cobalt_flutter 1.7.0

Dependency injection for Flutter apps. Widgets own scopes, startup shows loading and error screens, and context.cobalt<T>() reads a dependency in any widget.

example/example.md

cobalt_flutter example

CobaltAppScope owns the root scope for as long as the app is mounted. Its usual home is MaterialApp.builder, where the loading and error screens are rendered with the app's own theme.

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

void main() => runApp(
  MaterialApp(
    theme: ThemeData(colorSchemeSeed: Colors.indigo),
    builder: CobaltAppScope.builder(
      root: const AppScope(),
      rootName: 'app',
      loading: const Scaffold(body: Center(child: CircularProgressIndicator())),
      errorBuilder: (context, error, retry) => Scaffold(
        body: Center(
          child: Column(
            mainAxisSize: MainAxisSize.min,
            children: [
              Text('$error'),
              FilledButton(onPressed: retry, child: const Text('Try again')),
            ],
          ),
        ),
      ),
    ),
    home: const HomeScreen(),
  ),
);

class HomeScreen extends StatelessWidget {
  const HomeScreen({super.key});

  @override
  Widget build(BuildContext context) =>
      Scaffold(body: Center(child: Text('${context.cobalt<Database>()}')));
}

A scope that lives as long as one screen is CobaltScopeWidget; a full app with one screen per capability is examples/notes_app.