I'm trying to work with NInject in my MVC 3 application, and i have one question.
Interface
public interface ITalesRepository
{
IEnumerable<Tale> GetAllTales();
}
Repository
public class TalesRepository : ITalesRepository
{
private FairyTalesMVC3DataContext _dataContext;
public TalesRepository(FairyTalesMVC3DataContext dataContext)
{
_dataContext = dataContext;
}
public IEnumerable<Tale> GetAllTales()
{
return _dataContext.Tales.OrderBy(c => c.NameAn);
}
}
Home controller
public class HomeController : Controller
{
private readonly ITalesRepository _talesRepository;
public HomeController(ITalesRepository talesRepository)
{
_talesRepository = talesRepository;
}
public ActionResult Index()
{
ViewBag.Tales = _talesRepository.GetAllTales();
return View();
}
}
So, i need to initialize my TalesRepository with DataContext, and now it is so:
private void RegisterDependencyResolver()
{
var kernel = new StandardKernel();
kernel.Bind<ITalesRepository>().To<TalesRepository>().WithConstructorArgument("dataContext", new FairyTalesMVC3DataContext(ConfigurationManager.ConnectionStrings["dbFairyTalesConnectionString"].ConnectionString));
DependencyResolver.SetResolver(new NinjectDependencyResolver(kernel));
}
So, my question, is it ok or something wrong?
First of all:
public IEnumerable<Tale> GetAllTales()
{
return _dataContext.Tales.OrderBy(c => c.NameAn);
}
I would add .ToList() to the end. Else you'll get data layer exceptions in your presentation layer which is not fine.
Next, I would recommend that you switch to ViewModels instead of using ViewBag. It's a lot easier to prevent that logic leaks into the views if you are using ViewModels. Since you can add the logic to the ViewModel and thus get the same behaviour in all views using the model.
Your application should inherit from NinjectHttpApplication. It registers dependency resolver, so you don't have to do it.
You should also override CreateKernel in application class and register your own module with bindings:
public class MvcApplication : NinjectHttpApplication
{
protected override IKernel CreateKernel()
{
return new StandardKernel(new INinjectModule[] {new MvcModule()});
}
}
public class MvcModule : NinjectModule
{
public override void Load()
{
Bind<ITalesRepository>().To<TalesRepository>();
Bind<FairyTalesMVC3DataContext>().To<FairyTalesMVC3DataContext>().InRequestScope();
}
}
Related
The old controller code with Concrete dependencies:
public SomeController: Controller
{
public SomeController()
{
}
public ActionResult Default()
{
**Something something = new Something(Request.ServerVariables["HTTP_X_REWRITE_URL"].ToString());**
something.SomeMethod();
}
}
The new Controller code with TDD focus:
public SomeControllerNew: Controller
{
private readonly ISomething _something;
public SomeControllerNew(ISomething something)
{
_something = something;
}
public ActionResult Default()
{
_something.SomeMethod();
}
}
PROBLEM:
Now in new TDD approach i need to invoke constructor where I am registering the Interface. I have put it in UnityBootstraper common file, Something like:
var container = new UnityContainer();
container.RegisterType();
**Something something = new Something(Request.ServerVariables["HTTP_X_REWRITE_URL"].ToString());**
something.SomeMethod();
This is not working here. Error is quite clear:
Object reference required for non-static field, method, property 'System.Web.Mvc.Controller.Request.get'.
I can't figure out how i can access http request here in UnityBootstrapper?
Edit:
Trying to do all this in RegisterRoutes.
public class RouteConfig
{
public static void RegisterRoutes(RouteCollection routes)
{
DependencyResolver.SetResolver(new Unity.Mvc3.UnityDependencyResolver(UnityBootstrapper.Initialise()));
var container = new UnityContainer();
container.RegisterType<ISometing, Something>();
}
}
One way to do it is to create an abstract factory like this:
public interface ISomethingFactory
{
ISomething Create(string url);
}
public class SomethingFactory : ISomethingFactory
{
public ISomething Create(string url)
{
return new Something(url);
}
}
And make your controller depend on it like this:
public class SomeControllerNew: Controller
{
private readonly ISomething _something;
public SomeControllerNew(ISomethingFactory somethingFactory)
{
_something = somethingFactory.Create(Request.ServerVariables["HTTP_X_REWRITE_URL"].ToString();
}
public ActionResult Default()
{
_something.SomeMethod();
}
}
A better approach (IMO) is to use a custom Controller Factory instead of using the Dependency Resolver like this:
public class CustomFactory : DefaultControllerFactory
{
public override IController CreateController(RequestContext requestContext, string controllerName)
{
var request = requestContext.HttpContext.Request; //Here we have access to the request
if (controllerName == "Some") //Name of controller
{
//Use the container to resolve and return the controller.
