<void> init() async {    
    _firebaseMessaging.configure(onMessage: (Map<String, dynamic> data) {
      // here I receive the data from the notification that I have to add to the provider

    });
  }
}

And this is my simple provider:

class NewsProvider with ChangeNotifier {
  List<News> _news;
  get news => _news;

  NewsProvider();

  void addNews(News news) {
    _news.add(news);
    notifyListeners();
  }
}

I can't come up with how I can achive that since the PushNotifications class doesn't have a context.

Answer 1

Please check out Riverpod which is basically Provider without its limitation. Riverpod is very similar to Provider and also created by the same author Remi Rousselet.

According to the author :

Riverpod project can be considered as a rewrite of provider to make improvements that would be otherwise impossible.

Official website of Riverpod : https://riverpod.dev/

Riverpod on Pub.dev : https://pub.dev/packages/riverpod