www.aleph1.co.uk Git - yaffs-website/blob - node_modules/fork-stream/README.md

   1 fork-stream [![build status](https://travis-ci.org/deoxxa/fork-stream.png)](https://travis-ci.org/deoxxa/fork-stream)
   2 ===========
   3
   4 Fork a stream in multiple directions according to a function.
   5
   6 Overview
   7 --------
   8
   9 fork-stream basically gives you conditional branching for streams. You supply
  10 the logic, fork-stream supplies the streaming.
  11
  12 Super Quickstart
  13 ----------------
  14
  15 Code:
  16
  17 ```javascript
  18 var ForkStream = require("fork-stream");
  19
  20 var fork = new ForkStream({
  21   classifier: function classify(e, done) {
  22     return done(null, e.match(/[aeiou]/));
  23   },
  24 });
  25
  26 fork.a.on("data", console.log.bind(console, "vowels:"));
  27 fork.b.on("data", console.log.bind(console, "no vowels:"));
  28
  29 fork.write("hello");
  30 fork.write("zxcbzz");
  31 fork.write("ooooooo");
  32
  33 fork.end();
  34 ```
  35
  36 Output:
  37
  38 ```
  39 vowels: hello
  40 no vowels: zxcbzz
  41 vowels: ooooooo
  42 ```
  43
  44 Installation
  45 ------------
  46
  47 Available via [npm](http://npmjs.org/):
  48
  49 > $ npm install fork-stream
  50
  51 Or via git:
  52
  53 > $ git clone git://github.com/deoxxa/fork-stream.git node_modules/fork-stream
  54
  55 API
  56 ---
  57
  58 **constructor**
  59
  60 Creates a new fork-stream.
  61
  62 ```javascript
  63 new ForkStream(options);
  64 ```
  65
  66 ```javascript
  67 var fork = new ForkStream({
  68   highWaterMark: 5,
  69   classifier: function(e, done) {
  70     return done(null, !!e);
  71   },
  72 });
  73 ```
  74
  75 * _options_ - regular stream options, and a `classifier` property that
  76   fork-stream will use to decide what output stream to send your object down.
  77
  78 Example
  79 -------
  80
  81 Also see [example.js](https://github.com/deoxxa/fork-stream/blob/master/example.js).
  82
  83 ```javascript
  84 var ForkStream = require("fork-stream");
  85
  86 var fork = new ForkStream({
  87   classifier: function classify(e, done) {
  88     return done(null, e >= 5);
  89   },
  90 });
  91
  92 fork.a.on("data", console.log.bind(null, "a"));
  93 fork.b.on("data", console.log.bind(null, "b"));
  94
  95 for (var i=0;i<20;++i) {
  96   fork.write(Math.round(Math.random() * 10));
  97 }
  98 ```
  99
 100 Output:
 101
 102 ```
 103 b 1
 104 a 6
 105 a 9
 106 a 10
 107 a 7
 108 a 5
 109 b 2
 110 b 4
 111 a 8
 112 b 3
 113 a 5
 114 b 4
 115 a 7
 116 a 8
 117 b 1
 118 a 6
 119 b 2
 120 b 0
 121 a 5
 122 b 1
 123 ```
 124
 125 License
 126 -------
 127
 128 3-clause BSD. A copy is included with the source.
 129
 130 Contact
 131 -------
 132
 133 * GitHub ([deoxxa](http://github.com/deoxxa))
 134 * Twitter ([@deoxxa](http://twitter.com/deoxxa))
 135 * Email ([deoxxa@fknsrs.biz](mailto:deoxxa@fknsrs.biz))