DDD on the Web

Profiling Apps 1 of N: The MVC ActionLink by Hadi Hariri

2010-03-09T20:34:00Z

I’m starting a new series of blogs posts on profiling, where we’ll try and cover common bottlenecks and how to identify them in your applications. However, before delving deeper into the subject, let me make a small but important observation: Your bottleneck is probably not your for loop Now, replace that for loop with switch statement , an older version of some outdated algorithm that you feel needs optimizing, or that retched collection of classes that would perform better if you were...(read more)

Ubiquitous and unambiguous ? by pvanooijen

2010-03-07T16:45:00Z

My last musings on a observed misuse of ubiquitous language (UL) led to deeper comments than I had ever realized when writing the story down. To many a non native speaker ubiquitous is at first hearing a strange word, as far as I know it is not widely used outside the world of IT. The sounding reminds of (un-)ambiguous, a term often found in the same context. There is a relation between these two words and IMHO that was the heart of the comments and led me to take another dive into the idea of UL...(read more)

On Small Applications by Udi Dahan

2010-03-07T11:32:34Z

I hear this too often: “X sounds like a great pattern, but it’s overkill for small applications”. Many patterns have been subjected to this including (but not limited to): SOA, DDD, CQRS, ORM, etc. Often the statement is made by a person without experience in the given pattern (though possibly experienced in other patterns). Let’s [...] Read More......(read more)

The Biggest Driver For Domain Modeling Decisions by Michael Nichols

2010-03-07T06:45:00Z

I just read a post from fellow devlicio.us'er Billy McCafferty and was considering what influences my own solutions to these concerns (ie, repositories, data transfer, etc) now. There has been an abrupt shift/growth in my thinking this year in how I perceive my domain and how I interact with or scale it. CQRS, perceived by some as a shiny new toy, and the discussions it provokes has definitely contributed to the maturity of the project I have been on by increasing its quality and adaptability...(read more)

A Few Thoughts on DDD, DTOs, View Models, CQS, Repositories and Separation of Concerns by Billy McCafferty

2010-03-06T16:41:00Z

What I've loved most about developing an open-source project is the ideas that I get from others who look at the work and either A) validate ideas, B) suggest that something stinks, or C) call a royal WTF and force people (e.g., me) to explain ideas more fully. It's usually during these explanation attempts that light bulbs start to come on and ideas are refactored and become more substantiated (or at least more defendable). The S#arp Architecture forums have been a gold mine, IMO, for the...(read more)

Better Application Services and CQS using S#arp Architecture 1.0 Q3 2009 by Billy McCafferty

2010-03-05T18:47:00Z

Obviously, S#arp Architecture is the bee's knees when it comes to developing ASP.NET MVC applications. ;) But as a project evolves and gets larger, "out of the box" S#arp Architecture 1.0 guidance runs into a few pain points. Particularly, there's poor use of the application services layer, the separation between controllers and application services is not very clear, entity listing pages become performance bottlenecks as the domain model gets sizable, there is no command/query...(read more)

Message-Based Systems for Maintainable, Asynchronous Development by Billy McCafferty

2010-03-02T04:22:00Z

Preface (you know it’s good if there's a preface) In Architectural Paradigms of Robotic Control , a number of architectures were reviewed including deliberative, reactive, and hybrid architectures. Each of these exhibit a clean separation of concerns with layering and encapsulation of defined behaviors. When implemented, the various capabilities, such as planners and mobility controllers, are encapsulated into discrete components for better reusability and maintainability. A pivotal aspect...(read more)

MSpec Live Templates by Hadi Hariri

2010-03-01T15:07:00Z

If you’re using MSpec ( Machine.Specifications ), you’ve no doubt run into the verbosity of it. Here’s a typical specification in MSpec [ Subject ( "Registering as new a usergroup" )] public class when_requesting_registration_page { Establish context = () => { }; Because of = () => { }; It should_display_blank_registration_form = () => { }; } The code is usually divided into three areas, the Establish that defines the context, Because which is defined as the action...(read more)

Strengthening your domain: Aggregate Construction by Jimmy Bogard

2010-02-24T04:12:10Z

Our application complexity has hit its tipping point, and we decide to move past anemic domain models to rich, behavioral models. But what is this anemic domain model? Let’s look at Fowler’s definition, now over 6 years old: The basic symptom of an Anemic Domain Model is that at first blush it looks like the real thing. There are objects, many named after the nouns in the domain space, and these objects are connected with the rich relationships and structure that true domain models have...(read more)

Transferred feed by Goeleven Yves

2010-02-23T21:01:16Z

To all of my loyal subscribers welcome back. I’ve transferred my original feed to this blog. From now on I will be talking cloud computing though and will no longer focus on Domain Driven Design, there is enough content on that topic nowadays anyway. But if you’re interested in cloud, and particulary windows azure, stay tuned… [...] Read More......(read more)

CQRS, Task Based UIs, Event Sourcing agh! by Greg

2010-02-16T16:23:42Z

Many people have been getting confused over what CQRS is. They look at CQRS as being an architecture; it is not. CQRS is a very simple pattern that enables many opportunities for architecture that may otherwise not exist. CQRS is not eventual consistency, it is not eventing, it is not messaging, it is not having separated models for reading and writing, nor is it using event sourcing. I want to take a few paragraphs to describe first exactly what CQRS is and then how it relates to other patterns...(read more)

[ANN] DC ALT.NET: 2/24 - Getting the Right System with George Dinwiddie by Matthew.Podwysocki

2010-02-15T22:28:41Z

The next DC ALT.NET meeting is taking place on 2/24/2010 from 7-9PM. Stay tuned to the mailing list for more information as it becomes available. In this meeting, once again we have George Dinwiddie, to give a talk on talk in the language of the business and what tools along the way can help us. Below is a description of the event. We hope to see you there! This year we have a lot of great sessions in store including Mono, Domain Driven Design, Git and other DVCS for the ...(read more)

CI and Google App Engine, or “How to force your way in” by Kyle Baley

2010-02-15T17:20:23Z

If you’re the type that skips titles, we’re using Google App Engine in our project, mostly because it’s there. I jest. We’re using it because it’s scalable and high performance and reliable and whatever other reason you can think of that will keep me from having a boring debate on the difference between Google and Amazon and Microsoft. Along with Google App Engine, we’re also using TeamCity for our continuous integration server. And generally speaking, these are two very disparate topics. I.e. I...(read more)

cqrs for dummies – 1 of N – the query layer by John Nuechterlein

2010-02-10T05:09:12Z

Back to the fun stuff. Series link here . As a reminder of what I’m talking about, here’s the picture from Mark : What I’m going to be talking about is section #1 from Mark’s picture, and in particular, I’m going to going over a number of concepts including: The Reporting Store Eventual Consistency You don’t need your Domain Once you have one, why not more? “Reporting” doesn’t just mean Reporting One of the first things that I found difficult when learning about CQRS was the use of the term “Reporting...(read more)

Strengthening your domain: a primer by Jimmy Bogard

2010-02-04T02:41:42Z

Recently, I talked some about the idea of an intentionally anemic domain model, under the name of “ Persistence Model ”. While a Persistence Model is great for a large percentage of projects, you may eventually want to move more behavior into the domain. That doesn’t mean a bevy of domain services doing the actual work, however. A strong domain means that our objects become more behavioral, and less as solely data-holders. But before we get into some of the patterns, what are some...(read more)