Multi

Asynchronous execution library.

Features

• Run callbacks asynchronously in sequence or in parallel
• Wraps around an object with asynchronous methods
• Stops execution if error encountered
• Reusable call stack if needed

Installation

To install multi:

npm install multi

Install from git repository:

git clone https://github.com/derdesign/multi.git

Running tests:

make test

Usage

Multi creates a wrapper object containing the same methods as the original object. The wrapped methods can then be run either in sequence or in parallel, by providing the proper options to the Multi::exec method.

The following example wraps the fs module in a Multi object, to perform async file operations:

var fs = require('fs');
var Multi = require('multi');
  
var mfs = new Multi(fs);
 
mfs.readFile('assets/hello.html', 'utf-8');
mfs.readdir('assets/');
mfs.readFile('assets/style.css', 'utf-8');
mfs.lstat('assets/text.txt');
 
mfs.exec(function(err, results) {
  console.log(err || results);
});

API

Multi(options)

Multi constructor. Receives an options object. Available options are:

• parallel: Determines if the methods will run in parallel. Defaults to false

• interrupt: Interrupts execution if an error is encountered. Defaults to false

• flush: Clears the call stack after running exec. Defaults to true

multi.exec(callback)

Runs the wrapper methods asynchronously using the configuration passed to the multi constructor. The callback has a signature of (err, results). If an error occurs, err will be an array with the errors from the execution stack.

The results object is an array containing the arguments provided to callbacks in the execution stack.

Events

pre_exec: Emitted before running the call stack

post_exec: Emitted upon completion, before calling the exec callback

License

multi is MIT Licensed