I’ve been a big fan of Resharper for quite a while, and I’ve heard a few people comment on how cool the structured search and replace is. Two weeks into my new assignment at N4 Solutions, I had a need to change some code that I thought structured search and replace would be ideal for. Given some code structured like that shown below:

[DataContract]
public class Foo
{
    [DataMember(IsRequired = true)]
    public IList Bars { get; set; }
}

I want to replace all public properties so that when they are required (i.e., the DataMember attribute has an IsRequired property set to true), I want the property to become read-only by making the set protected. So the above example would become:

[DataContract]
public class Foo
{
    [DataMember(IsRequired = true)]
    public IList Bars { get; protected set; }
}

Sounds straight forward, and you can see why I thought structured search and replace would be the ideal tool for this job. After all, this is a straight forward mechanical task – when IsRequired is true, make the setter protected. Simple. Although Resharper’s structural search and replace appears to be a fantastic feature, it doesn’t appear to support this kind of “structure”. It works fine across expressions and statements, but not if you want to work at method, property, attribute, or class levels. It doesn’t appear to support those, giving you the “Cannot parse pattern” error. If the team at JetBrains read this, then please work on supporting these structures too – it would make an awesome feature even more awesome.

Wow, has it really been another year since my last blog post?

I travelled up to Birmingham Science Park today and attended my first Open Space Coding Day, with the focus of the day being on Windows Azure. The format of the day was a new experience and completely different to what I have typically found at user-group sessions or a training course. The aim of the day is for everyone to learn from each other, rather than sitting through a rehearsed presentation of slides and demo code. Essentially, once the attendees have suggested, voted and scheduled a collection of topics for the day, they split up into groups who then collectively research that topic, or undertake a hands-on coding exercise together.

In all, there were around 40 attendees, and I think that with exception to a few, most of us were all Azure newbies. Microsoft was well represented, and in particular Eric Nelson and David Gristwood were available throughout the day to help out with the groups, and for answering everyone’s questions.

SQL Azure appeared to be the most popular topic, but for my part I wanted to remain more focused on the compute aspects of Azure. After deploying my first WebRole into the cloud (via the free service instances that were arranged for the attendees by Microsoft), I started developing a Distributed Grep solution made up of Worker Roles, WCF services and Queues. Obviously I hadn’t completed this by the end of the day – after all, I was there to learn, but I am planning on finishing this little pet-project, and I’ll hopefully contribute the code to the OpenSpaceCode Repository as soon as I can. In the meantime I’ll be frequently checking out the UK Azure Platform online-community (available on Ning) for future events, and to keep up to date with what others are learning and discovering and what they are building on the Azure platform.

If you’re using jQuery and want to improve the user-experience on your website, then take some time over a coffee and read this article.

It outlines more than 45 jQuery based solutions to improving website user-experience, including iPod style drilldown menus, Facebook like dynamic input, context menus, pagination, and light-box techniques.

Mocking Frameworks are becoming more prominent in our development activities as unit testing, and hopefully test driven development, become much more mainstream. Like most technical topics, the choice of Mocking Framework can lead to long debates. I’ve been involved in these debates myself, and a fairly recent Phil Haack post that compares Rhino Mocks to Moq sums up these typical discussions.

Like Phil (and I would suspect most other Developers), I too have only recently discovered Moq (pronounced “mock-you”), and I’ve started to favour it over Rhino Mocks. Expectations are much more easily set up, and playback is more implicit. This simply suits my style and I also like the use of lambda’s in setting up the expectations. Perhaps my style makes me a mockist.

I accidentally came across this blog post yesterday that discusses the use of explicit and implicit interface implementations in C#. I have to admit, although I’ve known about these two approaches of interface implementation, I’ve never really given them any serious thought. I normally implement interfaces implicitly:

public interface IFoo
{
   void Bar();
}

public class Foo : IFoo
{
   public void Bar()
   {
      // implementation
   }
}

The explicit version basically requires that you qualify the method in the implementing type (IFoo.Bar()), and remove the access modifier (since it must be public as in the interface itself). So far the only changes are in the syntax, therefore the differences must manifest themselves during compilation:

Given the explicit implementation of IFoo:

public class Foo : IFoo
{
   void IFoo.Bar()
   {
      // implementation
   }
}

you cannot directly invoke Bar() on a Foo object without first casting it to IFoo:

Foo f = new Foo();
f.Bar(); // causes a compilation error

Foo f = new Foo();
((IFoo)f).Bar(); // works fine

In my opinion (coming from a C++ background), this is counter-intuitive. Since the Bar() method is public I would like it to be callable without a cast. After all, there is nothing stopping me from performing the cast in order to call the method, so why does the compiler force you through the hoops?

Brad Adams has some interesting thoughts on explicit interface implementations and where they should be used. In brief, he recommends their usage for hiding implementation details (i.e., the interface is typically only used internally), therefore approximating a private interface implementation. As I already mentioned, you can still directly call the methods through a cast, but the methods are effectively hidden from public view. Given this, I would generally think of explicit interface implementation as an implementation pattern, and I feel safe continuing to implement interfaces implicitly.

One final thought: if you use explicit interface implementation on a value type (i.e., on a struct), there will be a boxing performance penalty when you call any of the implemented methods.

As Developers we have quickly learnt how important unit testing is. Moreover we have also learnt, sometimes through hard lessons, that to implement unit tests we need to design and build our code so that it is actually testable. In my mind, this is a benefit, since it forces us to think about the code we’re writing, and more often than not, a better design emerges from our efforts.

