• Unit of Work & Repository support for multiple frameworks
• Letting your Unit of Work & Repositories support multiple frameworks

A little while ago, I had to redesign the Unit of Work and Repository structure in a project at work. Naturally, I was quite happy to do so, as I have done a lot of research and development work on this topic already.

A requirement was that the unit of work should be able to work with multiple databases. I figured that the generic approach as described in my previous articles would work just as well to solve this issue. I was rather pleased when I discovered that the sample code, provided as download in one of my previous articles, worked with only a few modifications.

Another thing of beauty – which is slightly off-topic, but deserves to be mentioned – was to see the code working through a different inversion of control container. My code always used Castle Windsor for IoC and DI, but the project at work uses StructureMap. I had a little nerdgasm when I saw my code working in a completely different environment; it really gave me the feeling that I had written some very versatile code that can be implemented in different scenarios with very little effort!

On to the actual code now…

The project uses Entity Framework 4.1 and has no requirements to support different ORM tools. This allowed me to make a few minor code changes to facilitate EF 4.1 a little better.

Let’s start with the unit of work interface:

public interface IUnitOfWork : IDisposable
{
    void Commit();
}

/// <summary>
/// Generic unit of work interface for different DbContext objects.
/// </summary>
/// <remarks>
/// Keyword "out" is specified for the generic parameter
/// to allow casting (covariance).
/// </remarks>
/// <typeparam name="TContext">Concrete DbContext type.</typeparam>
public interface IUnitOfWork<out TContext> : IUnitOfWork
   where TContext : DbContext
{
    TContext Context { get; }
}

Very little changes in the code here. An out-keyword was added to the generic TContext parameter and an added restriction that TContext should always be of type DbContext (Entity Framework 4.1 specific change).

The only other change was done in the abstract Repository class:

public abstract class Repository<TEntity> : IRepository<TEntity>
    where TEntity : class
{
    private IUnitOfWork<DbContext> unitOfWork;
    private readonly IDbSet<TEntity> entitySet;

    /// <summary>
    /// Creates a new repository.
    /// </summary>
    /// <param name="unitOfWork">The unit of work to use.</param>
    public Repository(IUnitOfWork unitOfWork)
    {
        this.unitOfWork = (IUnitOfWork<DbContext>)unitOfWork;
        this.entitySet = this.unitOfWork.Context.Set<TEntity>();
    }
}

This code was modified to be able to cast the IUnitOfWork to an IUnitOfWork<DbContext>. This is another change specific for EF 4.1 to allow me to access the context and create an entity set.

And finally, the StructureMap registries tie everything together when bootstrapping the application:

    ForConcreteType<ConcreteContext>();

    ForConcreteType<AnotherConcreteContext>();

    ForConcreteType<UnitOfWork<ConcreteContext>>()
        .Configure
        .Ctor<ConcreteContext>();

    ForConcreteType<UnitOfWork<AnotherConcreteContext>>()
        .Configure
        .Ctor<AnotherConcreteContext>();

    For<ISomeRepository>()
        .Use<SomeRepository>()
        .Ctor<IUnitOfWork>()
        .Is<UnitOfWork<ConcreteContext>>();

    For<IOtherRepository>()
        .Use<OtherRepository>()
        .Ctor<IUnitOfWork>()
        .Is<UnitOfWork<AnotherConcreteContext>>();

I’m not an expert on StructureMap, so I’m not sure if this is the most efficient way to go, but here I define the concrete context objects for the databases as well as which context to use when initializing the repositories.

Hopefully this, combined with my previous posts, is enough to let you figure out the total picture on your own. If there actually is demand for another sample project, let me know in the comments and I’ll see if I can free up some time to make one.

Everywhere on the web you’ll be able to read about all the fantastic parts of Skyrim, so I’ll be focusing on not so nice parts of this game.

The interface is not intuitive at all. I’ve read that it’s slightly better on consoles, though not by much. It looks extremely elegant and clean, but it takes a lot of getting used to. The mouse cannot be used in most menus and everything will need to be done by keyboard. Which isn’t all that bad though… once I got the hang of the flow through the menus it works alright, but it’s a long and bumpy road to actually understand it.

In my first hours of playing Skyrim, I truly struggled with the interface:

• How exactly do I know which gear I’ve got equipped? I’m not able to see my character!
• Why on earth are my miscellaneous quests not tracked on the map? …the fuck?!
• What in the love of all that is holy do I need to do to be able to use my newly earned shout?! Stop telling me I need a dragon soul, I have one damn it!
• Generally it lacks explanation and the player is left on its own to figure out all the possibilities.

