web_socket_channel 1.0.9

  • Readme
  • Changelog
  • Installing
  • 72

The web_socket_channel package provides StreamChannel wrappers for WebSocket connections. It provides a cross-platform WebSocketChannel API, a cross-platform implementation of that API that communicates over an underlying StreamChannel, an implementation that wraps dart:io's WebSocket class, and a similar implementation that wrap's dart:html's.

It also provides constants for the WebSocket protocol's pre-defined status codes in the status.dart library. It's strongly recommended that users import this library should be imported with the prefix status.

import 'package:web_socket_channel/io.dart';
import 'package:web_socket_channel/status.dart' as status;

main() async {
  var channel = await IOWebSocketChannel.connect("ws://localhost:1234");

  channel.stream.listen((message) {
    channel.sink.add("received!");
    channel.close(status.goingAway);
  });
}

WebSocketChannel #

The WebSocketChannel class's most important role is as the interface for WebSocket stream channels across all implementations and all platforms. In addition to the base StreamChannel interface, it adds a protocol getter that returns the negotiated protocol for the socket, as well as closeCode and closeReason getters that provide information about why the socket closed.

The channel's sink property is also special. It returns a WebSocketSink, which is just like a StreamSink except that its close() method supports optional closeCode and closeReason parameters. These parameters allow the caller to signal to the other socket exactly why they're closing the connection.

WebSocketChannel also works as a cross-platform implementation of the WebSocket protocol. Because it can't initiate or handle HTTP requests in a cross-platform way, the new WebSocketChannel() constructor takes an underlying StreamChannel over which it communicates using the WebSocket protocol. It also provides the static signKey() method to make it easier to implement the initial WebSocket handshake. These are used in the shelf_web_socket package to support WebSockets in a cross-platform way.

IOWebSocketChannel #

The IOWebSocketChannel class wraps dart:io's WebSocket class. Because it imports dart:io, it has its own library, package:web_socket_channel/io.dart. This allows the main WebSocketChannel class to be available on all platforms.

An IOWebSocketChannel can be created by passing a dart:io WebSocket to its constructor. It's more common to want to connect directly to a ws:// or wss:// URL, in which case new IOWebSocketChannel.connect() should be used.

import 'package:web_socket_channel/io.dart';

main() async {
  var channel = new IOWebSocketChannel.connect("ws://localhost:8181");
  channel.sink.add("connected!");
  channel.stream.listen((message) {
    // ...
  });
}

HtmlWebSocketChannel #

The HtmlWebSocketChannel class wraps dart:html's WebSocket class. Because it imports dart:html, it has its own library, package:web_socket_channel/html.dart. This allows the main WebSocketChannel class to be available on all platforms.

An HtmlWebSocketChannel can be created by passing a dart:html WebSocket to its constructor. It's more common to want to connect directly to a ws:// or wss:// URL, in which case new HtmlWebSocketChannel.connect() should be used.

import 'package:web_socket_channel/html.dart';

main() async {
  var channel = new HtmlWebSocketChannel.connect("ws://localhost:8181");
  channel.sink.add("connected!");
  channel.stream.listen((message) {
    // ...
  });
}

1.0.9 #

  • Set max SDK version to <3.0.0.

1.0.8 #

  • Remove use of deprecated constant name.

1.0.7 #

  • Support the latest dev SDK.

1.0.6 #

  • Declare support for async 2.0.0.

1.0.5 #

  • Increase the SDK version constraint to <2.0.0-dev.infinity.

1.0.4 #

  • Support crypto 2.0.0.

1.0.3 #

  • Fix all strong-mode errors and warnings.

  • Fix a bug where HtmlWebSocketChannel.close() would crash on non-Dartium browsers if the close code and reason weren't provided explicitly.

1.0.2 #

  • Properly use BASE64 from dart:convert rather than crypto.

1.0.1 #

  • Add support for crypto 1.0.0.

1.0.0 #

  • Initial version

Use this package as a library

1. Depend on it

Add this to your package's pubspec.yaml file:


dependencies:
  web_socket_channel: ^1.0.9

2. Install it

You can install packages from the command line:

with pub:


$ pub get

with Flutter:


$ flutter pub get

Alternatively, your editor might support pub get or flutter pub get. Check the docs for your editor to learn more.

3. Import it

Now in your Dart code, you can use:


import 'package:web_socket_channel/web_socket_channel.dart';
  
Popularity:
Describes how popular the package is relative to other packages. [more]
98
Health:
Code health derived from static analysis. [more]
75
Maintenance:
Reflects how tidy and up-to-date the package is. [more]
0
Overall:
Weighted score of the above. [more]
72
Learn more about scoring.

We analyzed this package on Feb 27, 2020, and provided a score, details, and suggestions below. Analysis was completed with status completed using:

  • Dart: 2.7.1
  • pana: 0.13.5

Health suggestions

Fix lib/src/copy/web_socket_impl.dart. (-25 points)

Analysis of lib/src/copy/web_socket_impl.dart reported 59 hints, including:

line 26 col 14: The declaration '_webSocketGUID' isn't referenced.

line 27 col 14: The declaration '_clientNoContextTakeover' isn't referenced.

line 28 col 14: The declaration '_serverNoContextTakeover' isn't referenced.

line 29 col 14: The declaration '_clientMaxWindowBits' isn't referenced.

line 30 col 14: The declaration '_serverMaxWindowBits' isn't referenced.

Fix lib/src/copy/bytes_builder.dart. (-6.31 points)

Analysis of lib/src/copy/bytes_builder.dart reported 13 hints, including:

line 27 col 34: Use = to separate a named parameter from its default value.

line 29 col 14: Unnecessary new keyword.

line 31 col 14: Unnecessary new keyword.

line 74 col 29: Unnecessary new keyword.

line 82 col 15: Unnecessary new keyword.

Fix lib/src/copy/io_sink.dart. (-4.41 points)

Analysis of lib/src/copy/io_sink.dart reported 9 hints, including:

line 18 col 36: Unnecessary new keyword.

line 46 col 13: Unnecessary new keyword.

line 65 col 13: Unnecessary new keyword.

line 67 col 45: Unnecessary new keyword.

line 80 col 13: Unnecessary new keyword.

Fix additional 4 files with analysis or formatting issues. (-10.39 points)

Additional issues in the following files:

  • lib/io.dart (7 hints)
  • lib/html.dart (6 hints)
  • lib/src/channel.dart (4 hints)
  • lib/src/sink_completer.dart (4 hints)

Maintenance issues and suggestions

Support latest dependencies. (-10 points)

The version constraint in pubspec.yaml does not support the latest published versions for 1 dependency (stream_channel).

Package is getting outdated. (-61.37 points)

The package was last published 84 weeks ago.

The package description is too short. (-20 points)

Add more detail to the description field of pubspec.yaml. Use 60 to 180 characters to describe the package, what it does, and its target use case.

Maintain an example. (-10 points)

Create a short demo in the example/ directory to show how to use this package.

Common filename patterns include main.dart, example.dart, and web_socket_channel.dart. Packages with multiple examples should provide example/README.md.

For more information see the pub package layout conventions.

Dependencies

Package Constraint Resolved Available
Direct dependencies
Dart SDK >=2.0.0-dev.23.0 <3.0.0
async >=1.3.0 <3.0.0 2.4.0
crypto >=0.9.2 <3.0.0 2.1.4
stream_channel ^1.2.0 1.7.0 2.0.0
Transitive dependencies
charcode 1.1.3
collection 1.14.12
convert 2.1.1
typed_data 1.1.6
Dev dependencies
test ^1.2.0