14b9a8c4c4
* Material text theme updates & flutter pub upgrade (#411) * Beta channel updates (#412) * fix deprecated usages in provider_shopper - beta channel * fix deprecated usages in animations - beta channel * fix deprecated usages in provider_counter - beta * Updates additional samples for beta release (#416) * use headline6 instead of title * fix another title -> headline6 Co-authored-by: Brett Morgan <brett.morgan@gmail.com> Co-authored-by: Andrew Brogdon <RedBrogdon@users.noreply.github.com>
provider_shopper
A Flutter sample app that shows a state management approach using the Provider package. This is the app discussed in the Simple app state management section of flutter.dev.
Goals for this sample
- Show simple use of
Providerfor providing an immutable value to a subtree - Illustrate a simple state management approach using the ChangeNotifier class
- Show use of
ProxyProviderfor provided objects that depend on other provided objects
The important bits
lib/main.dart
Here the app sets up objects it needs to track state: a catalog and a shopping cart. It builds
a MultiProvider to provide both objects at once to widgets further down the tree.
The CartModel instance is provided using a ChangeNotifierProxyProvider, which combines
two types of functionality:
- It will automatically subscribe to changes in
CartModel(if you only want this functionality simply useChangeNotifierProvider). - It takes the value of a previously provided object (in this case,
CatalogModel, provided just above), and uses it to build the value ofCartModel(if you only want this functionality, simply useProxyProvider).
lib/models/*
This directory contains the model classes that are provided in main.dart. These classes
represent the app state.
lib/screens/*
This directory contains widgets used to construct the two screens of the app: the catalog and
the cart. These widgets have access to the current state of both the catalog and the cart
via Provider.of.
Questions/issues
If you have a general question about Provider, the best places to go are:
If you run into an issue with the sample itself, please file an issue in the main Flutter repo.