Another part I truly do not like are the controls of my horse. The amount of times that I accidentally fell off a cliff because the horse seemingly had a mind of its own is not funny. A hint for any future Skyrim players… never ever walk your horse to the edge of a cliff and assume you can walk backwards to back away from it. Maybe I’ve played Word of Warcraft for too long to expect my mount to just walk backwards.

The AI pathing seems to lack quite a bit of… intelligence as well. The amount of times that I’ve lost a companion in the woods somewhere can not be counted on both of my hands. Either they randomly run off the road to stand around in the woods for a while before deciding to get back to the road and follow me or simply wait somewhere until I return and fetch them.

They also do not like climbing rocks either… where I (and I suspect many other players) simply jump onto some rocks, the AI decides to run off searching for a proper path there. This caused such enormous frustration at one point when I was trekking through the wilderness…

All in all, while these things really are annoying… it’s not such a huge deal that the game itself isn’t enjoyable. At the moment I’m even favouring to play Skyrim over Assassin’s Creed: Revelations. For me, as a true AC fanboi, is quite stunning.

From today the front page of the website has a little rotating banner showing posts that I think are important for my audience. Or generally posts that required a lot of work and research and simply deserve to be in the spotlight!

My shortcomings as a designer (that’s probably the reason why I’m a software engineer…) have been glaringly obvious to me. I had the hardest time ever to make the website appear as I had in mind. I wanted to modernize the layout and have a nice, clean look with clear typography. I think I succeeded quite well there, but it was a bumpy road to find my way through the jungle of WordPress themes!

The other thing I’m getting increasingly frustrated with is finding the right plugin to create a fancy featured post slider on the frontpage. Again, there are so many plugins to choose from. Sadly though, many of them are either incompatible with the latest WordPress version or behave slightly different from what I’d like. Or… to make matters worse, behave exactly like it want, but aren’t customizable enough to make it look the way I originally intended.

The hunt continues… hopefully I’ll find an appropriate solution soon!

From this point of view I looked at Telerik again. What can they still offer me at this point, since I can’t afford to buy any licenses. In fact, I was pleasantly surprised! I knew they had some free tools, but I never quite realized which. I already knew of JustDecompile and the ASP.NET MVC components. To my delight, I discovered a free version of OpenAccess ORM! I will admit that this severely limits the toolbox that I got used to, but it’s still a pretty awesome toolbox to use.

A free version of OpenAccess is just a godsend! Due to previously bad experiences with Entity Framework, I didn’t want to go back to using that. Nor did I want to continue using NHibernate, even though it can do everything I can possibly think of… it’s always a pain in the backside to actually get it done. Sure, OpenAccess has it’s quirks and limitations, but at least there’s a company supporting their product actively and let’s not forget about the community contributions!

I don’t have much experience developing with the ASP.NET MVC framework, but knowing that Telerik’s controls are free to use might make me look into this option. I quite like the looks of MVC3 with the Razor view engine; it’s lifted a few of my main objections to working with the MVC framework. So, again… here I have an opportunity to continue to build applications with the help of an awesome control suite.

In fact, not having access to all the goodies that I’ve used for all these years might make me a better developer! I’m forced to reconsider my options and perhaps learn new techniques and start using those.

My thanks to the Telerik team: you’re not just pushing yourselves with every release, but pushing me as well to stay on top of my game! Continue the awesome work!

The garden has been a bit of a mess ever since I got to live in my new house. I knew I had to get my bum in gear at some point to tidy it up and make it look presentable. It all started with a bright idea to tidy up the pond first. It was just yucky, dirty, brown water and probably a nice little breeding place for all sorts of insects. Once done with the pond, I decided that the hedge on one side of the garden took up far too much space and should be taken out completely. What followed was a tiny nightmare, really.

The previous owners had simply let the hedge grow wildly along almost the entire length of the garden. When removing the hedge, an old, cracked and sagged concrete fence was revealed. In fact, the hedge was supporting the fence, so we couldn’t remove the hedge without breaking down the fence as well. Further down the garden an old, wooden fence was revealed that fell apart at the merest touch! After having a chat with the neighbours we concluded that the concrete fence must have been at least fifty(!) years old. Now I found myself in a situation where my garden was an absolute disgrace. I was looking at broken fences, riddled with remains of the hedge that was still holding it together. The fences had to be removed and replaced with an entirely new fence. Ouch! Quite an unexpected expense there. After contacting a company to take care of my horrible fences, work continued on the garden. All plants, small trees and grass was removed. Now my garden look at it worst. Now I had not only broken fences, but a bare patch of soil and mud as well.

