lib-onion

Pipelining with early exit option. Similar to async.waterfall however with the ability to exit out of the waterfall at any point.

The key features are:

• The ability to exit out of the pipeline early, without error, by calling exit.
• Clear debugging ability as to which service is being executed with DEBUG=onion:*
• A dynamic number of arguments can flow down the pipeline, next and exit will just be appended to the end.

Getting Started

Install the module with: npm install lib-onion

From there, define your pipeline:

var Onion = require('lib-onion');
var onion = new Onion('my-onion');
 
onion.add(function(msg, next, exit) {
    msg.touchedByService1 = true;
    next(null, msg);
}, 'service1');
 
onion.add(function(msg, next, exit) {
    console.log(msg.touchedbyservice1); // === true
    exit(null, msg);
}, 'service2');
 
onion.add(function(msg, next, exit) {
    console.log('Ill never get called in this example');	
}, 'service3');
 

And finally, execute it:

onion.handle(yourInputObject, function(err, result) {
    console.log(result); // === true
});

There are a bunch more examples in the tests/ folder.

Contributing

In lieu of a formal styleguide, take care to maintain the existing coding style. Add unit tests for any new or changed functionality. Lint and test your code using Grunt.

Release History

0.1.0 Initial Release 0.1.1 Simplified the entry point

License

Copyright (c) 2015 Hewlett-Packard Licensed under the MIT license.