Specific options to nodejs ws.Server

Question

Can someone explain me what disableHixie, clientTracking in nodejs websocket library 'ws' means:

new ws.Server([options], [callback])

options Object
host String
port Number
server http.Server
verifyClient Function
path String
noServer Boolean
disableHixie Boolean
clientTracking Boolean
callback Function

I can't find a conclusive description what it means.

Answer 1

Hixie-76 is an old and deprecated protocol supported by WebSocket, but this protocol is still in use in some versions of Safari and Opera. Default value in library 'ws' is false , but you can disable the setting and set the disableHixie option to true .

The clientTracking option provides access to a collection of active WebSocket clients. Default value is true . See below:

var wss = new WebSocketServer({server:app });

wss.on('connection', function (ws) {
   .....
   console.log('Total clients: ', wss.clients.length);
   ....
}

Edit: additional information:

The verifyClient function allows you to add any custom code to accept or reject incoming connections. Your code receives an info object with three members:

• info.origin: The origin of the connection
• info.secure: True if this connection is authorized or encrypted
• info.req: The http.Server request object for this connection

The verifyClient function can take one of the two forms:

var wss1 = new WebSocketServer ({ ..., 
   verifyClient: function(info) {
      # ...check data in info and return true or false...
   }
);

var wss2 = new WebSocketServer ({ ..., 
   verifyClient: function(info, callback){
      # ...check data in info and call
      # callback(true) for success or
      # callback(false) for failure 
   }
});

The first form is simpler if you can validate the client immediately. For asynchronous validation, use the second form.