node-flow

Node.js utility to execute a sequence of asynchronous functions without getting into callback hell.

It has the good parts of async.waterfall and step put together !

good parts from step

• catches error thrown out by a step

good parts from async.waterfall

• keeps 'next' as explicit argument (not using this)
• receives an explicit error callback (no more if (err) return callback(err) in every step)
• halts the execution of remaining steps on error

installation

npm install node-flow 

example

var flow = require('node-flow');

function getThisDone(callback) {
	flow(callback,
		function one(next) {
			console.log('step one');
			next(null, 'cool');
		},
		function two(next,  msg) {
			console.log('step two: ', msg);
			next();
		},
		function three(next) {
			console.log('step three');
			next(null, 'wow');
		}
	);
}

getThisDone(function(err, result) {
	if (err) {
		console.log('oops! ', err);
	} else {
		console.log('result: ', result);
	}
});

NOTE

check out Co if you're running node.js with generator support