lindi 0.1.0

Lindi is a lightweight and reactive state management library for Flutter that simplifies building applications with dynamic UI updates.

example/lib/main.dart

import 'package:flutter/material.dart';
import 'package:lindi/lindi.dart';

void main() {
  // Register the LindiViewModels globally
  LindiInjector.register(CounterLindiViewModel());
  LindiInjector.register(ApiLindiViewModel()..fetchData());
  runApp(const MyApp());
}

// Example App
class MyApp extends StatelessWidget {
  const MyApp({super.key});

  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      title: 'Lindi Example',
      theme: ThemeData(primarySwatch: Colors.blue),
      home: const CounterScreen(),
    );
  }
}

// Counter ViewModel
class CounterLindiViewModel extends LindiViewModel {
  int counter = 0;

  void increment() {
    counter++;
    notify();
  }

  void decrement() {
    counter--;
    notify();
  }
}

/// A ViewModel for handling API calls using the Lindi.
///
/// This class extends `LindiViewModel<String, String>`, meaning it manages:
/// - **Data (`String`)**: The fetched API response.
/// - **Error (`String`)**: Error messages related to the API request.
class ApiLindiViewModel extends LindiViewModel<String, String> {
  void fetchData() async {
    setLoading();
    try {
      await Future.delayed(Duration(seconds: 4));
      setData('Fetched');
    } catch (e) {
      setError('Something went wrong!');
    } finally {
      Future.delayed(Duration(seconds: 4)).then((e) {
        setError('Timeout!');
      });
    }
  }
}

// Counter Screen
class CounterScreen extends StatelessWidget {
  const CounterScreen({super.key});

  @override
  Widget build(BuildContext context) {
    // Retrieve LindiViewModels from the injector
    final counterViewModel = LindiInjector.get<CounterLindiViewModel>();
    final apiViewModel = LindiInjector.get<ApiLindiViewModel>();

    return Scaffold(
      appBar: AppBar(title: const Text('Lindi Example')),
      body: Center(
        child: Column(
          mainAxisAlignment: MainAxisAlignment.spaceEvenly,
          children: [
            Column(
              mainAxisAlignment: MainAxisAlignment.center,
              children: [
                LindiBuilder(
                    viewModel: counterViewModel,
                    builder: (context) {
                      return Text(
                        'Counter: ${counterViewModel.counter}',
                        style: const TextStyle(fontSize: 24),
                      );
                    }),
                const SizedBox(height: 20),
                ElevatedButton(
                  onPressed: counterViewModel.increment,
                  child: const Text('Increment'),
                ),
                ElevatedButton(
                  onPressed: counterViewModel.decrement,
                  child: const Text('Decrement'),
                ),
              ],
            ),
            LindiBuilder(
              viewModel: apiViewModel,
              builder: (context) {
                if (apiViewModel.isLoading) {
                  return CircularProgressIndicator();
                }
                if (apiViewModel.hasError) {
                  return Text(
                    apiViewModel.error!,
                    style: TextStyle(color: Colors.red),
                  );
                }
                return Text(
                  apiViewModel.data!,
                  style: TextStyle(color: Colors.green),
                );
              },
            ),
          ],
        ),
      ),
    );
  }
}

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