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  
10  Get the first event in a set of event emitters and event pairs,
11  then clean up after itself.
12  
13  ## Install
14  
15  ```sh
16  $ npm install ee-first
17  ```
18  
19  ## API
20  
21  ```js
22  var first = require('ee-first')
23  ```
24  
25  ### first(arr, listener)
26  
27  Invoke `listener` on the first event from the list specified in `arr`. `arr` is
28  an array of arrays, with each array in the format `[ee, ...event]`. `listener`
29  will 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`
31  will be given the `err` argument.
32  
33  The `listener` is invoked as `listener(err, ee, event, args)`, where `err` is the
34  first argument emitted from an `error` event, if applicable; `ee` is the event
35  emitter that fired; `event` is the string event name that fired; and `args` is an
36  array of the arguments that were emitted on the event.
37  
38  ```js
39  var ee1 = new EventEmitter()
40  var ee2 = new EventEmitter()
41  
42  first([
43    [ee1, 'close', 'end', 'error'],
44    [ee2, 'error']
45  ], function (err, ee, event, args) {
46    // listener invoked
47  })
48  ```
49  
50  #### .cancel()
51  
52  The group of listeners can be cancelled before being invoked and have all the event
53  listeners removed from the underlying event emitters.
54  
55  ```js
56  var 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
64  thunk.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/