declarative_async_widget 0.0.1

FutureWidget and StreamWidget - Declarative FutureBuilder and StreamBuilder

FutureWidget and StreamWidget - Improved FutureBuilder and StreamBuilder.

This package provides FutureWidget and StreamWidget, a widget similar to StreamBuilder / FutureBuilder which is designed to reduce boilerplate and improve error handling. It is a rewrite of the package async_builder.

How to use

1. Add to dependencies

dependencies:
  declarative_async_widget: ^latest # replace latest with version number

2. Import

import 'package:declarative_async_widget/declarative_async_widget.dart';

FutureWidget

The [future] can't be null.

Remember to specify the type, e.g., FutureWidget<int>.noError_noLoading and not FutureWidget.noError_noLoading, otherwise a dynamic or a nullable type might be inferred.

Default constructor

whenData, whenError and whenLoading are required. initialData can't be assigned since whenLoading is going to be used instead.

class ExampleWidget extends StatefulWidget {
  const ExampleWidget({Key? key}) : super(key: key);

  @override
  ExampleWidgetState createState() => ExampleWidgetState();
}

class ExampleWidgetState extends State<ExampleWidget> {
  final Future<int> _getInt = myFuture(false);

  static Future<int> myFuture(bool shouldThrow) async {
    await Future.delayed(const Duration(seconds: 4));
    if (shouldThrow) {
      throw Exception("You can't pass true as a param");
    }
    return 4;
  }

  @override
  Widget build(BuildContext context) {
    return FutureWidget<int>(
      future: _getInt,
      whenData: (context, data) => Text('My data is: $data'),
      whenError: (context, error, stackTrace) => Text('Error was thrown: $error'),
      whenLoading: (context) => const Text('Loading...'),
    );
  }
}

noError constructor

There is no whenError param. Make 100% sure the future can't throw an error, else an AsyncWidgetUnexpectedError will be thrown at runtime.

class ExampleWidgetState extends State<ExampleWidget> {
  final Future<int> _getInt = myFuture();

  static Future<int> myFuture() async {
    await Future.delayed(const Duration(seconds: 4));
    return 4;
  }

  @override
  Widget build(BuildContext context) {
    return FutureWidget<int>.noError(
      future: _getInt,
      whenData: (context, data) => Text('My data is: $data'),
      whenLoading: (context) => const Text('Loading...'),
    );
  }
}

noLoading constructor

An initialData is required. There is therefore no whenLoading param.

class ExampleWidgetState extends State<ExampleWidget> {
  final Future<int> _getInt = myFuture(true);

  static Future<int> myFuture(bool shouldThrow) async {
    await Future.delayed(const Duration(seconds: 4));
    if (shouldThrow) {
      throw Exception("You can't pass true as a param");
    }
    return 4;
  }

  @override
  Widget build(BuildContext context) {
    return FutureWidget<int>.noLoading(
      future: _getInt,
      whenData: (context, data) => Text('My data is: $data'),
      initialData: 99999,
      whenError: (BuildContext context, Object error, StackTrace? stackTrace) =>
          Text('Error was thrown: $error'),
    );
  }
}

noError_noLoading constructor

class ExampleWidgetState extends State<ExampleWidget> {
  final Future<int> _getInt = myFuture();

  static Future<int> myFuture() async {
    await Future.delayed(const Duration(seconds: 4));
    return 4;
  }

  @override
  Widget build(BuildContext context) {
    return FutureWidget<int>.noError_noLoading(
      future: _getInt,
      whenData: (context, data) => Text('My data is: $data'),
      initialData: 99999,
    );
  }
}

StreamWidget

It is similar to FutureWidget, but uses streams. More examples will be added in the future.

Note

Complete documentation, tests, a proper example will be added in the future.