This is an interesting webcast on Channel9 where Eric Schmidt provides a technical tour of the NBCOlympics.com site built with Silverlight. If you are like me and become frustrated with the limited options of events the stations choose to broadcast, then we are in luck. The video that the NBCOlympics.com site is providing is excellent and covers nearly all the sports. I have heard estimates of roughly 2,200 hours of video, live commentary, live events, and with the ability to choose what we prefer to view. For those events we miss, we can search and view them at our leisure.

I have been able to watch some events I have always wanted to see but the television stations do not televise. Popularity and advertising dollars demand that stations air the usual suspects, swimming, track and field, gymnastics, ect. I have been able to explore fencing, sailing, handball, archery, and weightlifting to name a few.

If interested, check it out. If you have not seen the U.S. Men's 4x100 freestyle relay, check it out. What a race!

I was in a design discussion today and mentioned the need for a singleton object in our solution. Further along in the discussion I was trying to find a word that describes the opposite of a singleton, but alas, I struggled to find a word that may or may not exist. I just referred to the inverse object as a "new object." As I pondered this later in the day, I considered adjectives describing the nature of objects. They can be many things, but two concepts that popped into my head to classify them were "complex" and "simple."

I started playing with the words and making them resemble singleton. "Complexton" did not sound right to me. I should mention that I was washing my hands as I was contemplating this. I lifted up my head, looked into the mirror, and thought, "SIMPLETON." The opposite of a singleton is a "simpleton."

If the opposite of a singleton is not a "simpleton," then what is it? Until I find a plausible answer, I will try and insert this new term into my next design discussion.

Duplicate code to me is wrong. Writing duplicate code to me is like using poor grammar. If I am unaware of it, I am none the wiser. However, if I knowingly use poor grammar or duplicate code, I feel bad.

After seeing too many duplications across methods in one or more classes, I decided to investigate a way to remove these. I am always looking to remove duplicate code, even code that shares similarities, I look to refator. Removing duplications is important to adapt more easily to change. When a code change is required, we should only have to make it in one place. The following article will show two relatively simple means to address this code smell, delegates and an Aspect-Oriented approach.

The example I am using in this article is seen below. It is a unit test class, StackFixture class, and it is extremely trivial. This is a typical unit test taken from Test-Driven Development in Microsoft .NET. I have added the logging functionality as an easy means to show how these types of DRY violations can occur. While the duplications in this example deal with logging, they could pertain to other, more complex, functionality as well. The approaches to removing duplications across methods in this article can work with these simple scenarios, as well as more complex ones.

Take for example this sample test case. Each test method logs a message before and after executing the test logic. This violates DRY. We want to keep our test logic in our method, but factor out the duplicate logging. Again, if we were not logging, but doing some repetitive logic, we could factor that out as well.

   1: [TestFixture]

   2: public class StackFixture : AbstractBaseFixture

   3: {

   4:     private Stack stack;

   5:  

   6:     [SetUp]

   7:     public void SetUp()

   8:     {

   9:         stack = new Stack();

  10:     }

  11:  

  12:     [Test]

  13:     public void Empty()

  14:     {

  15:         Log.Info("Starting Empty test");

  16:  

  17:         Assert.IsTrue(stack.IsEmpty);

  18:  

  19:         Log.Info("Ending Empty test");

  20:     }

  21:  

  22:     [Test]

  23:     public void PushOne()

  24:     {

  25:         Log.Info("Starting PushOne test");

  26:  

  27:         stack.Push("first element");

  28:         Assert.IsFalse(stack.IsEmpty, "After Push, IsEmpty should be false.");

  29:  

  30:         Log.Info("Ending PushOne test");

  31:     }

  32:  

  33:     [Test]

  34:     public void Pop()

  35:     {

  36:         Log.Info("Starting Pop test");

  37:  

  38:         stack.Push("first element");

  39:         stack.Pop();

  40:         Assert.IsTrue(stack.IsEmpty, "After Push - Pop, IsEmpty should be true.");

  41:  

  42:         Log.Info("Ending Pop test");

  43:     }

  44:  

  45:     [Test]