//When you resolve, you can use ParameterOverride to specify the value of the string dependency that you need to inject into Something
}
return base.CreateController(requestContext, controllerName);
}
}
This way you don't have to introduce the ISomethingFactory, and your controller would still depend on ISomething directly.
You would need to tell the MVC framework about this custom controller factory like this (in Application_Start):
ControllerBuilder.Current.SetControllerFactory(new CustomFactory());
I am having hard time using Repository patterns, is it possible to create two repository patterns?? One for products, another for orders??
I failed to connect these repositories to databases. I know how to work with one repository, but two with IRepository where T: Entity I am getting lost. The question is whether I can create and will not volatile the rules if create ProductRepository and OrderRepository?
Repository pattern is widely used in DDD (Domain-Driven-Design) you could check it here: http://www.infoq.com/minibooks/domain-driven-design-quickly. Also check this book: http://www.amazon.com/Domain-Driven-Design-Tackling-Complexity-Software/dp/0321125215
With regards to your question:
Yes you can use more than 1 repository. Look in this example I use nHibernate session:
// crud operations
public abstract class Repository<T> : IRepository<T> where T : class
{
protected readonly ISession _session;
public Repository(ISession session)
{
_session = session;
}
public T Add(T entity)
{
_session.BeginTransaction();
//_session.SaveOrUpdate(entity);
_session.Save(entity);
_session.Transaction.Commit();
return entity;
}
//...
}
public interface IRepository<T>
{
T Add(T entity);
T Update(T entity);
T SaveOrUpdate(T entity);
bool Delete(T entity);
}
Then my repository looks like this:
public class ProjectRepository : Repository<Project>, IProjectRepository
{
// Project specific operations
}
public interface IProjectRepository : IRepository<Project>
{
Project Add(Project entity);
Project Update(Project entity);
Project find_by_id(int id);
Project find_by_id_and_user(int id, int user_id);
//..
}
Then using Ninject:
Global.asax.cs
protected void Application_Start()
{
AreaRegistration.RegisterAllAreas();
RegisterGlobalFilters(GlobalFilters.Filters);
RegisterRoutes(RouteTable.Routes);
ControllerBuilder.Current.SetControllerFactory(new NinjectControllerFactory());
}
Then in NinjectControllerFactory I load the modules:
public class NinjectControllerFactory : DefaultControllerFactory
{
private IKernel kernel = new StandardKernel(new NhibernateModule(), new RepositoryModule(), new DomainServiceModule());
protected override IController GetControllerInstance(RequestContext context, Type controllerType)
{
//var bindings = kernel.GetBindings(typeof(IUserService));
if (controllerType == null)
return null;
return (IController)kernel.Get(controllerType);
}
}
NhibernateModule:
public class NhibernateModule : NinjectModule
{
public override void Load()
{
string connectionString =
ConfigurationManager.ConnectionStrings["sqlite_con"].ConnectionString;
var helper = new NHibernateHelper(connectionString);
Bind<ISessionFactory>().ToConstant(helper.SessionFactory).InSingletonScope();
Bind<ISession>().ToMethod(context => context.Kernel.Get<ISessionFactory>().OpenSession()).InRequestScope();
}
}
Then in RepositoryModule I use Ninject Conventions to automatically bind all repositories with their interfaces:
using Ninject.Extensions.Conventions;
public class RepositoryModule : NinjectModule
{
public override void Load()
{
IKernel ninjectKernel = this.Kernel;
ninjectKernel.Scan(kernel =>
{
kernel.FromAssemblyContaining<ProjectRepository>();
kernel.BindWithDefaultConventions();
kernel.AutoLoadModules();
kernel.InRequestScope();
});
}
}
And in the end I basically inject Repository in the controller:
public class projectscontroller : basecontroller
{
private readonly IProjectRepository _projectRepository;
public projectscontroller(IProjectRepository projectRepository)
{
_projectRepository = projectRepository;
}
[AcceptVerbs(HttpVerbs.Get)]
[Authorize]
public ActionResult my()
{
int user_id = (User as CustomPrincipal).user_id;
var projectList = _projectRepository.find_by_user_order_by_date(user_id);
var projetsModel = new ProjectListViewModel(projectList);
return View("my", projetsModel);
}
}
This way you just create new Repository and its Interface and it will be automatically injected to your controller.
I am using asp.net mvc 3, ninject 2.0 and the ninject mvc 3 plugin.
I am wondering how do I get service layers into my filter(in this case an authorization filter?).
I like to do constructor inject so is this possible or do I have to property inject?
