Back-end

To get the back end in place, I introduced two new technologies.

Firstly, I introduced Unity as my dependency injection (IoC) container. This means that I can couple the controller, service and data access layers of the application at run time through dependency injection. As the controller instance is created by the MVC 3 framework, I needed a way of telling MVC to use my unity container. After some internet digging I found that the MVC framework provides an interface that can be used as an adapter for the Unity container. All I had to to was wrap the Unity container exposing the IDependencyResolver interface and then set the resolver in MVC using DependencyResolver.SetResolver. Quite a neat solution I thought.

Secondly, I introduced an entity framework code-first context. I had already used code-first on another project and was very impressed. Using the plain old CLR object (POCO) classes that I had created when designing the front end, I could generate a database, seed it with data and read back data using a LINQ to SQL statement. This all seems like quite a lot of work, but it was remarkably straightforward. The only thing that I needed to do to the POCO class was add a property to represent the primary key (public int id { get; set; }).

The data seeding is done by creating a class that inherits from DropCreateDatabaseIfModelChanges. So each time the application starts, this will check for changes and rebuild and reseed the database if required.

Well, we are almost done for the core of this application. The next piece of work will be adding detail links to keywords in the maintenance task content. I'm going to need to have a little think about how I'm going to achieve this. All I know is that it will involve dynamically adding in links to the content at some point.