Simple library to chain and run functions with asynchronous calls.

Via npm on Node:

npm install simpleasync

Reference in your program:

var async = require('simpleasync');

In the following samples, next is a function function (err, data)...

Define and run steps with data and then:

async()
    .data(10)
    .then(function (data, next) {
        console.log(data);
        next(null, data + 1);
    })
    .then(function (data, next) {
        console.log(data);
    });

Expected output

10
11

Use exec to inject asynchronous data:

async()
    .exec(function (next) { next(null, 10); })
    .then(function (data, next) {
        console.log(data);
        next(null, data + 1);
    })
    .then(function (data, next) {
        console.log(data);
    });

Expected output

10
11

Use error for catch errors:

async()
    .data(10)
    .then(function (data, next) {
        console.log(data);
        throw "Houston, we have a problem";
    })
    .error(function (err) {
        console.log('error:', err);
    });

Expected output

10
error: Houston, we have a problem

Raise an error in an step with callback

async()
    .data(10)
    .then(function (data, next) {
        console.log(data);
        next("Houston, we have a problem", null);
    })
    .error(function (err) {
        console.log('error:', err);
    })

Expected output

10
error: Houston, we have a problem

do function generate an element of an array, to be received by the next then or map in sequence:

async()
    .data(1)
    .do(function (data, next) { next(null, data + 1); })
    .do(function (data, next) { next(null, data + 2); })
    .do(function (data, next) { next(null, data + 3); })
    .then(function (data) {
        console.dir(data);
    });

Expected output

[ 2, 3, 4 ]

map take each element of the previous array and generate a new element

async()
    .data(1)
    .do(function (data, next) { next(null, data + 1); })
    .do(function (data, next) { next(null, data + 2); })
    .do(function (data, next) { next(null, data + 3); })
    .map(function (data, next) { next(null, data * 3); })
    .then(function (data) {
        console.dir(data);
    });

Expected output

[ 6, 9, 12 ]

The asynchronous functions accepted by a consecutive series of do are executed with concurrency. The data collected by the functions are assembled in an array, that is the data feeded into the next step.

git clone git://github.com/ajlopez/SimpleAsync.git
cd SimpleAsync
npm install
npm test

• map accepting async functions

TBD

• 0.0.1: Published
• 0.0.2: Published
• 0.0.3: Published. do with sync and async functions. map async function support
• 0.0.4: Published, fail function
• 0.0.5: Published, fix async map with empty array
• 0.0.6: Published, use setTimeout instead setImmediate
• 0.0.7: Published, improved do implementation, engine versions updated
• 0.0.8: Published, fail and run deprecated, new data method, removing support for sync functions, autorun, exec method to inject async data

MIT

Feel free to file issues and submit pull requests � contributions are welcome<

If you submit a pull request, please be sure to add or update corresponding test cases, and ensure that npm test continues to pass.