engine.io-parser


This is the JavaScript parser for the engine.io protocol encoding,
shared by both
engine.io-client and
engine.io.

How to use

$3

The parser can encode/decode packets, payloads, and payloads as binary
with the following methods: encodePacket, decodePacket, encodePayload,
decodePayload.

Example:

``js
const parser = require("engine.io-parser");
const data = Buffer.from([ 1, 2, 3, 4 ]);

parser.encodePacket({ type: "message", data }, encoded => {
const decodedData = parser.decodePacket(encoded); // decodedData === data
});
`

$3

Engine.IO Parser is a commonjs module, which means you can include it by using
require on the browser and package using browserify:

1. install the parser package

`shell
npm install engine.io-parser
`

1. write your app code

`js
const parser = require("engine.io-parser");

const testBuffer = new Int8Array(10);
for (let i = 0; i < testBuffer.length; i++) testBuffer[i] = i;

const packets = [{ type: "message", data: testBuffer.buffer }, { type: "message", data: "hello" }];

parser.encodePayload(packets, encoded => {
parser.decodePayload(encoded,
(packet, index, total) => {
const isLast = index + 1 == total;
if (!isLast) {
const buffer = new Int8Array(packet.data); // testBuffer
} else {
const message = packet.data; // "hello"
}
});
});
`

1. build your app bundle

`bash
$ browserify app.js > bundle.js
`

1. include on your page

`html

`

Features

- Runs on browser and node.js seamlessly
- Runs inside HTML5 WebWorker
- Can encode and decode packets
- Encodes from/to ArrayBuffer or Blob when in browser, and Buffer or ArrayBuffer in Node

API

Note: cb(type) means the type is a callback function that contains a parameter of type type when called.

$3

- encodePacket
- Encodes a packet.
- Parameters
- Object: the packet to encode, has type and data.
- data: can be a String, Number, Buffer, ArrayBuffer
- Boolean: binary support
- Function: callback, returns the encoded packet (cb(String))
- decodePacket
- Decodes a packet. Data also available as an ArrayBuffer if requested.
- Returns data as String or (Blob on browser, ArrayBuffer on Node)
- Parameters
- String | ArrayBuffer: the packet to decode, has type and data
- String: optional, the binary type

- encodePayload
- Encodes multiple messages (payload).
- If any contents are binary, they will be encoded as base64 strings. Base64
encoded strings are marked with a b before the length specifier
- Parameters
- Array: an array of packets
- Function: callback, returns the encoded payload (cb(String))
- decodePayload
- Decodes data when a payload is maybe expected. Possible binary contents are
decoded from their base64 representation.
- Parameters
- String: the payload
- Function: callback, returns (cb(Object: packet, Number:packet index, Number:packet total))

Tests

Standalone tests can be run with npm test which will run the node.js tests.

Browser tests are run using zuul.
(You must have zuul setup with a saucelabs account.)

You can run the tests locally using the following command:

`
npm run test:browser
`

Support

The support channels for engine.io-parser are the same as socket.io:
- irc.freenode.net #socket.io
- Github Discussions
- Website

Development

To contribute patches, run tests or benchmarks, make sure to clone the
repository:

`bash
git clone git://github.com/socketio/engine.io-parser.git
`

Then:

`bash
cd engine.io-parser
npm ci
`

See the Tests` section above for how to run tests before submitting any patches.

License

MIT