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030Check ref.mounted after an await in a providerA provider can be disposed while a Future is pending. Check ref.mounted after the await before you touch state, or Riverpod 3 throws.State management
029Style an ElevatedButton with styleFrom and themesUse ElevatedButton.styleFrom for one button, ElevatedButtonThemeData for all of them, and WidgetStateProperty when a style depends on state.Widgets & layout
028Parse JSON safely with map patternsA switch on a map pattern checks keys and value types in one go, so bad JSON reaches your fallback case instead of a TypeError.Dart language
027Migrate a StateNotifier to a NotifierStateNotifier now lives in legacy.dart. Moving to Notifier takes a few mechanical steps, and one behaviour change is worth knowing about.State management
026Show real progress with a value on progress indicatorsGive CircularProgressIndicator or LinearProgressIndicator a value from 0.0 to 1.0 and they show how far along you are instead of spinning.Widgets & layout
025Initialise async dependencies in main() and use requireValueAwait a FutureProvider once before runApp, then read it synchronously everywhere with requireValue. No loading states for things that are always ready.State management
024firstOrNull instead of try/catch on StateErrorfirst, firstWhere and single throw when nothing matches. The OrNull versions return null, and the type system makes you handle it.Dart language
023Make text selectable across widgets with SelectionAreaWrap a subtree in SelectionArea and one selection runs across all its Text widgets. SelectionContainer.disabled carves out the parts to skip.Widgets & layout
022Pass arguments to a Notifier through its constructorIn Riverpod 3 a family notifier is a plain Notifier that takes its argument in the constructor, so every method can use it as a field.State management
021Skip nulls in collection literals with ...? and ?valueThe null-aware spread adds nothing for a null list, and a null-aware element leaves out a null entry, so you can drop the if (x != null).Dart language
020React to the app going to the background with AppLifecycleListenerAppLifecycleListener gives you one named callback per lifecycle transition. No observer mixin needed, but you must dispose it.Widgets & layout
019Extension types vs extension methodsAn extension method adds to a type. An extension type wraps it in a new static type, so a UserId can't be passed where an OrderId belongs.Dart language
018AsyncValue.guard instead of try/catch in notifiersAsyncValue.guard runs a Future and hands back AsyncData or AsyncError, so notifier methods need no try/catch.State management
017Replace Container with the widgets it wrapsContainer is a bundle of Padding, ColoredBox, DecoratedBox, Align and SizedBox. Use those directly and the whole subtree can be const.Widgets & layout
016Await several futures with a record's .waitFuture.wait gives you a List of Object. A record of futures with .wait keeps each type and tells you which one failed.Dart language
015Give buttons the same width with IntrinsicWidthWrap a Column in IntrinsicWidth and stretch its children, and every button matches the widest one, whatever the text size.Widgets & layout
014One widget for AsyncValue loading and error statesWrap AsyncValue in a small widget with a switch over AsyncData, AsyncError and AsyncLoading, and every async screen writes only its data UI.State management
013Destructure lists with list patternsList patterns pull values out of a list by position, and a rest element skips or collects whatever sits in the middle.Dart language
012Which Riverpod 3 provider should you use?Six providers cover almost every job in Riverpod 3. StateProvider, StateNotifierProvider and ChangeNotifierProvider now live in legacy.dart.State management
011Return SizedBox.shrink() when there is nothing to showA build method must return a widget. For "nothing", return const SizedBox.shrink(), not an empty Container.Widgets & layout
010Return multiple values with a recordA record returns two or more values without a throwaway class, and destructuring unpacks them in one line at the call site.Dart language
009ref.watch, ref.read or ref.listen?Watch to rebuild, read for a one-off value inside a callback, listen to run side effects like SnackBars.State management
008Switch on a record to match several values at oncePut two or three values in a record and switch on it. Each case is a row in a table, instead of a tangle of if/else.Dart language
007Use MediaQuery.sizeOf instead of MediaQuery.ofMediaQuery.of rebuilds your widget when anything changes. MediaQuery.sizeOf and friends rebuild only when the value you read changes.Widgets & layout
006The parts of a Riverpod 3 providerA provider is a global variable, a type, a body that gets a Ref, and optional modifiers. Here is what each part does.State management
005A Result type with a sealed classReturn success or failure instead of throwing, and let an exhaustive switch make sure every caller handles both.Dart language
004Check context.mounted after every awaitA BuildContext can go stale while you await. Check context.mounted before you use it again, or grab what you need first.Widgets & layout
003Getting a Future from a FutureProviderWatch provider.future to await one async provider inside another, and combine the results with plain async code.State management
002Column(spacing:) replaces a SizedBox between every childRow, Column and Flex take a spacing value, so you no longer need a SizedBox or the gap package between children.Widgets & layout
001Measure execution time with StopwatchDateTime.now() reads the wall clock, which can jump. Stopwatch can't, so use it to time code.Dart language