I was introduced to the Microsoft Application Blocks around the time of .NET version 1.1 with the data application block. It does the heavy lifting for you, with all code written according to Microsoft .NET recommendations, and it greatly simplifies interacting with data backend (SQL Server in my case).
Since its inception, it has evolved into the Microsoft Enterprise Library, which includes more features on top of data access. This tour of the library's offerings focuses on recent changes that allow you to contribute to its continuing evolution. I'll begin with an overview of what comprises the Microsoft Enterprise Library and why you should care about it.
The main goal of the Microsoft Enterprise Library is to address common software needs. It meets this goal by offering reusable software components to assist with building .NET applications.
The library is comprised of eight application blocks:
- Data Access simplifies working with an underlining database while providing methods for performing common tasks like calling stored procedures.
- Exception Handling provides a framework for centralizing exception handling, making it easier to manage exceptions. This application block provides implementations for handling standard exceptions and for creating custom variations.
- Logging provides everything necessary to create log entries in various locations. Like the other application blocks, it allows you to centralize the functionality and thus spend your time coding application functionality as opposed to standard, repeatable operations like logging.
- Policy Injection assists with implementing Aspect Oriented Programming techniques within your code. This is achieved by intercepting method calls and invoking handlers before and after those methods based on configuration information.
- Semantic Logging facilitates using strongly-typed logging (aka semantic) within your application. This provides a more consistent and standard approach to logging, which is beneficial when processing the log data.
- Transient Fault Handling: Code-named Topaz, it can be used to add support for handling transient faults to your code. These type of faults occur infrequently and often disappear after a few retries. A good example is network issues hampering connecting to a web service.
- Unity provides a dependency injection container to be used with your code.
- Validation provides validation routines for common application functions. This includes user interface adapters for ASP.NET controls.
I have used the Data Access, Exception Handling, and Logging application blocks extensively, as these are base functions that are needed in most of my applications. I can pop these thoroughly tested components into my code and move on to more important tasks. There is no need to worry with these application blocks about the code working, though it does take time to become acclimated to using them in code.
Recent changes to the Microsoft Enterprise Library split it into 10 individual code repositories. This includes one for each application block listed above, individual repositories for the common infrastructure (used by all of the application blocks), and one for reference implementations. These repositories are hosted on CodePlex. Each application block has been stripped of dependencies, so they can live and breathe independently.
Throw in your two cents
Another recent change to the Microsoft Enterprise Library is a move to what they're calling an Open Development Model. It's not official open source, but it does open up the library and allow the community to drive changes and improvements. Learn how to contribute to one or more of the projects. Project and coding guidelines shed light on creating code and working with the project. The projects use Git for source code management.
Two goals of this change are more transparency with what is going on and consistency with how things are done (standards are published for Microsoft and external developers). To facilitate the transparency and consistency, each project or CodePlex site has its own backlog (issues and feature requests) and discussion forums.
A quick scan of the discussion forum for a couple projects doesn't show much activity, but then again, the projects were only set up about a week ago. There are some interesting discussions within the discussion forum for the main Enterprise Library project.
Take a closer look
The Open Development Model is a more open approach to the development to these tools. I'm not sure I'll have the chance to contribute to the projects, but the opportunity to get a closer look at the code created by Microsoft and how the company drives the projects is definitely a learning opportunity.
Using Git is great for managing the code, but you can easily take a stroll through the source code of your browser, as Figure A demonstrates with the ConnectionString class selected.
Browsing the ConnectionString class code in the Data Access Application Block
Be more productive
There are a lot of application blocks, so it can be overwhelming when you first confront them. Each block has its own application, so just focus on the one (or ones) that fit your needs. There are a number of resources about using the Microsoft Enterprise Library, including Hands-on Labs and the Developer's Guide. Also, the downloads section of the CodePlex projects contain valuable information.
In the end, the application blocks are straightforward to use, and the result is applications with standard and consistent features — after all, nobody wants or needs to reinvent the wheel. The application blocks lets you to focus on the more important code for your project.
Tony Patton has worn many hats over his 15+ years in the IT industry while witnessing many technologies come and go. He currently focuses on .NET and Web Development while trying to grasp the many facets of supporting such technologies in a production environment on a daily basis.