SimpleESB

A simple ESB application that can be used for Application Integration. This ESB is simple and uses the concept(s) of an itineray which contains on-ramp(s), transform(s), off-ramp(s) and message events. An on-ramp is an entry point onto the bus, likewise an off-ramp is an exit point off of the bus. A transformation is the reorganization of the message that was received on the bus into a new format. Finally, a message event is used to link the itinerary artifacts together (on-ramp, off-ramp, transform). The following features are currently supported.

Features

• On-Ramps
  • File
  • Excel
  • Amazon SQS
• Off-Ramps
  • Debug
  • Http
  • Amazon SQS
• Transformations
  • JSON-to-JSON

Limitations

Currently the ESB is only designed to work with JSON data. All messages must be in a JSON format when they leave the on-ramp into the bus.

Sample Overview

The sample illustrates using the SimpleESB to transfer orders from a front end e-commerce website to a backend order fulfillment system.

Sample Itinerary

var SimpleESB = require('simpleesb');

var yourmap = require('../transforms/yourmap');

exports.itinerary = new SimpleESB.Itinerary()
	.OnRamp(
		new SimpleESB.OnRamps.SqsOnRamp()						
			.publishAs('onramp::test')
			.provider(SimpleESB.SqsClientProvider.autoConfigure())
			.queue('/054218599934/Test'))
	
	.Transform(
		new SimpleESB.TransformService()			
			.provider(yourmap.createMap())
			.subscribeTo('onramp::test')
			.publishAs('transformed::test'))	

	.OffRamp(
		new SimpleESB.OffRamps.HttpOffRamp()
			.subscribeTo('transformed::test')
			.HttpMethod('POST')
			.Destination('http://localhost:8080/test/publish')
		);

Sample Map

var SimpleESB = require('simpleesb');

var yourmap = function() {
	
	return new SimpleESB.JsonMap()
		.field('*', 'status', function(source){ return 'PENDING'; })
		.field('created_at', 'createdOn')
		.field('payment.po_number', 'masterOrderNumber')
		.field('shipping_address.street', 'shipAddress')
		.field('shipping_address.city', 'shipCity')
		.field('shipping_address.region', 'shipState')
		.field('shipping_address.postcode', 'shipPostalCode')
		.field('*', 'shipTo', function(source) { return source.shipping_address.firstname + ' ' + source.shipping_address.lastname; })
		.field('customer_email', 'shipEmail')
		.field('shipping_address.telephone', 'shipPhone')
		.field('', 'shipMethod')
		.field('customer_email', 'userEmail')
		.field('', 'facilityName')		
		
		.collection('items', 'details', 
				new SimpleESB.JsonMap()
					.field('discount_amount', 'discount')
					.field('row_total', 'lineTotal')
					.field('qty_ordered', 'quantity')
					.field('price', 'salePrice')
					.field('tax_amount', 'salesTax')
					.field('price', 'unitPrice')
					.field('sku', 'sku')
					);
};

module.exports.createMap = yourmap;

Notes: When mapping you typically supply a source field and a destination field. However, as you can see above you are also able to add a 3rd argument to specify a Javascript function to use when mapping the specified field. If you are using a Javascript function then you must specify an * in the source field. When mapping a collection you will use the keyword collection and supply another map to use on the collection.

Running

To run the Simple ESB you can simply add the following to your application startup routine.

	require('simpleesb').start();