https://github.com/shinnn/optback.js

Extract options and a callback function from arguments
https://github.com/shinnn/optback.js

Last synced: 26 days ago
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Extract options and a callback function from arguments

• Host: GitHub
• URL: https://github.com/shinnn/optback.js
• Owner: shinnn
• License: mit
• Created: 2014-09-02T10:07:18.000Z (about 10 years ago)
• Default Branch: master
• Last Pushed: 2014-09-02T23:38:29.000Z (about 10 years ago)
• Last Synced: 2024-09-25T14:44:41.270Z (about 2 months ago)
• Language: JavaScript
• Size: 129 KB
• Stars: 2
• Watchers: 1
• Forks: 0
• Open Issues: 0
• Metadata Files:
  • Readme: README.md
  • License: LICENSE

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README

        
# optback.js

[![Build Status](https://travis-ci.org/shinnn/optback.js.svg?branch=master)](https://travis-ci.org/shinnn/optback.js)

[![Build status](https://ci.appveyor.com/api/projects/status/4oob8xymj0m3bg16)](https://ci.appveyor.com/project/ShinnosukeWatanabe/optback-js)

[![Coverage Status](https://img.shields.io/coveralls/shinnn/optback.js.svg)](https://coveralls.io/r/shinnn/optback.js)

[![devDependency Status](https://david-dm.org/shinnn/optback.js/dev-status.svg)](https://david-dm.org/shinnn/optback.js#info=devDependencies)

Extract options and a callback function from arguments

```javascript

optback(['foo', {bar: 'baz'}, function qux() {/* ... */}]);

/*

=> {

      options: {bar: 'baz'},

      callback: [Function: qux]

   }

*/

```

This module is useful to create a function which takes an option object  and a callback function as its arguments, like [Node](http://nodejs.org/)'s [`fs.readFile`](http://nodejs.org/api/fs.html#fs_fs_readfile_filename_options_callback).

## Installation

### Package managers

### [npm](https://www.npmjs.org/) [![NPM version](https://badge.fury.io/js/optback.svg)](https://www.npmjs.org/package/optback)

```

npm install --save optback

```

### [bower](http://bower.io/) [![Bower version](https://badge.fury.io/bo/optback.svg)](https://github.com/shinnn/optback.js/releases)

```

bower install --save optback

```

### Standalone

[Download the script file directly.](https://raw.githubusercontent.com/shinnn/optback.js/master/optback.js)

## API

### optback(*args*)

*args*: `Array` or [array-like object](https://www.inkling.com/read/javascript-definitive-guide-david-flanagan-6th/chapter-7/array-like-objects) (e.g. [`arguments`](https://developer.mozilla.org/docs/Web/JavaScript/Reference/Functions_and_function_scope/arguments))  

Return: `Object`

It returns an object in the form `{options: [Object], callback: [Function]}`:

* `options` is the penultimate element of *args*, or `{}` if that is not an object.

* `callback` is the last element of *args*.

It throws an error when the last element is not a function.

```javascript

(function() {

  var argv = getCallback(arguments);

  argv.options; //=> {some: 'options'}

  argv.callback; //=> [Function: cb]

})('foo', {some: 'options'}, function cb() {/* ... */});

```

## License

Copyright (c) 2014 [Shinnosuke Watanabe](https://github.com/shinnn)

Licensed under [the MIT License](./LICENSE).