Websockets：向除发件人以外的所有客户端发送消息和通知

Question

我正在开发基于 websockets 和 webrtc 的聊天。我想向除发件人以外的所有连接用户发送消息，但我找不到合适的解决方案。更具体地说，我想向其他连接的用户发送新用户已加入聊天的通知。我试图为每个连接的用户提供一个唯一的 ID，但是每个新用户都会重写第一个分配的 ID，我无法区分用户。

服务器：

// list of users
var CLIENTS=[];
var id;

// web server is using 8081 port
var webSocketServer = new WebSocketServer.Server({ port: 8081 });

// check if connection is established
webSocketServer.on('connection', function(ws) {

id = Math.random();
CLIENTS[id] = ws;
CLIENTS.push(ws);

ws.on('message', function(message) {
    console.log('received: %s', message);
    var received = JSON.parse(message);

    if(received.type == "login"){
        ws.send(message);  // send message to itself

        /* *********************************************************** */
        /* *** Here I trying to check if message comes from sender *** */

        sendNotes(JSON.stringify({
            user: received.name,
            type: "notes"
        }), ws, id);

        /* *********************************************************** */
    }else if(received.type == "message"){
        sendAll(message); // broadcast messages to everyone including sender
    }

});

ws.on('close', function() {
    console.log('user ' + CLIENTS[ws] + ' left chat');
    delete CLIENTS[ws];
});

});

function sendNotes(message, ws, id) {
    console.log('sendNotes : ', id);
    if (CLIENTS[id] !== ws) {
        console.log('IF : ', message);
        for (var i = 0; i < CLIENTS.length; i++) {
            CLIENTS[i].send(message);
        }
    }else{
        console.log('ELSE : ', message);
    }
}

   function sendAll(message) {
       for (var i=0; i < CLIENTS.length; i++) {
          CLIENTS[i].send(message); // broadcast messages to everyone including sender
       }
   }

客户：

loginButton.addEventListener("click", function(){
    name = usernameInput.value;

    if(name.length > 0){
        socket.send(JSON.stringify({
            type: "login",
            name: name
        }));
    }

});

function sendData() {
    var data = dataChannelSend.value;
    var userName = document.getElementById('greetingUser').innerHTML;

    socket.send(JSON.stringify({
        username : userName,  // fetch user name from browser, after login
        type : "message",
        message : data
    }));
}

socket.onmessage = function(message) {

    var envelope = JSON.parse(message.data);
    switch(envelope.type) {
        case "login":
            onLogin(envelope);
            break;
        case "message":
            showMessage(envelope);
            break;
    }
};

如果您能给我任何提示，我将不胜感激。谢谢

Answer 1

这是一种非常简单的方法，可以发送给除发件人之外的所有连接的人。

在您的 webSocketServer 实例上创建一个广播函数，它将采用两个参数。

...
var webSocketServer = new WebSocketServer.Server({ port: 8081 });
...
/*
 * method: broadcast
 * @data: the data you wanna send
 * @sender: which client/ws/socket is sending
 */
webSocketServer.broadcast = function(data, sender) {
  webSocketServer.clients.forEach(function(client) {
    if (client !== sender) {
      client.send(data)
    }
  })
}

...
// On your message callback.
ws.on('message', function(message) {
 ...
  // Note that we're passing the (ws) here
  webSocketServer.broadcast(message, ws);
})

就是这样，广播方法将发送到每个连接的客户端，除了正在发送的客户端。