Achieving Programmer Productivity using a Reusable Framework and Code
This is good news. The promise of the .Net, programmer
productivity, can be achieved. After my most recent project
there is no doubt in my mind: .Net is the most productive
environment for application development that I've ever used.
The numbers are there to support this assertion. Let me tell
you how it works and then I'll show you some of the numbers at the
end of this article.
There are two factors behind the programmer productivity:
- The ease of building a reusable framework library through
object oriented techniques
- The ease of using code generation tools to build the
business object/data access layers of the application.
The project that I'm using as a reference has built three
applications in 8 months. Much of that time was spent on
building the WinForms framework that provides the foundation for the
applications. The business object layer provides an easily
bindable object library that takes care of all of the data access.
98 percent of the code in this library was generated. The rest
was written to enforce business rules.
Figure 1 illustrates the architecture employed on these projects.
As you can see, the application uses the business object library and
does not interact with the database directly. It also uses
various classes from the WinForms Application Framework (WFA) and
has few interactions with the operating system or even with the .Net
Figure 1: Architecture of the
WinForms Application Framework
Figure 2 shows where the code in the framework and business
libraries came from. It's a combination of hand written code,
libraries supplied by Microsoft in the form of application blocks,
and generated code. The WFA has its own set of business
objects that provide persistence of messages, security settings, and other objects that make up the framework.
Figure 2: Sources of WinForms
Application Framework Code
The business object libraries use the CSLA design created by
Rocky Lhotka and written about in his book
Expert One-on-One Visual Basic Business Objects. The code
generation tool is ComExpress. Shoutsoft, the maker of
ComExpress includes their own somewhat modified version of the CSLA
library that uses attributes on the business objects to dynamically
generate SQL for data access. It's an interesting approach and
one that I've been able to turn to my advantage. Using it I've
been able to create a CSLA library that access a DB2 database hosted
on a iSeries system. And I've been able to make objects that
are usually on DB2 work on SQL Server when the application is
offline and using a replicated database. I turns out to be
So where does the programmer productivity come from? As you
can see from Figure 2, the WFA Framework code has been written once
and used with several applications. We're on our third one
now. Like I said, the business objects were generated a
process that took several hours of design time for about 70 objects
using the code generation tool. At the bottom of the figure
are Microsoft Application Blocks that come from Microsoft's
Patterns and Practices web site and the CSLA code that came from
Rocky's book and from the ComExpress tool. Although the code
generation tool costs money. Rocky's version of CSLA is free (FYI,
CodeSmith has a free template for CLSA). At the absolute
bottom is the .Net Framework, which is part of the operating system.
The only code that has to be written for each new application is the
application it self.
Figure 3 shows the quantity of code that went to each of the
boxes above. I picked Application 1, which was the largest of
the three. As you can see, the application code makes up only
12% of the total code. K LoC stands for thousand lines of
Figure 3: Quantity of Code in Each
Finally, Figure 4 breaks the code down by how it was obtained.
Figure 4: Breakdown of the Code by
Method of Creation
Eighty-eight percent of the next application doesn't have to be
written by hand. Of course, there may be a need for new
business objects for the next application but the code generation
approach using CSLA takes care of that. What's more, because
there are so many tasks that are already handled by the WinForms
Application Framework, I can spend most of my time building the
application and, I hope, making it better.