I am trying to use Ninject and OpenAccess for the first time. Please help me with the following. Here is what my project looks like...
public class ContentController : Controller { private ContentService contentSvc; public ContentController(ContentService contentSvc) { this.contentSvc = contentSvc; } }
The following class is under a folder in my web app.
public class ContentService { private IContentRepository contentRepository; public ContentService(IContentRepository contentRepository) { this.contentRepository = contentRepository; } public void InsertContent(Content content) { contentRepository.InsertContent(content); } }
The following repository belongs to a separate assembly.
public class ContentRepository : IContentRepository { DBContext db; public ContentRepository(DBContext _db) { db = _db; } public void InsertContent(Content content) { db.Add(content); } }
Here is what Ninject binding look like..
kernel.Bind<ContentService>().To<ContentService>().InRequestScope(); kernel.Bind<IContentRepository>().To<ContentRepository>().InRequestScope().WithConstructorArgument("_db", new DBContext());
Everything works fine if I fetch one page at a time. I am using a simple tool 'XENU' to fetch multiple pages simultaneously. This is when I get errors with DBContext by fetching multiple pages at a time.
I am not sure if Ninject is dosposing the DBContext in each REQUEST?? I get different errors, e.g. 'Object reference not set to an instance of an object.', OR 'ExecuteReader requires an open and available Connection. The connection's current state is open.'
I have ContentService under a folder in my MVC web app. ContentRepository is a separate assembly. I will be adding business logic in ContentService and use 'ContentRepository' only for CRUD operations. Also, please let me know if this architecture is okay or is there a better way to create services and repositories.
First, DbContext is a lightweight object; it is designed to be used once per business transaction. Making your DbContext a Singleton and reusing it throughout the application can cause other problems, like concurrency and memory leak issues.
A DbContext instance represents a combination of the Unit Of Work and Repository patterns such that it can be used to query from a database and group together changes that will then be written back to the store as a unit. DbContext is conceptually similar to ObjectContext.
Here's how I would do your Ninject bindings,
kernel.Bind<DBContext>().ToSelf().InRequestScope(); kernel.Bind<ContentService>().ToSelf().InRequestScope(); kernel.Bind<IContentRepository>().To<ContentRepository>().InRequestScope();
This pattern should work fine in the example above with EF and Ninject.
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