- Easy-to-use websocket methods and usage examples included!
- Universal socket status changes stream.
- Ping delay measurement and easy setup for ping/pong interaction with server!
- Auto-reconnection feature for
IWebSocketHandler
ws handler.
// ignore_for_file: avoid_print
import 'package:websocket_universal/websocket_universal.dart';
/// Example works with Postman Echo server
void main() async {
/// 1. Create webSocket handler:
final textSocketHandler = IWebSocketHandler<String, String>.createClient(
'wss://ws.postman-echo.com/raw', // Postman echo ws server
SocketSimpleTextProcessor(),
);
/// 2. Listen to webSocket messages:
textSocketHandler.incomingMessagesStream.listen((inMsg) {
print('> webSocket got text message from server: "$inMsg" '
'[ping: ${textSocketHandler.pingDelayMs}]');
});
textSocketHandler.outgoingMessagesStream.listen((inMsg) {
print('> webSocket sent text message to server: "$inMsg" '
'[ping: ${textSocketHandler.pingDelayMs}]');
});
/// 3. Connect & send message:
await textSocketHandler.connect();
textSocketHandler.sendMessage('Hello server!');
await Future<void>.delayed(const Duration(seconds: 4));
// 4. Disconnect & close connection:
await textSocketHandler.disconnect('manual disconnect');
textSocketHandler.close();
}
You don't need your own ws server to run this code.
Example postman echo server is used in this example.
- Send message to server using
sendMessage(Y messageToServer)
and listen messages coming from server usingincomingMessagesStream
- Listen to websocket states
socketStateStream
or all events that are happeninglogEventStream
. Define how you process your messages to and from server and ping/pong interaction usingIMessageProcessor<Tin,Yout>
generic interface or use convinientSocketMessageProcessor
implementation (see example #2).
import 'package:websocket_universal/websocket_universal.dart';
/// Example works with Postman Echo server
void main() async {
/// Postman echo ws server (you can use your own server URI)
/// 'wss://ws.postman-echo.com/raw'
/// For local server it could look like 'ws://127.0.0.1:42627/websocket'
const websocketConnectionUri = 'wss://ws.postman-echo.com/raw';
const textMessageToServer = 'Hello server!';
const connectionOptions = SocketConnectionOptions(
pingIntervalMs: 3000, // send Ping message every 3000 ms
timeoutConnectionMs: 4000, // connection fail timeout after 4000 ms
/// see ping/pong messages in [logEventStream] stream
skipPingMessages: false,
/// Set this attribute to `true` if do not need any ping/pong
/// messages and ping measurement. Default is `false`
pingRestrictionForce: false,
);
/// Example with simple text messages exchanges with server
/// (not recommended for applications)
/// [<String, String>] generic types mean that we receive [String] messages
/// after deserialization and send [String] messages to server.
final IMessageProcessor<String, String> textSocketProcessor =
SocketSimpleTextProcessor();
final textSocketHandler = IWebSocketHandler<String, String>.createClient(
websocketConnectionUri, // Postman echo ws server
textSocketProcessor,
connectionOptions: connectionOptions,
);
// Listening to webSocket status changes
textSocketHandler.socketHandlerStateStream.listen((stateEvent) {
// ignore: avoid_print
print('> status changed to ${stateEvent.status}');
});
// Listening to server responses:
textSocketHandler.incomingMessagesStream.listen((inMsg) {
// ignore: avoid_print
print('> webSocket got text message from server: "$inMsg" '
'[ping: ${textSocketHandler.pingDelayMs}]');
});
// Listening to debug events inside webSocket
textSocketHandler.logEventStream.listen((debugEvent) {
// ignore: avoid_print
print('> debug event: ${debugEvent.socketLogEventType}'
' [ping=${debugEvent.pingMs} ms]. Debug message=${debugEvent.message}');
});
// Listening to outgoing messages:
textSocketHandler.outgoingMessagesStream.listen((inMsg) {
// ignore: avoid_print
print('> webSocket sent text message to server: "$inMsg" '
'[ping: ${textSocketHandler.pingDelayMs}]');
});
// Connecting to server:
final isTextSocketConnected = await textSocketHandler.connect();
if (!isTextSocketConnected) {
// ignore: avoid_print
print('Connection to [$websocketConnectionUri] failed for some reason!');
return;
}
textSocketHandler.sendMessage(textMessageToServer);
await Future<void>.delayed(const Duration(seconds: 30));
// Disconnecting from server:
await textSocketHandler.disconnect('manual disconnect');
// Disposing webSocket:
textSocketHandler.close();
}
You don't need your own ws server to run this code.
