CODEWITHSUNDEEP
flutterdartprovider
Axel
Axel

Reputation: 5111

Using provider in ancestor

I am using provider package to manage state in Flutter.

This is main.dart:

class _MyAppState extends State<MyApp> {
  @override
  Widget build(BuildContext context) {
    return ChangeNotifierProvider<Application>(
      builder: (_) => Application(),
      child: MaterialApp(
        debugShowCheckedModeBanner: false,
        home: HomeScreen(),
        initialRoute: AppRoutes.home
      ),
    );
  }
}

Now, how can I use the application provider in main.dart? I tried doing final app = Provider.of<Application>(context).app; in build function. However, it throws the following error:

Error: Could not find the correct Provider<Application> above this MyApp Widget

To fix, please:

  * Ensure the Provider<Application> is an ancestor to this MyApp Widget
  * Provide types to Provider<Application>
  * Provide types to Consumer<Application>
  * Provide types to Provider.of<Application>()
  * Always use package imports. Ex: `import 'package:my_app/my_code.dart';
  * Ensure the correct `context` is being used.

I know that the provider can be accessed by the children but is there any way to access in ancestor/main.dart as well? I need to manage an app wide state.

Upvotes: 2

Views: 2289

Answers (1)

R&#233;mi Rousselet
R&#233;mi Rousselet

Reputation: 276911

That's what Consumer is here for.

You can use it to do:

Widget build(BuildContext context) {
  return Provider<Whatever>(
    builder: (_) => Whatever(),
    child: Consumer<Whatever>(
      builder: (_, whatever, __) {
        // todo: use `whatever`
      },
    ),
  );
}

Upvotes: 2

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