  46:     [ExpectedException(typeof(InvalidOperationException))]

  47:     public void PopEmptyStack()

  48:     {

  49:         Log.Info("Starting PopEmptyStack test");

  50:  

  51:         stack.Pop();

  52:  

  53:         Log.Info("Ending PopEmptyStack test");

  54:     }

  55: }

Remove Duplications with Delegates

Quite simply, we can remove our method duplications using a delegate, in this case, the System.Action delegate. Thanks to Ayende for helping me understand this option. We create a method, TestMethod (as shown below), and add it to our StackFixture class. The method takes two strings (string beforeMessage and string afterMessage) and the Action delegate, representing the test method logic. We will call this method within our test cases.

   1: public void TestMethod(string beforeMessage, string afterMessage, Action action)

   2: {

   3:     // before

   4:     Log.Info(beforeMessage);

   5:     

   6:     // invoke our method

   7:     action();

   8:     

   9:     // after

  10:     Log.Info(afterMessage);

  11: }

Then, in our tests, we replace the following test method...

   1: [Test]

   2: public void Pop()

   3: {

   4:     Log.Info("Starting Pop test");

   5:  

   6:     stack.Push("first element");

   7:     stack.Pop();

   8:     Assert.IsTrue(stack.IsEmpty, "After Push - Pop, IsEmpty should be true.");

   9:  

  10:     Log.Info("Ending Pop test");

  11: }

With the same method using our delegate approach.

   1: [Test]

   2: public void Pop()

   3: {

   4:     TestMethod("Starting Pop test", "Ending Pop test",

   5:                delegate

   6:                    {

   7:                        stack.Push("first element");

   8:                        stack.Pop();

   9:                        Assert.IsTrue(stack.IsEmpty, "After Push - Pop, IsEmpty should be true.");

  10:                    });

  11: }

We can replace each of our test methods with the same TestMethod using the System.Action delegate. It will then easy to omit our before and after strings replacing them with "action.Method.Name," or some other intelligent logic to determine what to log.

This approach works well, but delegates are often difficult to understand. If this solution suits your needs, make sure the implementation is easily maintainable. What is nice about this approach is how simple it is. There is no need to reference any assemblies outside of the .Net framework, i.e. no third party dependencies.

The Aspect-Oriented Approach

Aspect-Oriented Programming (AOP) is an entirely different animal. It certainly deserves more than just a blog post. Please read more about it online. This article will not explain the details of AOP.

If you are reading this, welcome back. I will assume you are now familiar with AOP. There are several options for AOP frameworks. Some frameworks I have used are Spring.net, Castle Project, and PostSharp. The former two provide IoC capabilities as well. I suggest using a well-supported framework, one with community support and frequent updates. Investigate for yourself, there are several nice options available.

AOP with Castle DynamicProxy

Hamilton Verissimo put together a good sample using Castle's DynamicProxy. It is a nice, clean implementation.This worked fine for me and would work well in other situations. However, in my scenario, if I were to use this approach, I needed to have each of my test classes extend from MarshalByRef. In addition, I would need to modify the underlying NUnit framework to create my proxies in order to provide advice. Since I could not do the latter, or did not want to investigate, I searched for other AOP options.

The DynamicProxy aproach to solving your AOP needs is a great option. It just did not work in my situation, only because NUnit executes each of my methods. I would need to somehow intercept the creation of my test class, create a proxy of it, and execute the test methods on it.

AOP with PostSharp

Gael Fraiteur's PostSharp is a great option for AOP needs. It is extremely clean and easy to use. It is the simplest AOP framework I have used. I suggest watching Gael's video tutorial.

The first thing I needed to do, besides downloading and installing PostSharp, is to add two references to my project, PostSharp.Laos and PostSharp.Public. After that, I create a simple class extending OnMethodInvocationAspect, called LoggingMethodInvocationAspect.

