IRepository
Posted on August 4, 2008
As I'm testing features of ASP.NET MVC, I'm noticing that it would be really nice to be able perform non-persistent CRUD operations on POCO's. Meaning, i need data, i need objects, but I don't want to set up a test database for these tests. I need to be able to create a class, and then create lists of instances of that class, and then add new ones, edit existing ones, delete some, exactly the same stuff I'd normally do, just no database.
I searched on "IRepository
Here is my initial version of IRepository
public interface IRepository<TModel>
where TModel : IModel, new()
TModel Find(int id);
IEnumerable<TModel> FindAll();
void Save(TModel model);
void Delete(TModel model);
int Count { get; }
}
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It's pretty simple, and does only the bare minimum. Every class that wants to participate in a repository must implement IModel, this tells the repository that anything in it is guaranteed to have an int ID property, by which it can query:
public interface IModel{
int ID { get; set; }
}
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Let's say you create a class, Customer. In order to enable it to be usable in a repository, it needs to implement IModel, so the class might look something like this:
public class Customer : IModel {
public int ID { get; set; } //required by IModel
public string FirstName{ get; set; }
public string LastName{ get; set; }
}
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Using the repository is simple,
//first create a customer repository
IRepository<Customer> repo = new Repository<Customer>();
//now add some customers
repo.Save(new Customer() { FirstName = "Chris", LastName = "Carter" });
repo.Save(new Customer() { FirstName = "Emmitt", LastName = "Carter" });
//make sure they are in there
Assert.AreEqual(2, repo.Count);
Assert.AreEqual("Emmitt", repo.Find(2).FirstName);
//let's remove one
repo.Delete(repo.Find(2));
//make sure it's gone
Assert.AreEqual(1, repo.Count);
Assert.IsNull(repo.Find(2));
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I bundled up the code in a project inspired by Rhino Commons called EPS.Common, the source is here: http://svn.chrisjcarter.com/public/EPS. I have a sample ASP.NET MVC(Preview 4) solution available for download here(less than 100k).
