simpleasync

SimpleAsync

Simple library to chain and run functions with asynchronous calls.

Installation

Via npm on Node:

npm install simpleasync

Usage

Reference in your program:

var async = require('simpleasync');

Define and run steps with then:

async()
    .then(function (data) {
        console.log(data);
        return data + 1;
    })
    .then(function (data) {
        console.log(data);
    })
    .run(10);

Expected output

10
11

Define and run steps with one step using a callback. Then, you can write async steps:

async()
    .then(function (data, next) {
        console.log(data);
        next(null, data + 1); // callback(err, newdata);
    })
    .then(function (data) {
        console.log(data);
    })
    .run(10);

Expected output

10
11

Use fail for catch errors:

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

Expected output

10
error: Houston, we have a problem

Raise an error in an step with callback

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

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()
    .do(function (data) { return data + 1; })
    .do(function (data) { return data + 2; })
    .do(function (data) { return data + 3; })
    .then(function (data) {
        console.dir(data);
    })
    .run(1);

Expected output

[ 2, 3, 4 ]

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

async()
    .do(function (data) { return data + 1; })
    .do(function (data) { return data + 2; })
    .do(function (data) { return data + 3; })
    .map(function (data) { return data * 3; })
    .then(function (data) {
        console.dir(data);
    })
    .run(1);

Expected output

[ 6, 9, 12 ]

do accepts function with callback:

async()
    .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) { return data * 3; })
    .then(function (data) {
        console.dir(data);
    })
    .run(1);

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. In the above example, the three async functions of do returned and array with

[ 2, 3, 4 ]

map accepts function with callback, too:

async()
    .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 * data); })
    .then(function (data) {
        console.dir(data);
    })
    .run(1);

Expected output

[ 4, 9, 16 ]

Development

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

To do

• map accepting async functions

Samples

TBD

Versions

• 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

License

MIT

References

Contribution

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.