   1: [Serializable]

   2: public sealed class LoggingMethodInvocationAspect : OnMethodInvocationAspect

   3: {

   4:     private ILogger log;

   5:  

   6:     public LoggingMethodInvocationAspect(ILogger logger)

   7:     {

   8:         log = logger;

   9:     {

  10:  

  11:     public override void OnInvocation(MethodInvocationEventArgs eventArgs)

  12:     {

  13:         // before

  14:         log.Info("OnInvocation Before proceed");

  15:  

  16:         // invoke

  17:         eventArgs.Proceed();

  18:  

  19:         // after

  20:         log.Info("OnInvocation After proceed");

  21:     }

  22: }

At this point, all we need to do is apply our aspect on target methods. The "AttributeTargetMembers" attribute can use wildcards. This tells the AOP framework to only intercept those methods in the "MathService" class that start with "Test." Below is the sample where I specify the target assembly, target type (class or classes to intercept), and target methods to intercept. There are many features beyond what I am showing so do further investigation.

   1: [assembly: ClassLibrary.SampleInterfaces.LoggingMethodInvocationAspect(

   2:     AttributeTargetAssemblies = "ClassLibrary.UnitTesting.Sandbox",

   3:     AttributeTargetTypes = "ClassLibrary.UnitTesting.Sandbox.MathService", 

   4:     AttributeTargetMembers = "Test*")]

Finally, my StackFixture class now looks something like this. Notice that the duplicate logging logic is now removed and each test method is prefixed with "Test" in the method name. This is so that PostSharp can filter what methods to intercept.

   1: [assembly: ClassLibrary.SampleInterfaces.LoggingMethodInvocationAspect(

   2:   AttributeTargetAssemblies = "ClassLibrary.UnitTesting.Sandbox",

   3:   AttributeTargetTypes = "ClassLibrary.UnitTesting.Sandbox.MathService", 

   4:   AttributeTargetMembers = "Test*")]

   5:     

   6: [TestFixture]

   7: public class StackFixture

   8: {

   9:     private Stack stack;

  10:  

  11:     [SetUp]

  12:     public void SetUp()

  13:     {

  14:         stack = new Stack();

  15:     }

  16:  

  17:     [TearDown]

  18:     public void TearDown(){}

  19:  

  20:     [Test]

  21:     public void TestEmpty()

  22:     { 

  23:         Assert.IsTrue(stack.IsEmpty); 

  24:     }

  25:  

  26:     [Test]

  27:     public void TestPushOne()

  28:     {

  29:         stack.Push("first element");

  30:         Assert.IsFalse(stack.IsEmpty, "After Push, IsEmpty should be false.");

  31:     }

  32:  

  33:     [Test]

  34:     public void TestPop()

  35:     {

  36:         stack.Push("first element");

  37:         stack.Pop();

  38:         Assert.IsTrue(stack.IsEmpty, "After Push - Pop, IsEmpty should be true.");

  39:     }

  40:  

  41:     [Test]

  42:     [ExpectedException(typeof(InvalidOperationException))]

  43:     public void TestPopEmptyStack()

  44:     {

  45:         stack.Pop();

  46:     }

  47: } 

The end result, a StackFixture test class with duplicate logging logic removed. The PostSharp AOP framework post-processes the compiled assembly and inserts itself, easily providing points of interception.

The PostSharp approach does involve a third-party dependency, but I feel like it is cleaner than the delegate approach. Gael informed me future versions of PostSharp will provide a more configurable solution than adding the [assembly ...] reference for the aspects, perhaps an XML configuration option. This can be done today, but involves some work.

Whether you use delegates, AOP, or some other approach, remove duplicate code wherever possible. I am happy to use either approach in my projects. There are tradeoffs to either solution, so investigate for yourself.

It is nice to be able to apply the Vista themes and sidebar personalizations (eye candy) to a Longhorn environment. This site appears to be thorough on the topic of Converting your Windows 2008 Server to a Workstation.

This article got me started with enabling the "aero" theme, Windows Server 2008 "Aero Enabled" Workstation Edition.

While installing Notepad2 on my Longhorn box (WindowsServer2008) I ran into an issue with overwriting the original notepad due to a lack of permissions. I found Matt Berther's article which helped me understand what files needed to be overwritten for use in Vista. While I ran into similar problems in Vista, I did not write down my steps, so when it came time to rebuild my Longhorn development environment, I battled the same issues.