Luckily, a new fence could be placed in just a few weeks time and that opened up the road to start building up the garden again. It was still a lot of work though. I had far too much soil in my garden and it was spread in bumps and lumps all over my garden. I had at least five wheelbarrows of soil that I had to get rid of! Thankfully, my neighbours told me they needed soil for their garden and I was able to provide them with seven wheelbarrows full of it! Now I could make a path in my garden, fill it up with gravel and place artificial grass on both sides of it.

It was such a relief to have a decent looking garden again. It’s not done yet, unfortunately. I still need a patch of artificial grass and some additional gravel. Oh, and guess what… the pond still needs doing as well. The bloody pond that started it all is still not done!

This is turning into a multi-weekend project. Thankfully my family has been a great help with all the hard work and hopefully in the upcoming weeks it will all pay off when it’s completely done!

Anyway, to get back on topic. There’s a new Assassin’s Creed coming this year, November to be precise! It’s going to be concluding the story of Ezio’s life. Many people had hoped for a new main character, but I’m very happy to have Ezio back for more action! As far as I understand, the game will give us answers instead of just raising more questions. It’s supposed to make us understand the link between Altaïr, Ezio and Desmond and finish that part of the story. Nothing has been mentioned about finishing Desmond’s story, so expect more Assassin’s Creed game in the future!

Here are a few trailers from the E3 2011, to wet everyone appetites (and give me a nerdgasm):

It’s so weird to realize that I still have clear and vivid memories of some of the clan matches or midnight gaming sessions; loading up a single M4 with two ammo clips and two grenades, only to make a mad rush at the enemy base and surprise blast my way through the enemy team was so awesome! Sometimes I’d die in one or two minutes, but I would have four or five kills behind my name! Sweet!

I loved this game so much that I remember playing until deep into the night in the weekends. I would come home late in the evening from my work as dish washer in a restaurant, fire up my computer to play some rounds of SF with my buddies and have an awesome time until 4AM in the morning…

It must be around 10 years ago, if not more, that I played this game. I remember taking my first driving lessons when I was working in that restaurant. That was back in the year 2000. So, that means it was in fact 11 years ago. It’s probably more, because I played this game for quite a while already before I learned how to drive. Goddamn! I’m getting old!

Ahh, the good old days of playing in a relatively small community where pretty much everyone knew each other. I truly miss that. Browsing through the server list, finding buddies or simply hopping on my favourite server, knowing I would find friends there. These days I play games (World of Warcraft and StarCraft) where the communities are so massive that everything is fairly anonymous. Being a jerk to someone doesn’t really matter… it’s highly unlikely you’ll play together again anyway (unless it’s a guild mate of course).

Maybe remembering what it was like to belong in a tightly-knit community sparked this longing in me. I’m going to have to find out if the original Unreal Tournament can still be installed and played on a current day Windows 7 64-bits system! I was thinking it might be fun to put up an old-school SF server. So, if any old veterans (SF 1.55 – SF 1.85) out there accidentally read this post and is interested in having a brawl, be sure to drop me a message!

Unfortunately, I  couldn’t find any proper screenshots to post along with this message, but I found some nice youtube videos! Enjoy!

The most important jobs in my new house have been done. Pretty much all the furniture have been put together; the only missing piece is a couch for in the living room, but other than that I think we’re pretty much settled in. There are still loads of “little” jobs to do though: organizing all the paperwork that has been piling up, reorganizing the cupboards and closets before they drive me mad, generally tidying up all over the place…

Best news of all though… I am no longer disconnected from the rest of the world! The fibre optic connection has been made and my Internet, TV and telephone lines are all active! I never realised how much easier life can be with an active Internet connection! Things such as online banking and shopping are a few of those comforts that I have missed the most!

It’s been a bit quiet with new entries here lately and that’s mainly because I’ve been extremely busy. My time in the last few weeks has been spent on preparing to move into my new house! In the past five days I’ve done nothing but heavy lifting, cleaning, painting, putting furniture together (IKEA ftw!) and all the other lovely little chores that come with moving. Aside from all the IKEA boxes in my living room, it’s starting to look like a proper little home already! Hurray!

The bad news is that I will be without an internet connection for a while, so no more regular updates until that’s sorted. The good news however, is that I’ll be getting a super speedy fibre optic connection! Hopefully that will be worth the wait!

I’ll only have a web connection available at work, so I will only be able to write a few short posts for now!