flutter_piper #

Flutter widgets for Piper state management.

Installation #

dependencies:
  piper: ^0.0.1
  flutter_piper: ^0.0.1

Widgets #

ViewModelScope #

Provides multiple ViewModels to the widget tree:

ViewModelScope(
  create: [
    () => AuthViewModel(authRepo),
    () => TodosViewModel(todoRepo),
  ],
  child: MyApp(),
)

// Access anywhere below:
final vm = context.vm<AuthViewModel>();

Scoped<T> #

Scopes a single typed ViewModel with a builder pattern:

Scoped<DetailViewModel>(
  create: () => DetailViewModel(id),
  builder: (context, vm) => DetailPage(),
)

// Access via context:
final vm = context.vm<DetailViewModel>();
// Or use the semantic alias:
final vm = context.scoped<DetailViewModel>();

Named Scopes #

Share ViewModels across multiple routes with named scopes:

ViewModelScope.named(
  name: 'checkout',
  create: [() => CheckoutViewModel()],
  child: CheckoutFlow(),
)

// Access by name from any descendant:
final vm = context.vm<CheckoutViewModel>(scope: 'checkout');

StateBuilder #

Rebuilds when state changes:

vm.count.build((count) => Text('$count'))

StateListener #

Side effects without rebuilding:

vm.isDeleted.listen(
  onChange: (prev, curr) {
    if (curr) Navigator.of(context).pop();
  },
  child: // your UI
)

StateEffect #

Post-frame side effects with conditions:

StateEffect<bool>(
  listenable: vm.isLoggedIn.listenable,
  when: (prev, curr) => !prev && curr,
  effect: (_, ctx) => Navigator.of(ctx).pushReplacement(...),
  child: // your UI
)

Learn More #

• Piper Documentation
• Examples