Example postman echo server is used in this example.
import 'package:websocket_universal/websocket_universal.dart';
void main() async {
/// Postman echo ws server (you can use your own server URI)
/// For local server it could look like 'ws://127.0.0.1:42627/websocket'
const websocketConnectionUri = 'wss://ws.postman-echo.com/raw';
const textMessageToServer = 'Hello server!';
const connectionOptions = SocketConnectionOptions(
pingIntervalMs: 3000, // send Ping message every 3000 ms
timeoutConnectionMs: 4000, // connection fail timeout after 4000 ms
/// see ping/pong messages in [logEventStream] stream
skipPingMessages: false,
);
/// Complex example:
/// Example using [ISocketMessage] and [IMessageToServer]
/// (recommended for applications, server must deserialize
/// [ISocketMessage] serialized string to [ISocketMessage] object)
final IMessageProcessor<ISocketMessage<Object?>, IMessageToServer>
messageProcessor = SocketMessageProcessor();
final socketHandler =
IWebSocketHandler<ISocketMessage<Object?>, IMessageToServer>.createClient(
websocketConnectionUri,
messageProcessor,
connectionOptions: connectionOptions,
);
// Listening to debug events inside webSocket
socketHandler.logEventStream.listen((debugEvent) {
// ignore: avoid_print
print('> debug event: ${debugEvent.socketLogEventType}'
' ping=${debugEvent.pingMs} ms. Debug message=${debugEvent.message}');
});
// Listening to webSocket status changes
socketHandler.socketStateStream.listen((stateEvent) {
// ignore: avoid_print
print('> status changed to ${stateEvent.status}');
});
// [IMessageToServer] also implements [ISocketMessage] interface.
// So basically we are sending and receiving equally-typed messages.
const messageTypeStr = '[ISocketMessage]';
// Listening to server responses:
socketHandler.incomingMessagesStream.listen((inMsg) {
// ignore: avoid_print
print('> webSocket got $messageTypeStr: $inMsg');
});
// Listening to outgoing messages:
socketHandler.outgoingMessagesStream.listen((inMsg) {
// ignore: avoid_print
print('> webSocket sent $messageTypeStr: $inMsg');
});
// Connecting to server:
final isConnected = await socketHandler.connect();
if (!isConnected) {
// ignore: avoid_print
print('Connection to [$websocketConnectionUri] failed for some reason!');
return;
}
// Sending message with routing path 'test' and simple JSON payload:
final outMsg = MessageToServerImpl.onlyHost(
host: 'test',
data: '{"payload": "$textMessageToServer"}',
error: null,
);
socketHandler.sendMessage(outMsg);
await Future<void>.delayed(const Duration(seconds: 8));
// Disconnecting from server:
await socketHandler.disconnect('manual disconnect');
// Disposing webSocket:
socketHandler.close();
}
import 'dart:convert';
import 'package:websocket_universal/websocket_universal.dart';
/// Bytes array example:
void main() async {
/// For getting/answering byte-array messages (`List<int> in dart`)
/// you will need your own server and handle messages as byte-arrays
/// on the backend side too. On client side it will look like this:
const websocketLocalExample = 'ws://127.0.0.1:42627/websocket';
const textMessageToServer = 'Hello server!';
const connectionOptions = SocketConnectionOptions(
pingIntervalMs: 3000, // send Ping message every 3000 ms
timeoutConnectionMs: 4000, // connection fail timeout after 4000 ms
/// see ping/pong messages in [logEventStream] stream
skipPingMessages: false,
);
final IMessageProcessor<List<int>, List<int>> bytesSocketProcessor =
SocketSimpleBytesProcessor();
final bytesSocketHandler =
IWebSocketHandler<List<int>, List<int>>.createClient(
websocketLocalExample, // Local ws server
bytesSocketProcessor,
connectionOptions: connectionOptions,
);
// Listening to debug events inside webSocket
bytesSocketHandler.logEventStream.listen((debugEvent) {
// ignore: avoid_print
print('> debug event: ${debugEvent.socketLogEventType}'
' ping=${debugEvent.pingMs} ms. Debug message=${debugEvent.message}');
});
// Listening to server responses:
bytesSocketHandler.incomingMessagesStream.listen((inMsg) {
// ignore: avoid_print
print('> webSocket got bytes message from server: "$inMsg"');
});
// Listening to outgoing messages:
bytesSocketHandler.outgoingMessagesStream.listen((inMsg) {
// ignore: avoid_print
print('> webSocket sent bytes message to server: "$inMsg"');
});
// Connecting to server:
final isBytesSocketConnected = await bytesSocketHandler.connect();
if (!isBytesSocketConnected) {
// ignore: avoid_print
