www.aleph1.co.uk Git - yaffs-website/blob - node_modules/onetime/readme.md

   1 # onetime [![Build Status](https://travis-ci.org/sindresorhus/onetime.svg?branch=master)](https://travis-ci.org/sindresorhus/onetime)
   2
   3 > Only call a function once
   4
   5 When called multiple times it will return the return value from the first call.
   6
   7 *Unlike the module [once](https://github.com/isaacs/once), this one isn't naughty extending `Function.prototype`.*
   8
   9
  10 ## Install
  11
  12 ```
  13 $ npm install --save onetime
  14 ```
  15
  16
  17 ## Usage
  18
  19 ```js
  20 let i = 0;
  21
  22 const foo = onetime(() => i++);
  23
  24 foo(); //=> 0
  25 foo(); //=> 0
  26 foo(); //=> 0
  27 ```
  28
  29
  30 ## API
  31
  32 ### onetime(function, [shouldThrow])
  33
  34 #### function
  35
  36 Type: `function`
  37
  38 Function that should only be called once.
  39
  40 #### shouldThrow
  41
  42 Type: `boolean`
  43 Default: `false`
  44
  45 ![](screenshot-shouldthrow.png)
  46
  47 Set to `true` if you want it to fail with a nice and descriptive error when called more than once.
  48
  49
  50 ## License
  51
  52 MIT © [Sindre Sorhus](http://sindresorhus.com)