^0.13.0 to ^0.14.0

With the release of version 0.14.0 of Riverpod, the syntax for using StateNotifierProvider changed (see https://github.com/rrousselGit/riverpod/issues/341 for the explanation).

For the entire article, consider the following StateNotifier:

class MyModel {}

class MyStateNotifier extends StateNotifier<MyModel> {
  MyStateNotifier(): super(MyModel());
}

The changes

• StateNotifierProvider takes an extra generic parameter, which should be the type of the state of your StateNotifier.

  Before:

  final provider = StateNotifierProvider<MyStateNotifier>((ref) {
    return MyStateNotifier();
  });

  After:

  final provider = StateNotifierProvider<MyStateNotifier, MyModel>((ref) {
    return MyStateNotifier();
  });

• to obtain the StateNotifier, you should now read myProvider.notifier instead of just myProvider:

  Before:

  Widget build(BuildContext context, ScopedReader watch) {
    MyStateNotifier notifier = watch(provider);
  }

  After:

  Widget build(BuildContext context, ScopedReader watch) {
    MyStateNotifier notifier = watch(provider.notifier);
  }

• to listen to the state of the StateNotifier, you should now read myProvider instead of myProvider.state:

  Before:

  Widget build(BuildContext context, ScopedReader watch) {
    MyModel state = watch(provider.state);
  }

  After:

  Widget build(BuildContext context, ScopedReader watch) {
    MyModel state = watch(provider);
  }

Using the migration tool to automatically upgrade your projects to the new syntax

With version 0.14.0 came the release of a command line tool for Riverpod, which can help you migrate your projects.

Installing the command line

To install the migration tool, run:

dart pub global activate riverpod_cli

You should now be able to run:

riverpod --help

Usage

Now that the command line is installed, we can start using it.

• First, open the project you want to migrate in your terminal.
• Do not upgrade Riverpod.
  The migration tool will upgrade the version of Riverpod for you.
• Make sure that your project does not contain errors.
• Execute:

  riverpod migrate

The tool will then analyze your project and suggest changes. For example you may see:

Widget build(BuildContext context, ScopedReader watch) {
-  MyModel state = watch(provider.state);
+  MyModel state = watch(provider);
}

Accept change (y = yes, n = no [default], A = yes to all, q = quit)? 

To accept the change, simply press y. Otherwise to reject it, press n.