print('Connection to [$websocketLocalExample] for bytesSocketHandler '
'failed for some reason!');
return;
}
final bytesMessage = utf8.encode(textMessageToServer);
//textMessageToServer
bytesSocketHandler.sendMessage(bytesMessage);
await Future<void>.delayed(const Duration(seconds: 7));
// Disconnecting from server:
await bytesSocketHandler.disconnect('manual disconnect');
// Disposing webSocket:
bytesSocketHandler.close();
}
import 'dart:convert';
import 'package:websocket_universal/websocket_universal.dart';
void main() async {
/// Postman echo ws server (you can use your own server URI)
/// For local server it could look like 'ws://127.0.0.1:42627/websocket'
const websocketConnectionUri = 'wss://ws.postman-echo.com/raw';
const connectionOptions = SocketConnectionOptions(
pingIntervalMs: 3000, // send Ping message every 3000 ms
timeoutConnectionMs: 4000, // connection fail timeout after 4000 ms
/// see ping/pong messages in [logEventStream] stream
skipPingMessages: false,
);
/// Complex example:
/// Example using [ISocketMessage] and [IMessageToServer]
/// (recommended for applications, server must deserialize
/// [ISocketMessage] serialized string to [ISocketMessage] object)
final IMessageProcessor<ISocketMessage<Object?>, IMessageToServer>
messageProcessor = SocketMessageProcessor();
final socketHandler =
IWebSocketHandler<ISocketMessage<Object?>, IMessageToServer>.createClient(
websocketConnectionUri,
messageProcessor,
connectionOptions: connectionOptions,
);
/// Creating websocket_manager:
/// `ISocketManagerMiddleware` processes requests before sending and
/// after receiving ISocketMessage. See test implementation for details.
final ISocketManagerMiddleware middleware = SocketManagerMiddleware();
final IWebSocketRequestManager requestManager = WebSocketRequestManager(
middleware: middleware,
webSocketHandler: socketHandler,
);
final IWebSocketDataBridge dataBridge = WebSocketDataBridge(requestManager);
///
// Connecting to server:
final isConnected = await socketHandler.connect();
if (!isConnected) {
// ignore: avoid_print
print('Connection to [$websocketConnectionUri] failed for some reason!');
return;
}
// Sending message with routing path 'test' and simple JSON payload:
final requestGame = MessageToServerImpl.duo(
host: TestDecoder.host,
topic1: CustomGameModel.topic1,
data: jsonEncode(
const CustomGameModel(
name: 'MakeWorld strategy',
playersAmount: 8,
),
),
error: null,
);
final socketRequest = SocketRequest(requestMessage: requestGame);
final result =
await dataBridge.singleRequestFull<CustomGameModel>(socketRequest);
// ignore: avoid_print
print('Got result: ${result.data}');
final outMsgList = MessageToServerImpl.duo(
host: TestDecoder.host,
topic1: CustomGameModel.topic1List,
data: jsonEncode([
const CustomGameModel(
name: 'MakeWorld strategy',
playersAmount: 8,
),
const CustomGameModel(
name: 'New patch',
playersAmount: 4,
),
]),
error: null,
);
final socketRequestList = SocketRequest(requestMessage: outMsgList);
final listResult = await dataBridge
.singleRequestFull<List<CustomGameModel>>(socketRequestList);
// ignore: avoid_print
print('Got list result: ${listResult.data}');
// Creating composite request with 2 response topics required
final topicSingle = SocketTopicImpl.duo(
host: TestDecoder.host,
topic1: CustomGameModel.topic1,
);
final topicList = SocketTopicImpl.duo(
host: TestDecoder.host,
topic1: CustomGameModel.topic1List,
);
// Assemple composite request, that, in fact, requests CustomGameModel
// using [requestGame] to request single game and awaits to receive 2 topics
// from server: [topicSingle] and [topicList]
final compositeRequest = SocketRequest(
requestMessage: requestGame,
responseTopics: {topicSingle, topicList},
);
// Running task:
final compositeTask = dataBridge.compositeRequest(compositeRequest);
// Emulating server 2nd response (real server should response with 2
// messages without 2nd request)
dataBridge.requestData(socketRequestList);
final compositeResp = await compositeTask;
// In result we can get multiple results from composite response:
final responseOne = compositeResp.getData<CustomGameModel>();
final responseTwo = compositeResp.getData<List<CustomGameModel>>();
// ignore: avoid_print
print('Got composite result. Answers = ${compositeResp.dataCached.length}'
'[$responseOne] and [$responseTwo]');
// Disconnecting from server:
await socketHandler.disconnect('manual disconnect');
// Disposing webSocket:
requestManager.close();
socketHandler.close();
}