Limit your abstractionsSo what is the whole big deal about?

time to read 3 min | 453 words

When I started out, I pointed out that I truly dislike this type of architecture:


And I said that I much rather an architecture that has a far more limited set of abstractions, and I gave this example:

  1. Controllers
  3. Entities
  4. Commands
  5. Tasks
  6. Events
  7. Queries

That is all nice in theory, but let us talk in practice, shall we? How do we actually write code that actually uses this model?

Let us show some code that uses this type of code, this type, this is from the C# port of the same codebase, available here.

public class CargoAdminController : BaseController
  public ActionResult Register(
      [ModelBinder(typeof (RegistrationCommandBinder))] RegistrationCommand registrationCommand)
      DateTime arrivalDeadlineDateTime = DateTime.ParseExact(registrationCommand.ArrivalDeadline, RegisterDateFormat,

      string trackingId = BookingServiceFacade.BookNewCargo(
          registrationCommand.OriginUnlocode, registrationCommand.DestinationUnlocode, arrivalDeadlineDateTime

      return RedirectToAction(ShowActionName, new RouteValueDictionary(new {trackingId}));

Does this looks good to you? Here is what is actually going on here.


You can click on this link look at what is going in here (and I removed some stuff for clarity’s sake.

This stuff is complex, more to the point, it doesn’t read naturally, it is hard to make a change without modifying a lot of code. This is scary.

We have a lot of abstractions here, services and repositories and facades and what not. (Mind, each of those thing is an independent abstraction, not a common one.)

In my next post, I’ll show how to refactor this to a much saner model.

More posts in "Limit your abstractions" series:

  1. (22 Feb 2012) And how do you handle testing?
  2. (21 Feb 2012) The key is in the infrastructure…
  3. (20 Feb 2012) Refactoring toward reduced abstractions
  4. (16 Feb 2012) So what is the whole big deal about?
  5. (15 Feb 2012) All cookies looks the same to the cookie cutter
  6. (14 Feb 2012) Commands vs. Tasks, did you forget the workflow?
  7. (13 Feb 2012) You only get six to a dozen in the entire app
  8. (10 Feb 2012) Application Events–event processing and RX
  9. (09 Feb 2012) Application Events–Proposed Solution #2–Cohesion
  10. (07 Feb 2012) Application Events–Proposed Solution #1
  11. (06 Feb 2012) Application Events–what about change?
  12. (03 Feb 2012) Application Events–the wrong way
  13. (02 Feb 2012) Analyzing a DDD application