We all know that one of the biggest advantages of unit testing is that it affords us confidence when making future changes. We know we’re going to make them, so let’s help ourselves when we do. Unit testing is also an important ally when refactoring code (especially if you also practice continuous refactoring – like all good Developers should). A good example of what I mean by “design for test” came about with the release of ASP.NET MVC Preview 3.

Although based on a pattern which itself leads to increased testability (Model-View-Controller), prior to Preview 3 there were still some fiddly points that made testing controllers and their actions awkward. Actions were void which meant it was difficult to observe and test expectations about what the action did. With Preview 3 actions can now optionally return an ActionResult object, which is then executed later on in the rendering process by the MVC Framework. This refactoring increases the ability to unit test controllers and actions, and more importantly, it makes writing those tests easier since there is less of a requirement to mock. This is a good example of “design for test”.

It’s old news but most of us will know that C# 3.0 introduced a new keyword: var. This tiny keyword brings with it a great deal of power behind the scenes, most of which was intended for use with another C# 3.0 language feature, namely LINQ. Simply put, what var does is tell the compiler to infer the type being used rather than having it specified explicitly.

You can appreciate this benefit when working with LINQ, since the type being returned from a query may not be known in advance. Consider anonymous types for example, and their use with LINQ projection where you cannot explicitly determine the result type. With this scenario you have to utilize the var keyword:

string[] words = {"AA","BB", "Hello", "World", "CCC", "DDDD"};

var result = 
  from s in words 
  where s.Length >= 5
  select new { Word = s, Length = s.Length };

So, in the above example we’re returning instances of an anonymous type from a query that will contain two properties: Word, and Length. We have two options, either explicitly create a new type that defines those two properties, or use var. If we use a var declaration then we understand that those anonymously typed object instances can only be used locally. I have no problem at all with this use of var (since it is really what var was designed for). The same goes for anonymous types – they should only be used in the context of LINQ (unless they’re used for very localized purposes).

What about the following query instead?

string[] words = {"AA","BB", "Hello", "World", "CCC", "DDDD"};

var result = 
  from s in words 
  where s.Length >= 5
  select s;

To some this is acceptable, but to me it’s problematic. If we look at the line of code defining the query, we have no way of determining the type of the result variable other than to scan the lines of code above it (maybe you could call this human inference). Why would this be acceptable? Why would you want to have to scan code in order to determine a variable’s type?

Instead, I would use the following query and be explicit about the type (after all, it’s not anonymous):

IEnumerable<string> result = 
  from s in words 
  where s.Length >= 5
  select s;

Now it’s easy to see what the query is projecting (a collection of strings). It might be a few more characters to type, but it is much more readable by myself and my fellow Developers.

In short, I think that the over use of var can easily lead to unreadable code, and that as Developers, we owe it to ourselves to keep our code readable. One use of var outside the context of LINQ that I really like is shown below:

var hashtable = new Hashtable<int, List<MyClass>>();

You can still easily determine the type of the hashtable variable from the same line of code, and you’ve saved yourself from typing the type-name twice.

Another example of var laziness is shown below:

foreach (var word in words)
{
  word.??
}

Reliance on Intellisence is simply not an answer.

So you've installed Team Foundation Server and now you need to setup your permissions. There's quite a lot to follow in the TFS Installation Guide, so if you're using Active Directory, here's a digest of how I've recently defined permissions on a single-server deployment (this should work with both 2005 and 2008):

First, we have to remember that there are three areas where permissions have to be managed. TFS itself, SharePoint Services, and SQL Server Reporting Services. As far as I can tell, SQL Server Reporting Services appear to be the least secure of the three. When a user is assigned a Role Assignment it is not in relation to any particular Team Project.

There are also four distinct role types that we have to consider when thinking about permissions (summarized below):

• TFS administrators are those users who create Team Projects
• TFS project administrators are those users who manage Team Projects
• Everyone else is either a Contributor or a Reader

The approach that I have taken (obviously working in conjunction with an Active Directory Administrator), is to define two Active Directory domain groups called TFSAdministrators and TFSProjectAdministrators. TFSAdministrators is added to the SharePoint Administration Group (or the Farm Administration Group in SharePoint 2007). It is also added as a System Administrator for the site-wide security settings in SQL Server Reporting Services. Basically any user added to this group will then have the appropriate permissions to create Team Project Portals and Reports in both SharePoint and SQL Server Reporting Services.

The second group (TFSProjectAdministrators), gives Team Project Administrators the Content Manager Role Assignment within SQL Server Reporting Services. Finally, to support the Contributor and the Reader roles, we define a new Browser Role Assignment within SQL Sever Reporting Services for the Domain Users group (i.e., the group to which everyone on the Domain in a member).

The combination of these two Active Directory groups and their permissions within SharePoint and SQL Server Reporting Services, effectively means that there is no longer a need to manually add users to the appropriate Role Assignment in SQL Server Reporting Services. Instead, a user can be added to their appropriate Active Directory group. Since permissions in SQL Server Reporting Services are not relative to a Team Project, this makes things much more intuitive going forward. In fact, it is now possible to forget about SQL Server Reporting Services altogether, and instead focus on adding users to the Team Foundation Server groups (i.e., Team Foundation Administrators or [project_name]\Project Administrators), and then adding the user to an appropriate group in the Team Project Portal.

I think that this provides a sensible and intuitive approach in managing user permissions within TFS. One change that I might consider is not adding the Domain Users group to the Browser Role Assignment in SQL Server Reporting Services, since this effectively gives every user in the Domain the ability to view all reports.