socket.io-parser

What is socket.io-parser?

The socket.io-parser npm package is a component of the Socket.IO ecosystem, which is used for encoding and decoding messages that are sent over the Socket.IO protocol. It handles the serialization and deserialization of the various types of messages that can be transmitted, such as events, binary data, and control packets.

What are socket.io-parser's main functionalities?

Encoding messages

This feature allows you to encode messages into a format that can be transmitted over the Socket.IO protocol. The code sample represents a JSON string that has been encoded by the socket.io-parser for an event with some data.

{"type":2,"nsp":"/","data":["event",{"some":"data"}]}

Decoding messages

This feature is used to decode messages received over the Socket.IO protocol. The code sample shows how an encoded message (a string) is decoded back into its original form using the socket.io-parser.

const encodedMessage = '4hello world';
const decodedMessage = parser.decode(encodedMessage);
console.log(decodedMessage);

Binary support

The socket.io-parser can handle binary data by encoding and decoding it as part of the message. The code sample demonstrates how to encode an ArrayBuffer as binary data within a message.

const binaryData = new ArrayBuffer(100);
const message = parser.encodeAsBinary({ type: 5, data: binaryData });
console.log(message);

Other packages similar to socket.io-parser

engine.io-parser

This package is part of the Engine.IO library, which is a lower-level component of the Socket.IO framework. It provides similar encoding and decoding functionalities for the Engine.IO protocol, which is a bit more focused on the transport layer compared to the higher-level abstraction provided by socket.io-parser.

ws

While not a direct alternative to socket.io-parser, the 'ws' package is a popular WebSocket library for Node.js that allows for sending and receiving data over WebSockets. It handles the WebSocket protocol directly, without the additional features and abstractions that Socket.IO provides.

json-socket

json-socket is a wrapper around the Node.js net library that adds a layer for seamless JSON message sending and receiving. It's similar to socket.io-parser in that it deals with message serialization and deserialization, but it's tailored for use with raw TCP sockets rather than the Socket.IO protocol.

README

socket.io-parser

A socket.io encoder and decoder written in JavaScript complying with version 5 of socket.io-protocol. Used by socket.io and socket.io-client.

Compatibility table:

Parser version	Socket.IO server version	Protocol revision
3.x	1.x / 2.x	4
4.x	3.x	5

Parser API

socket.io-parser is the reference implementation of socket.io-protocol. Read the full API here: socket.io-protocol.

Example Usage

Encoding and decoding a packet

var parser = require('socket.io-parser');
var encoder = new parser.Encoder();
var packet = {
  type: parser.EVENT,
  data: 'test-packet',
  id: 13
};
encoder.encode(packet, function(encodedPackets) {
  var decoder = new parser.Decoder();
  decoder.on('decoded', function(decodedPacket) {
    // decodedPacket.type == parser.EVENT
    // decodedPacket.data == 'test-packet'
    // decodedPacket.id == 13
  });

  for (var i = 0; i < encodedPackets.length; i++) {
    decoder.add(encodedPackets[i]);
  }
});

Encoding and decoding a packet with binary data

var parser = require('socket.io-parser');
var encoder = new parser.Encoder();
var packet = {
  type: parser.BINARY_EVENT,
  data: {i: new Buffer(1234), j: new Blob([new ArrayBuffer(2)])},
  id: 15
};
encoder.encode(packet, function(encodedPackets) {
  var decoder = new parser.Decoder();
  decoder.on('decoded', function(decodedPacket) {
    // decodedPacket.type == parser.BINARY_EVENT
    // Buffer.isBuffer(decodedPacket.data.i) == true
    // Buffer.isBuffer(decodedPacket.data.j) == true
    // decodedPacket.id == 15
  });

  for (var i = 0; i < encodedPackets.length; i++) {
    decoder.add(encodedPackets[i]);
  }
});

See the test suite for more examples of how socket.io-parser is used.

License

MIT