1# merge2 2 3Merge multiple streams into one stream in sequence or parallel. 4 5[![NPM version][npm-image]][npm-url] 6[![Build Status][travis-image]][travis-url] 7[![Downloads][downloads-image]][downloads-url] 8 9## Install 10 11Install with [npm](https://npmjs.org/package/merge2) 12 13```sh 14npm install merge2 15``` 16 17## Usage 18 19```js 20const gulp = require('gulp') 21const merge2 = require('merge2') 22const concat = require('gulp-concat') 23const minifyHtml = require('gulp-minify-html') 24const ngtemplate = require('gulp-ngtemplate') 25 26gulp.task('app-js', function () { 27 return merge2( 28 gulp.src('static/src/tpl/*.html') 29 .pipe(minifyHtml({empty: true})) 30 .pipe(ngtemplate({ 31 module: 'genTemplates', 32 standalone: true 33 }) 34 ), gulp.src([ 35 'static/src/js/app.js', 36 'static/src/js/locale_zh-cn.js', 37 'static/src/js/router.js', 38 'static/src/js/tools.js', 39 'static/src/js/services.js', 40 'static/src/js/filters.js', 41 'static/src/js/directives.js', 42 'static/src/js/controllers.js' 43 ]) 44 ) 45 .pipe(concat('app.js')) 46 .pipe(gulp.dest('static/dist/js/')) 47}) 48``` 49 50```js 51const stream = merge2([stream1, stream2], stream3, {end: false}) 52//... 53stream.add(stream4, stream5) 54//.. 55stream.end() 56``` 57 58```js 59// equal to merge2([stream1, stream2], stream3) 60const stream = merge2() 61stream.add([stream1, stream2]) 62stream.add(stream3) 63``` 64 65```js 66// merge order: 67// 1. merge `stream1`; 68// 2. merge `stream2` and `stream3` in parallel after `stream1` merged; 69// 3. merge 'stream4' after `stream2` and `stream3` merged; 70const stream = merge2(stream1, [stream2, stream3], stream4) 71 72// merge order: 73// 1. merge `stream5` and `stream6` in parallel after `stream4` merged; 74// 2. merge 'stream7' after `stream5` and `stream6` merged; 75stream.add([stream5, stream6], stream7) 76``` 77 78```js 79// nest merge 80// equal to merge2(stream1, stream2, stream6, stream3, [stream4, stream5]); 81const streamA = merge2(stream1, stream2) 82const streamB = merge2(stream3, [stream4, stream5]) 83const stream = merge2(streamA, streamB) 84streamA.add(stream6) 85``` 86 87## API 88 89```js 90const merge2 = require('merge2') 91``` 92 93### merge2() 94 95### merge2(options) 96 97### merge2(stream1, stream2, ..., streamN) 98 99### merge2(stream1, stream2, ..., streamN, options) 100 101### merge2(stream1, [stream2, stream3, ...], streamN, options) 102 103return a duplex stream (mergedStream). streams in array will be merged in parallel. 104 105### mergedStream.add(stream) 106 107### mergedStream.add(stream1, [stream2, stream3, ...], ...) 108 109return the mergedStream. 110 111### mergedStream.on('queueDrain', function() {}) 112 113It will emit 'queueDrain' when all streams merged. If you set `end === false` in options, this event give you a notice that should add more streams to merge or end the mergedStream. 114 115#### stream 116 117*option* 118Type: `Readable` or `Duplex` or `Transform` stream. 119 120#### options 121 122*option* 123Type: `Object`. 124 125* **end** - `Boolean` - if `end === false` then mergedStream will not be auto ended, you should end by yourself. **Default:** `undefined` 126 127* **pipeError** - `Boolean` - if `pipeError === true` then mergedStream will emit `error` event from source streams. **Default:** `undefined` 128 129* **objectMode** - `Boolean` . **Default:** `true` 130 131`objectMode` and other options(`highWaterMark`, `defaultEncoding` ...) is same as Node.js `Stream`. 132 133## License 134 135MIT © [Teambition](https://www.teambition.com) 136 137[npm-url]: https://npmjs.org/package/merge2 138[npm-image]: http://img.shields.io/npm/v/merge2.svg 139 140[travis-url]: https://travis-ci.org/teambition/merge2 141[travis-image]: http://img.shields.io/travis/teambition/merge2.svg 142 143[downloads-url]: https://npmjs.org/package/merge2 144[downloads-image]: http://img.shields.io/npm/dm/merge2.svg?style=flat-square 145