https://github.com/thekeenant/bus

:bus: A light-weight event bus library for Dart implementing the pub-sub pattern.
https://github.com/thekeenant/bus

bus dart dartlang event eventbus library pubsub

Last synced: 5 days ago
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:bus: A light-weight event bus library for Dart implementing the pub-sub pattern.

• Host: GitHub
• URL: https://github.com/thekeenant/bus
• Owner: thekeenant
• License: mit
• Created: 2017-05-18T21:45:48.000Z (over 7 years ago)
• Default Branch: master
• Last Pushed: 2017-10-17T22:28:42.000Z (about 7 years ago)
• Last Synced: 2024-10-13T08:42:37.190Z (23 days ago)
• Topics: bus, dart, dartlang, event, eventbus, library, pubsub
• Language: Dart
• Homepage: https://thekeenant.github.io/bus/
• Size: 656 KB
• Stars: 5
• Watchers: 4
• Forks: 2
• Open Issues: 0
• Metadata Files:
  • Readme: README.md
  • Changelog: CHANGELOG.md
  • License: LICENSE

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README

        
# Event Bus on Dart

A light-weight event bus library for Dart implementing the pub-sub pattern.

Functionality for JavaScript through dart2js is thanks to [dart-patch-mirrors](https://github.com/matthewfranglen/dart-patch-mirrors)

which provides some fixes for the buggy mirror functionality. All the examples provided work with dart2js.

![diagram](http://i.imgur.com/gBnIdO5.png)

Send a message to the bus and let the bus distribute the message to various handlers which are subscribed to that type of

event. This library utilizes the `Stream` async library in Dart to handle subscriptions and publishing messages.

## Install

See [pub.dartlang.org][install] for instructions on how to use bus in your project.

## Usage

A simple usage example:

```dart

import 'package:bus/bus.dart';

main() async {

  var bus = new Bus();

  var sub = bus.subscribe((String message) {

    print('Received a string: "$message"');

  });

  await bus.post('Hey there!');

  

  // cancel the subscription

  sub.cancel();

  

  // the subscription was cancelled, this is pointless

  bus.post('This message will not be heard...');

}

```

Also supported is subscribing an object full of handlers:

```dart

class GameListener implements Listener {

  @handler

  void _onGame(GameEvent event) {

    print('[An event occurred at ${event.timestamp}]');

  }

  @handler

  void _onChat(ChatEvent event) {

    print('${event.username} says "${event.message}"');

  }

}

...

var bus = new Bus();

var subs = bus.subscribeAll(new GameListener()); // returns a list of subscriptions

// remember to cancel your event subscriptions

subs.forEach((s) => s.cancel());

```

See the [game example][game] for more details.

For your synchronous needs, you can use `SyncBus` to publish and handle messages synchronously.

## Web Demo

Visit [https://thekeenant.github.io/bus/](https://thekeenant.github.io/bus/). Try it yourself

by cloning this repository and running `pub serve web`. This will serve the assets in the `web` directory.

## Features and bugs

Please file feature requests and bugs at the [issue tracker][tracker].

[install]: https://pub.dartlang.org/packages/bus#-pkg-tab-installing

[game]: https://github.com/thekeenant/dart-bus/blob/master/example/bus_game.dart

[tracker]: https://github.com/thekeenant/dart-bus/issues