Package Exports

extract-opts

This package does not declare an exports field, so the exports above have been automatically detected and optimized by JSPM instead. If any package subpath is missing, it is recommended to post an issue to the original package (extract-opts) to support the "exports" field. If that is not possible, create a JSPM override to customize the exports field for this package.

Readme

Extract Options & Callback

Extract the options and callback from a function's arguments easily

Install

NPM

Install: npm install --save extract-opts
Use: require('extract-opts')

Browserify

Install: npm install --save extract-opts
Use: require('extract-opts')
CDN URL: //wzrd.in/bundle/extract-opts@3.1.0

Ender

Install: ender add extract-opts
Use: require('extract-opts')

Usage

JavaScript

var extractOptsAndCallback = require('extract-opts')
var log = console.log.bind(console)

// fs.readFile(filename, [options], callback)
var readFile = function(filename, opts, next){
    // Extract options and callback
    var args = extractOptsAndCallback(opts, next)
    opts = args[0]
    next = args[1]

    // Forward for simplicities sake
    require('fs').readFile(filename, opts, next)
}

// Test it
readFile('package.json', log)          // works with no options
readFile('package.json', null, log)    // works with null options
readFile('package.json', {next:log})   // works with just options

CoffeeScript

extractOptsAndCallback = require('extract-opts')
log = console.log.bind(console)

# fs.readFile(filename, [options], callback)
readFile = (filename, opts, next) ->
    # Extract options and callback
    [opts, next] = extractOptsAndCallback(opts, next)

    # Forward for simplicities sake
    require('fs').readFile(filename, opts, next)

# Test it
readFile('package.json', log)          # works with no options
readFile('package.json', null, log)    # works with null options
readFile('package.json', {next:log})   # works with just options

Configuration

Extract Options and Callback also supports a third argument for custom configuration.

You can use this third argument to customize the completionCallbackNames property that defaults to ['next']. This is useful if your completion callback has other names besides next. Allowing you to do the following:

extractOptsAndCallback = (opts, next, config={}) ->
    config.completionCallbackNames ?= ['next', 'complete', 'done']
    return require('extract-opts')(opts, next, config)
log = console.log.bind(console)

# The readFile method as before

# Test it
readFile('package.json', {next:log})        # works the standard completion callback name
readFile('package.json', {complete:log})    # works with our custom compeltion callback name
readFile('package.json', {done:log})        # works with our custom compeltion callback name