ChangeNotifier Explained | Flutter for Web Developers

What’s ChangeNotifier?

The ChangeNotifier class is a mixin in Flutter that provides a change notification API. It allows classes to notify listeners when changes occur. Important methods include addListener, removeListener, and notifyListeners, which manage listener registration and notification.

Check the official documentation for more.

ChangeNotifier explained for Web Developers

From a Web Developer’s perspective, ChangeNotifier is similar to state management solutions in frameworks like React (useState/useEffect), Angular (Services), and Vue (Vuex). It allows for reactive programming by notifying UI components when the underlying data changes, ensuring that only the necessary parts of the UI are updated.

Example Code

Here is an example of how to use ChangeNotifier:

class Counter extends ChangeNotifier {
  int _count = 0;

  int get count => _count;

  void increment() {
    _count++;
    notifyListeners();
  }
}

void main() {
  final counter = Counter();
  counter.addListener(() {
    print('Count: ${counter.count}');
  });
  counter.increment(); // Output: Count: 1
}

ChangeNotifier Remarks

ChangeNotifier is a powerful tool for state management in Flutter, allowing developers to create responsive applications that efficiently update the UI based on data changes.