1
  2# engine.io-parser
  3
  4[![Build Status](https://secure.travis-ci.org/socketio/engine.io-parser.svg)](http://travis-ci.org/socketio/engine.io-parser)
  5[![NPM version](https://badge.fury.io/js/engine.io-parser.svg)](http://badge.fury.io/js/engine.io-parser)
  6
  7This is the JavaScript parser for the engine.io protocol encoding,
  8shared by both
  9[engine.io-client](https://github.com/socketio/engine.io-client) and
 10[engine.io](https://github.com/socketio/engine.io).
 11
 12## How to use
 13
 14### Standalone
 15
 16The parser can encode/decode packets, payloads, and payloads as binary
 17with the following methods: `encodePacket`, `decodePacket`, `encodePayload`,
 18`decodePayload`, `encodePayloadAsBinary`, `decodePayloadAsBinary`.
 19
 20The browser-side parser also includes `encodePayloadAsArrayBuffer` and `encodePayloadAsBlob`.
 21
 22Example:
 23
 24```js
 25var parser = require('engine.io-parser');
 26
 27var data = new Buffer(5);
 28for (var i = 0; i < data.length; i++) { data[i] = i; }
 29
 30parser.encodePacket({ type: 'message', data: data }, function(encoded) {
 31  var decodedData = parser.decodePacket(encoded); // { type: 'message', data: data }
 32});
 33```
 34
 35### With browserify
 36
 37Engine.IO Parser is a commonjs module, which means you can include it by using
 38`require` on the browser and package using [browserify](http://browserify.org/):
 39
 401. install the parser package
 41
 42    ```shell
 43    npm install engine.io-parser
 44    ```
 45
 461. write your app code
 47
 48    ```js
 49    var parser = require('engine.io-parser');
 50
 51    var testBuffer = new Int8Array(10);
 52    for (var i = 0; i < testBuffer.length; i++) testBuffer[i] = i;
 53
 54    var packets = [{ type: 'message', data: testBuffer.buffer }, { type: 'message', data: 'hello' }];
 55
 56    parser.encodePayload(packets, function(encoded) {
 57      parser.decodePayload(encoded,
 58        function(packet, index, total) {
 59          var isLast = index + 1 == total;
 60          if (!isLast) {
 61            var buffer = new Int8Array(packet.data); // testBuffer
 62          } else {
 63            var message = packet.data; // 'hello'
 64          }
 65        });
 66    });
 67    ```
 68
 691. build your app bundle
 70
 71    ```bash
 72    $ browserify app.js > bundle.js
 73    ```
 74
 751. include on your page
 76
 77    ```html
 78    <script src="/path/to/bundle.js"></script>
 79    ```
 80
 81## Features
 82
 83- Runs on browser and node.js seamlessly
 84- Runs inside HTML5 WebWorker
 85- Can encode and decode packets
 86  - Encodes from/to ArrayBuffer or Blob when in browser, and Buffer or ArrayBuffer in Node
 87
 88## API
 89
 90Note: `cb(type)` means the type is a callback function that contains a parameter of type `type` when called.
 91
 92### Node
 93
 94- `encodePacket`
 95    - Encodes a packet.
 96    - **Parameters**
 97      - `Object`: the packet to encode, has `type` and `data`.
 98        - `data`: can be a `String`, `Number`, `Buffer`, `ArrayBuffer`
 99      - `Boolean`: optional, binary support
100      - `Function`: callback, returns the encoded packet (`cb(String)`)
101- `decodePacket`
102    - Decodes a packet. Data also available as an ArrayBuffer if requested.
103    - Returns data as `String` or (`Blob` on browser, `ArrayBuffer` on Node)
104    - **Parameters**
105      - `String` | `ArrayBuffer`: the packet to decode, has `type` and `data`
106      - `String`: optional, the binary type
107
108- `encodeBase64Packet`
109    - Encodes a packet with binary data in a base64 string (`String`)
110    - **Parameters**
111      - `Object`: the packet to encode, has `type` and `data`
112      - `Function`: callback, returns the base64 encoded message (`cb(String)`)
113- `decodeBase64Packet`
114    - Decodes a packet encoded in a base64 string.
115    - **Parameters**
116      - `String`: the base64 encoded message
117      - `String`: optional, the binary type
118
119- `encodePayload`
120    - Encodes multiple messages (payload).
121    - If any contents are binary, they will be encoded as base64 strings. Base64
122      encoded strings are marked with a b before the length specifier
123    - **Parameters**
124      - `Array`: an array of packets
125      - `Boolean`: optional, binary support
126      - `Function`: callback, returns the encoded payload (`cb(String)`)
127- `decodePayload`
128    - Decodes data when a payload is maybe expected. Possible binary contents are
129      decoded from their base64 representation.
130    - **Parameters**
131      - `String`: the payload
132      - `String`: optional, the binary type
133      - `Function`: callback, returns (cb(`Object`: packet, `Number`:packet index, `Number`:packet total))
134
135- `encodePayloadAsBinary`
136    - Encodes multiple messages (payload) as binary.
137    - **Parameters**
138      - `Array`: an array of packets
139      - `Function`: callback, returns the encoded payload (`cb(Buffer)`)
140- `decodePayloadAsBinary`
141    - Decodes data when a payload is maybe expected. Strings are decoded by
142      interpreting each byte as a key code for entries marked to start with 0. See
143      description of encodePayloadAsBinary.
144    - **Parameters**
145      - `Buffer`: the buffer
146      - `String`: optional, the binary type
147      - `Function`: callback, returns the decoded packet (`cb(Object)`)
148
149### Browser
150
151- `encodePayloadAsArrayBuffer`
152    - Encodes multiple messages (payload) as binary.
153    - **Parameters**
154      - `Array`: an array of packets
155      - `Function`: callback, returns the encoded payload (`cb(ArrayBuffer)`)
156- `encodePayloadAsBlob`
157    - Encodes multiple messages (payload) as blob.
158    - **Parameters**
159      - `Array`: an array of packets
160      - `Function`: callback, returns the encoded payload (`cb(Blob)`)
161
162## Tests
163
164Standalone tests can be run with `make test` which will run both node.js and browser tests.
165
166Browser tests are run using [zuul](https://github.com/defunctzombie/zuul).
167(You must have zuul setup with a saucelabs account.)
168
169You can run the tests locally using the following command:
170
171```
172./node_modules/.bin/zuul --local 8080 -- test/index.js
173```
174
175## Support
176
177The support channels for `engine.io-parser` are the same as `socket.io`:
178  - irc.freenode.net **#socket.io**
179  - [Google Groups](http://groups.google.com/group/socket_io)
180  - [Website](http://socket.io)
181
182## Development
183
184To contribute patches, run tests or benchmarks, make sure to clone the
185repository:
186
187```bash
188git clone git://github.com/LearnBoost/engine.io-parser.git
189```
190
191Then:
192
193```bash
194cd engine.io-parser
195npm install
196```
197
198See the `Tests` section above for how to run tests before submitting any patches.
199
200## License
201
202MIT