Thursday, September 20, 2007

Slightly slimmed down Cairngorm

Currently, I am in the finishing stages of a Flex 2 project (actually a pet project of mine and 2 buddies). We have chosen to use Cairngorm for the client-side architecture. Generally, I am quite happy with this choice because it saved us from having to re-invent the wheel and it works quite well for us.


At the beginning of the project we felt that Cairngorm introduces too much bureaucracy into our client-side architecture. It was simply too heavy for our needs (more like J2EE in 2001 than Ruby on Rails in 2007). So we stripped out two parts that we thought are adding unnecessary complications:

  • The most annoying bit for us were the value objects (VOs). We already have a model and we have an event object. We simply had no reason to create another object for transporting data. If we want to pass a model object to the business delegate we simply pass this model. I we want to pass some very simple set of variables (say, a string and an integer) we simply add that into the event. No need for VOs in our case.
  • We use only one business delegate. This delegate encapsulates all available services. To be honest, I am not sure if Cairngorm is even meant to be implemented like this, but anyway, it saves us from creating a new delegate whenever we add a service. All we need to do is add a new method to our delegate.
So adding a new service boils down to
  • adding a method in the delegate and the controller respectively
  • creating a new event class
  • creating a new responder/command class
Even coming from a RoR background where DRY is the dogma we can live with that.

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