Contexto

A simple library to avoid prop drilling in Flutter using a context system similar to Context API from React.

✨ Features

  • Provision of status via AppContext.provider.
  • Easy access to status with useContext<T>(context).
  • Dispatch function with useDispatch<T>(context).
  • Automatic updates for dependent widgets.

📦 Installation

Add the dependency to your pubspec.yaml:

dependencies:
  contexto: ^1.0.0

Run the command to install the package:

dart pub get

🚀 How to use

Creating a Context Provider

Wrap the widgets that need to access the state or value inside an AppContext.provider.

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

void main() {
  runApp(MyApp());
}

class MyApp extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      home: AppContext.provider<int>(
        value: 0,
        child: CounterScreen(),
      ),
    );
  }
}

Accessing and updating values

Use useContext<T>(context) to access the state/value and useDispatch<T>(context) to update it.

class CounterScreen extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    final counter = useContext<int>(context);
    final setCounter = useDispatch<int>(context);
    
    return Scaffold(
      appBar: AppBar(title: Text("Counter")),
      body: Center(
        child: Column(
          mainAxisAlignment: MainAxisAlignment.center,
          children: [
            Text("Value: \$counter", style: TextStyle(fontSize: 24)),
            Row(
              mainAxisAlignment: MainAxisAlignment.center,
              children: [
                IconButton(
                  onPressed: () => setCounter(counter - 1),
                  icon: Icon(Icons.remove),
                ),
                IconButton(
                  onPressed: () => setCounter(counter + 1),
                  icon: Icon(Icons.add),
                ),
              ],
            ),
          ],
        ),
      ),
    );
  }
}

🛠 API

AppContext.provider<T>

A provider that makes a value available to descendant widgets without the need for prop drilling.

Parameters:

  • value (T): Initial value.
  • child (Widget): The child widget that will access the value.

useContext<T>(context)

Returns the value of type T from the nearest provider.

Use:

final value = useContext<MyType>(context);

useDispatch<T>(context)

Returns a function to update the value of type T in the nearest provider.

Use:

final dispatch = useDispatch<int>(context);
dispatch(42); // Updates the state to 42

🧪 Tests

To run the tests, execute the command:

dart test

🚀 Contributing

Contributions are welcome! Please submit pull requests with any improvements or bug fixes.

📝 License

This project is licensed under the BSD 3 License - see the LICENSE file for details.

Libraries

contexto