CODEWITHSUNDEEP
node.jssocket.io
xjq233p_1
xjq233p_1

Reputation: 8060

Overriding socket.io's emit and on?

During development, it helps me greatly to be able to see what packets arrive and gets sent. This is possible on the server side with logger. On the client end, however, there is no logger. I find myself to be littering console.log all over the place.

Is it possible to override socket.emit and socket.on with console.log(arguments)? If I can override this at the before my socket, it would be really elegant.

Somebody advised me to override the Parser instead.

What's your 2cents on this?

EDIT

I tried Kato's suggestion and wrote the following: 

var _origEmit = socket.emit;
socket.emit = function() { 
  console.log("SENT", Array.prototype.slice.call(arguments));
  _origEmit.call(socket, arguments);
};

This works. However, Not so much with socket.on. My strategy is to wrap each callback with a console.log. If you know python, it's kind of like putting function decorators on the callbacks that console.log the arguments. 

(function(socket) { 
var _origOn = socket.on;
socket.on = function() { 
  var args = Array.prototype.slice.call(arguments)
    , handlerType = args[0]
    , originalCallback = args[1];

  var wrappedCallback = function() { 
    // replace original callback with a function 
    // wrapped around by console.log
    console.log("RECEIVED", Array.prototype.slice.call(arguments));
    originalCallback.call(socket, arguments);
  }

  _origOn.call(socket, [handlerType, wrappedCallback]);
}

Any one can point to why monkey patching socket.on is not working?

Upvotes: 24

Views: 15456

Answers (4)

Marian Klühspies
Marian Klühspies

Reputation: 17637

There is a module called socket.io-wildcard which allows using wildcards on client and server side, no need to overwrite anything anymore

var io         = require('socket.io')();
var middleware = require('socketio-wildcard')();

io.use(middleware);

io.on('connection', function(socket) {
  socket.on('*', function(){ /* … */ });
});

io.listen(8000);

Upvotes: 4

Alexander Art
Alexander Art

Reputation: 1589

Works, tested:

var _emit = socket.emit;
    _onevent = socket.onevent;

    socket.emit = function () { //Override outgoing
        //Do your logic here
        console.log('***', 'emit', arguments);
        _emit.apply(socket, arguments);
    };

    socket.onevent = function (packet) { //Override incoming
        var args = packet.data || [];
        //Do your logic here
        console.log('***', 'onevent', packet);
        _onevent.call(socket, packet);
    };

Upvotes: 5

Kato
Kato

Reputation: 40582

<script src="/socket.io/socket.io.js"></script>
<script>
  (function() {

      var _origEmit = socket.emit;
      socket.emit = function() {
         console.log(arguments);
         _origEmit.apply(null, Array.prototype.slice.call(arguments));
      };


  })();
</script>

Upvotes: 0

hvqzao
hvqzao

Reputation: 1045

To override socket.on you actually need to override socket.$emit.

Following example works both client and server-side (tested on socket.io 0.9.0):

(function() {
  var emit = socket.emit;
  socket.emit = function() {
    console.log('***','emit', Array.prototype.slice.call(arguments));
    emit.apply(socket, arguments);
  };
  var $emit = socket.$emit;
  socket.$emit = function() {
    console.log('***','on',Array.prototype.slice.call(arguments));
    $emit.apply(socket, arguments);
  };
})();

Upvotes: 58

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