A library that solves the problem of Riverpod's Ref.watch() not supporting deep-equals for Iterables and Maps. It prevents unnecessary re-renders caused by reference comparison when watching collections (List, Map, Set) and enables efficient state management.

Features

• Deep Equals Support: Efficient state watching with deep comparison for List, Map, and Set
• Prevent Unnecessary Re-renders: Avoids re-rendering when collection contents are the same
• Extension Functions: Easy usage through Ref.watchBy() and WidgetRef.watchBy()

Getting started

Add the following dependency to your pubspec.yaml:

dependencies:
  flutter_riverpod_watch_plus: ^1.0.0

Usage

import 'package:flutter_riverpod/flutter_riverpod.dart';
import 'package:flutter_riverpod_watch_plus/flutter_riverpod_watch_plus.dart';

// Provider watching a regular List
final listProvider = StateProvider<List<String>>((ref) => ['a', 'b', 'c']);

// Traditional watching method (unnecessary re-renders due to reference comparison)
final badExample = Provider((ref) {
  final list = ref.watch(listProvider); // Re-renders even when content is the same
  return list.length;
});

// Using watchBy() for efficient watching (Deep Equals)
final goodExample = Provider((ref) {
  final list = ref.watchBy(listProvider, (value) => value); // No re-render when content is the same
  return list.length;
});

// Usage example in Widget
class MyWidget extends ConsumerWidget {
  @override
  Widget build(BuildContext context, WidgetRef ref) {
    // watchBy() can also be used with WidgetRef
    final filteredList = ref.watchBy(
      listProvider,
      (list) => list.where((item) => item.startsWith('a')).toList(),
    );

    return ListView.builder(
      itemCount: filteredList.length,
      itemBuilder: (context, index) {
        return ListTile(title: Text(filteredList[index]));
      },
    );
  }
}

Additional information

This package extends Riverpod's Ref.watch() functionality to provide deep-equals support for collections. It uses an intermediate object (WatchValue) to perform content comparison of collections and prevent unnecessary re-renders. Bug reports and feature requests are accepted on GitHub.