Using Telerik OpenAccess ORM with ServiceStack
It is very easy to integrate OpenAccess ORM as a persistence solution and use it from a ServiceStack web service. Let’s start with the setup of ServiceStack. You could use the NuGet package manager to do that:
Install-Package ServiceStack
Before moving to the implementation of the service we will register it together with its dependencies. The following code snippet should be added under the Global.asax.cs file:
public class MayLilyAppHost : AppHostBase{ public MayLilyAppHost() : base("OpenAccess ORM and ServiceStack integration sample", typeof(MayLilyAppHost).Assembly) { } public override void Configure(Container container) { container.RegisterAutoWiredAs<Configuration, IConfiguration>().ReusedWithin(ReuseScope.Container); container.RegisterAutoWiredAs<MayLilyMetadataSource, IMetadataSource>().ReusedWithin(ReuseScope.Container); container.RegisterAutoWiredAs<MayLilyContext, IDbMigrator>().ReusedWithin(ReuseScope.None); container.RegisterAutoWiredAs<MayLilyContext, IMayLilyContext>().ReusedWithin(ReuseScope.None); }}public static class AppBootstrapper{ public static void Start() { MayLilyAppHost appHost = new MayLilyAppHost(); appHost.Init(); IDbMigrator migrator = appHost.Container.Resolve<IDbMigrator>(); migrator.MigrateSchema(); migrator.SeedData(); }}public class Global : HttpApplication{ protected void Application_Start(object sender, EventArgs e) { AppBootstrapper.Start(); }}
There are three parts in a ServiceStack service: Request DTO, Response DTO and the service implementation. In this blog post we will read category data filtered based on its identity. This means we need an appropriate request DTO:
[Route("/get-category/{CategoryID}", Verbs = "GET")]public class GetCategory{ public int CategoryID { get; set; }}
The service will return the following response DTO:
public class GetCategoryResponse{ public CategoryDto Result { get; set; } public ResponseStatus ResponseStatus { get; set; }}public class CategoryDto{ public int Id { get; set; } public string Name { get; set; } public string Description { get; set; }}
Note the name of the response DTO. It is constructed by appending Response to the request DTO name. This is the convention used by ServiceStack. To support automatic exception handling a ResponseStatus property is added to the response DTO class.
And here the implementation of the service itself:
public class CategoryService : Service{ private readonly IMayLilyContext context; public CategoryService(IMayLilyContext context) { this.context = context; } public object Get(GetCategory request) { Category result = this.context.Categories.Find(request.CategoryID); if (result == null) { throw HttpError.NotFound(string.Format("Unable to find category with id {0}.", request.CategoryID)); } return new GetCategoryResponse { Result = new CategoryDto { Id = result.Id, Name = result.Name, Description = result.Description } }; } public override void Dispose() { this.context.Dispose(); }}
If everything is configured correctly, you could run the service and go to http://[server_uri]/get-category/1 to see your OpenAccess ORM ServiceStack web service in action.
The complete demo application can be found here.