Managing State in Flutter

Sep 22 2022 · Dart 2.17, Flutter 3.0, Android Studio Chipmunk

Part 1: Understand State Management

06. Extend a Value Notifier

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Previous episode: 05. Add a Value Notifier Next episode: 07. Meet the Inherited Widget

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When we last left, we defined a value notifier to let us know when to update our state. The value notifier was so closely related to our model object, a better solution would be to just have our model extend the value notifier. Let’s do this now.

class Pillar extends ValueNotifier<int> {
Pillar({required this.type, int articleCount = 10}) : super(articleCount);
class Pillar extends ValueNotifier<int> {
  int get articleCount => value;
  var active = true;
  final PillarType type;
void increaseArticleCount({int by = 1}) {
    value += by;
void initState() {
    pillarData.addListener(() {
        setState(() {});
void dispose() {
body: TutorialsPage(pillar: pillarData),
const TutorialsPage({required this.pillar, super.key});
child: TutorialWidget(pillar: widget.pillar),
const TutorialWidget({required this.pillar, super.key});
widget.pillar.increaseArticleCount(by: 1);
    valueListenable: pillarData,
    builder: (context, value, child) {
        return TutorialsPage(pillar: pillarData);