Fredrik Normén

I have educated over 1000 developers the last 1 1/2 year and about 5% of them raise their hands when I ask them if they writes test, like unit test or if they use Test Driven Development (TDD). 5%! That is not much. When I asked them why they didn't write any tests, the answer is often, we should but don't have time to do it, some answer "we have test but no one maintain the test and update them".

During the age of the Windows DNA, most of us developers used COM/COM+ and a 3-tier architecture. Where we separate concerns by placing the views to present data into a layer called PL (Presentation Layer), we add all business logic into one single layer called BLL (Business Logic Layer), all code that handle data access was also placed into its own layer called DAL (Data Access Layer). During this time when Windows DNA was a hot topic, most application used this architecture.





By using DCOM it was easy to distribute the different components in the layers into distinct tiers. DCOM had its advantage and also disadvantage (DCOM hides the "distribution" and distribution could be done after application was written without the developers awareness, most applications wasn't designed for distribution purpose.). There was few application I was involved with that used DCOM, and I will in this article focus on the application that didn't use DCOM. The 3-tier architecture was well defined and common used. Several applications today used this architecture. When .Net arrived several developers was scratching their heads, it was a whole new platform for most of them and a difficult and confused time began, "how should this 3-tier architecture be applied on the .Net platform?". Web Services was introduced somewhere around this time and that was a bright light for some solution architects and developers, now they understand how to apply the 3-tier architecture on the .Net platform, the answer was to replace COM/COM+ components with Web Services. So instead of using a binary standard for the communication, XML and HTTP was used.

A friend of mine had a question about IList<T> and List<T>. He had noticed that some developers are returning IList<T> from methods, for example:

There is a discussion on the net about LINQ to SQL and if it should be removed in the future. My collogue and friend Patrik Löwendahl wrote a post about what he think, you can read about it here. I don't care if LINQ to SQL will be removed, honestly I want it to be removed. As Patrik wrote in his blog post, it's not the ADO.Net Team that created the LINQ to SQL. I think the team that focus on data access etc should be the team that build data access framework and the ADO.Net Team are doing a great job. After watching a session in the PDC about EF in the future, I must say that I will not use nHibernate or other OR-mapper as I have mention before in some old posts, I will now use EF. If we compare LINQ to SQL today with the current version of EF, LINQ to SQL is best suited for RAD, but in the future even EF will be suited for RAD. What I don't like with LINQ to SQL, is that developers are using the database first approached, they generate a model out from a database schema. A database is not object oriented.

We are some Swedish developer blogging live from PDC 2008 in Los Angeles on http://blog.pellesoft.se (All posts are written in Swedish).

Michel T. Nygard wrote the following in his book Release It!: "Sessions are the Achilles heel of a Web application."

The last three weeks I have visit several companies and talked about writing good code. It's amazing to see how different developer thinks about writing good code. Here are some comments when I asked if it's important to write good code:

I will attend the PDC 2008 this year, only two weeks left.. I hope see as many of you as possible at the conference.