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1# EE First
2
3[![NPM version][npm-image]][npm-url]
4[![Build status][travis-image]][travis-url]
5[![Test coverage][coveralls-image]][coveralls-url]
6[![License][license-image]][license-url]
7[![Downloads][downloads-image]][downloads-url]
8[![Gittip][gittip-image]][gittip-url]
9
10Get the first event in a set of event emitters and event pairs,
11then clean up after itself.
12
13## Install
14
15```sh
16$ npm install ee-first
17```
18
19## API
20
21```js
22var first = require('ee-first')
23```
24
25### first(arr, listener)
26
27Invoke `listener` on the first event from the list specified in `arr`. `arr` is
28an array of arrays, with each array in the format `[ee, ...event]`. `listener`
29will be called only once, the first time any of the given events are emitted. If
30`error` is one of the listened events, then if that fires first, the `listener`
31will be given the `err` argument.
32
33The `listener` is invoked as `listener(err, ee, event, args)`, where `err` is the
34first argument emitted from an `error` event, if applicable; `ee` is the event
35emitter that fired; `event` is the string event name that fired; and `args` is an
36array of the arguments that were emitted on the event.
37
38```js
39var ee1 = new EventEmitter()
40var ee2 = new EventEmitter()
41
42first([
43 [ee1, 'close', 'end', 'error'],
44 [ee2, 'error']
45], function (err, ee, event, args) {
46 // listener invoked
47})
48```
49
50#### .cancel()
51
52The group of listeners can be cancelled before being invoked and have all the event
53listeners removed from the underlying event emitters.
54
55```js
56var thunk = first([
57 [ee1, 'close', 'end', 'error'],
58 [ee2, 'error']
59], function (err, ee, event, args) {
60 // listener invoked
61})
62
63// cancel and clean up
64thunk.cancel()
65```
66
67[npm-image]: https://img.shields.io/npm/v/ee-first.svg?style=flat-square
68[npm-url]: https://npmjs.org/package/ee-first
69[github-tag]: http://img.shields.io/github/tag/jonathanong/ee-first.svg?style=flat-square
70[github-url]: https://github.com/jonathanong/ee-first/tags
71[travis-image]: https://img.shields.io/travis/jonathanong/ee-first.svg?style=flat-square
72[travis-url]: https://travis-ci.org/jonathanong/ee-first
73[coveralls-image]: https://img.shields.io/coveralls/jonathanong/ee-first.svg?style=flat-square
74[coveralls-url]: https://coveralls.io/r/jonathanong/ee-first?branch=master
75[license-image]: http://img.shields.io/npm/l/ee-first.svg?style=flat-square
76[license-url]: LICENSE.md
77[downloads-image]: http://img.shields.io/npm/dm/ee-first.svg?style=flat-square
78[downloads-url]: https://npmjs.org/package/ee-first
79[gittip-image]: https://img.shields.io/gittip/jonathanong.svg?style=flat-square
80[gittip-url]: https://www.gittip.com/jonathanong/