Vista and Longhorn both have increased security measures.  Overwriting a system file like notepad.exe is more involved. While I can see their need for this added security, I do find it annoying. Regardless of whether or not you are installing Notepad2, as in this article, or you just need to reassign ownership of a file in Vista or Windows Server 2008, I hope this article helps alleviate some of the pain.

In following the article on overwriting notepad.exe with notepad2.exe, I first came across the issue of granting full control rights for this file to my logged in user. Since I have had to figure this process out more than once now, I am deciding to document it, with wonderful screen-shots.

While granting full control to the administrator, I was alerted with the following dialog.

In order to overwrite a file, like notepad.exe, we need to give the administrator "Full control." In order to do this, we need to change ownership of the file from "TrustedInstaller" to "Administrators." TrustedInstaller, by default, has full control, while the admin account does not.

Right click the target file, click Properties.

Click on the security tab. You should see the "Administrators" account, by default, with read and execute permissions only.

Click on the "Administrators" account, seen above, then click on "Advanced" as pictured below.

Next, we need to select the account for which we wish to edit owner permissions. Select the "Owner" tab. We should see "TrustedInstaller" highlighted as the current owner.

Click the "Edit..." button to change the owner of the file. The owner settings dialog should appear. Select the "Administrators" account, and click "Apply." After clicking apply, there should be a prompt as shown below.

Finally, click "OK." Then click "OK" to close the owner dialog. Click "OK" to save and exit the "Advanced Security Settings for <YourFileName.extension>."

Next, we want to allow "Full control" for the admin account. After closing the last dialog, we should still see the properties dialog for our file (the original dialog view, the second screen-shot in this series). Select the "Administrators" account, and click "Edit."

Give our "Administrators" account full control by enabling the checkboxes.

When you click "Apply" to apply these changes, the following prompt should be displayed. Click "Yes" to apply these changes to to grant full control to the administrator account.

At this point, the ownership of this file should have changed from the default "TrustedInstaller," to the "Administrators" group. For me, I can now overwrite this notepad.exe file with the more useful notepad2.exe.

I hope this article helps. Until Vista and Longhorn become second-nature, I know I will be referencing this.

The NHibernate FAQ
Craig Neuwirt
Hibernating Rhinos

I had to disable Internet Explorer Enhanced Security Configuration for my Windows2008 VMs today. I just couldn't take it anymore. I have been warned. I understand its importance. I am still turning it off. Don't try this at home.

I am currently working in a new development environment, unlike any that I have used in the past. It is different for two reasons, magnitude of dependencies and build process. The warning I have been given is, "this is a complex beast with lots of stuff in it, and much can go wrong." That statement pretty much covers the magnitude of dependencies stuff. As for the build process, my first question asked was, "you mean we don't use 'Ctrl+Shift+B' (in Visual Studio)?" No, we build using a command-line style approach, outside of the IDE.

Due the dependencies and build process, I wanted to schedule nightly builds on my local machines. This was when I discovered Windows PowerShell. PowerShell uses the .NET CLR and the .NET framework to provide new tools and methods for administering Windows environments. While similar in some aspects as DOS, PowerShell is much more. It is a command-line shell and scripting language that allows administrators to use C#.

Each night I want to backup certain files, sync files, clean and build my projects for 32 and 64 bit systems, update my environment with dependency changes, and email myself the log files generated during this process. I am not a DOS command nor scripting guru, but I could figure this out with some time. With PowerShell, I can leverage my C# knowledge to do all these tasks in a short amount of time.

If you want more control over administering your environments and would like to use C#, check out PowerShell. There is a good amount of support and tutorials to help get started.

Trivial Examples

The following is a trivial example of how to connect to a SQL database, query the Employees table of the Northwind database, and write those results to the screen. The PowerShell scripting syntax can be seen below.

   1: $conn = New-Object System.Data.SqlClient.SqlConnection

   2: $conn.ConnectionString = "Data Source=.;Database=Northwind;"

   3: $cmdText = "SELECT TOP 10 * FROM EMPLOYEES"