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Problem definition

A few weeks ago i started a thread on the Appcelerator development network about remote routes. The thread got a bit of attention and ultimately meant different things to different people.

web 1.0 transformations

When I get in front of customers today that have an existing web solution in place, they tend to ask some simple questions:

• What do I have to do to implement a service in <backend framework>?
• I’ve already got a bunch of web services, can I use them as is?
• My website has a traditional web 1.0 implementation, will i have to throw away and start over?

Primary focus: cost to implement seems to be the main chasm for them to hurdle.

REST zealots

A bunch of the developers out there are jazzed about building RESTfull services to remotely expose an endpoint for integration. Re-using these endpoints is a natural fit for them and paramount to their needs.

Primary focus: A clean single place to define their services.

back end framework architects

Then there are the framework guys that are out there that have the need to add Appcelerator to extend their portfolio. Recently I helped out with implementing an Appcelerator service for grails. To facilitate the framework integration I write a similar service broker in grails much akin to what we have done for the other platforms. The controller would discover the Appcelerator services written in grails and then invoke them directly. The downside is that:

• grails developers like to integrate at the controller level and not the service level
• grails itself makes responding to and rendering JSON very easy
• grails already has routing and discovery built into the framework

Primary focus: not duplicating existing framework functionality in a way that is consistent with their architecture

Previous approaches

In the past I’ve prescribed a 4-tiered strategy for those that are out there that are interested in integrating their existing application using Appcelerator;

• create new Appcelerator-specific remote services that reuse existing code inline if possible
• use an ESB to route to your existing services
• use the app:http written by Mr. Hashemi as mash-up in the client
• do not use remote services, but allow Appcelerator to add richness to your application locally in the browser

Solution

Instead of writing remote services that are Appcelerator specific and restrictive, an implicit contract is adhered to. This means that back end services can be written in any language or platform so long as they are able to consume and render in an approved format (for example ‘application/json’).

Traditional

Here is a simple example for a traditional service.

class MyService < Appcelerator::Service
Service 'order.create.request', :create_order, 'order.create.response'
 
def create_order
order = Order.new(params["amount"])
order.save
{'success'=>true, 'id'=>order.id}
end
end

Using remote routes

And now we make use of controllers as well as remote routes. Here is the controller

class OrderController < ApplicationController
def create
order = Order.new(params["amount"])
order.save
respond_to do |format|
format.json { render :json => {:success => true, :id => order.id} }
end
end
end

And now in the client we include the following in our javascript (there are a ton of ways to implement this, but here is an example for now)

	$MQR('r:create.order.request','/order/create','post',
'r:create.order.response');

trade offs

Wrap up

Understanding the trade-offs for the different service routing opportunities should be considered when you architect your solution. At the core of it, Appcelerator provides you with options and leaves that decision up to you, empowering you to make that choice for yourself.

this blog has beeen cross-posted at http://www.appcelerant.com/appcelerator-remote-routes-for-service-integration.html

Technorati Tags: appcelerator, json, ria, soa

Tags: appcelerator, json, ria, soa

This entry was posted on Sunday, October 5th, 2008 at 5:57 pm and is filed under announcements. You can follow any responses to this entry through the RSS 2.0 feed. You can leave a response, or trackback from your own site.