sending a javascript object through websockets with faye

Question

Hi all I'm trying to send a javascript object through websockets:

the faye-websockets documentation says:

send(message) accepts either a String or a Buffer and sends a text or binary message over the connection to the other peer.

server side I'm using node and faye.

var WebSocket = require('faye-websocket'); var http = require('http');  var server = http.createServer(); server.addListener('upgrade', function(request, socket, head) {     var ws = new WebSocket(request, socket, head);     ws.send({topic:'handshake', data:'sdf487rgiuh7'}); }); server.listen(8000); 

client side:

<script>     var ws = new WebSocket('ws://localhost:8000');     ws.onmessage = function(e) {         console.log(e.data); //prints [Object object] string and not the object     }; </script> 

what is my error? Thanks

Answer 1

WebSockets support sending and receiving: strings, typed arrays (ArrayBuffer) and Blobs. Javascript objects must be serialized to one of the above types before sending.

To send an object as a string you can use the builtin JSON support:

ws.send(JSON.stringify(object)); 

To send an object as a typed array you can use a javascript BSON library such as this one:

ws.send(BSON.serialize(object)); 

When you receive a WebSocket message you will need to deserialize it.

To deserialize a JSON string from a WebSocket message:

ws.onmessage = function (e) {     var object = JSON.parse(e.data);     ... }; 

If you are using binary messages over WebSocket, then first you should set the binaryType attribute in order to receive all binary messages as typed arrays:

ws.binaryType = "arraybuffer"; 

Then the deserialization will look like this:

ws.onmessage = function (e) {     var object = BSON.deserialize(e.data);     ... }; 

Here is a blog post about using BSON in Javascript;

Answer 2

I'm basically working with Socket.IO, but it looks like you need to stringify your data in the server and parse it in the client like so:

in the server:

ws.send(JSON.stringify({topic:'handshake', data:'sdf487rgiuh7'})); 

in the client:

console.log(JSON.parse(e.data));