Thanks
Edit
I have this for property inject but my property is always null
[Inject]
public IAccountService AccountServiceHelper { get; set; }
protected override bool AuthorizeCore(HttpContextBase httpContext)
{
// check if context is set
if (httpContext == null)
{
throw new ArgumentNullException("httpContext");
}
// check if user is authenticated
if (httpContext.User.Identity.IsAuthenticated == true)
{
// stuff here
return true;
}
return false;
}
/// <summary>
/// Application_Start
/// </summary>
protected void Application_Start()
{
// Hook our DI stuff when application starts
IKernel kernel = SetupDependencyInjection();
RegisterMaps.Register();
AreaRegistration.RegisterAllAreas();
RegisterGlobalFilters(GlobalFilters.Filters);
RegisterRoutes(RouteTable.Routes);
}
public IKernel SetupDependencyInjection()
{
IKernel kernel = CreateKernel();
// Tell ASP.NET MVC 3 to use our Ninject DI Container
DependencyResolver.SetResolver(new NinjectDependencyResolver(kernel));
return kernel;
}
protected IKernel CreateKernel()
{
var modules = new INinjectModule[]
{
new NhibernateModule(),
new ServiceModule(),
new RepoModule()
};
return new StandardKernel(modules);
}
public class ServiceModule : NinjectModule
{
public override void Load()
{
Bind<IAccountService>().To<AccountService>();
}
}
Edit
I upgraded to ninject 2.2 and get finally got it work.
Edit 2
I am going to try and do the constructor way for my authorize filter but I am unsure how to pass in the Roles. I am guessing I have to do it through ninject?
Edit 3
This is what I have so far
public class MyAuthorizeAttribute : AuthorizeAttribute
{
private readonly IAccountService accountService;
public MyAuthorizeAttribute(IAccountService accountService)
{
this.accountService = accountService;
}
protected override bool AuthorizeCore(HttpContextBase httpContext)
{
return base.AuthorizeCore(httpContext);
}
}
this.BindFilter<MyAuthorizeAttribute>(FilterScope.Controller, 0)
.WhenControllerHas<MyAuthorizeAttribute>();
[MyAuthorize]
public class MyController : BaseController
{
}
It tells me it want's a no parameter constructor. So I must be missing something.
The problem with filters is that they are attributes. And if you define a constructor of an attribute that expects some dependency you will never gonna be able to apply it to any method: because all values that you pass to attributes must be known at compile time.
So basically you have two possibilities:
Use Ninject to apply the filter globally instead of decorating your controllers/actions with it:
public interface IFoo { }
public class Foo : IFoo { }
public class MyFooFilter : AuthorizeAttribute
{
public MyFooFilter(IFoo foo)
{
}
}
and then configure the kernel:
kernel.Bind<IFoo>().To<Foo>();
kernel.BindFilter<MyFooFilter>(FilterScope.Action, 0).When(
(controllerContext, actionDescriptor) =>
string.Equals(
controllerContext.RouteData.GetRequiredString("controller"),
"home",
StringComparison.OrdinalIgnoreCase
)
);
Use property injection:
public interface IFoo { }
public class Foo : IFoo { }
public class MyFooFilter : AuthorizeAttribute
{
[Inject]
public IFoo Foo { get; set; }
}
and then configure the kernel:
kernel.Bind<IFoo>().To<Foo>();
and decorate some controller/action with your custom filter:
[MyFooFilter]
public ActionResult Index()
{
return View();
}
See this question /answer here:
Setup filter attribute for dependency injection to accept params in constructor
and here
Dependency Injection with Ninject and Filter attribute for asp.net mvc
Historically my controllers have repositories declared on each controller which are injected through StructureMap and this is working fine for me.
But my new project will likely be using the same repositories for each controller.
Due to this i created a BaseController and inherit all controllers from here.
My repositories now live in Base but the injection is not working.
Can it work like this or does constructor injection have to take place on each controller?
public static void BootStructureMap()
{
ObjectFactory.Initialize(x =>
{
x.Scan(scanner =>
{
scanner.TheCallingAssembly();
scanner.WithDefaultConventions();
scanner.AddAllTypesOf<IController>().NameBy(type => type.Name.Replace("Controller", "").ToLower());
});
x.For(typeof(IGenericRepository<>)).Use(typeof(GenericRepository<>));
});
}
Working:
public class TransactionController : Controller
{
public IGenericRepository<ITransaction> TransactionRepository { get; set; }
public TransactionController(IGenericRepository<ITransaction> transactionRepository)
{
this.TransactionRepository = transactionRepository;
}
public ActionResult Index()
{
var transactions = this.TransactionRepository.Query.AsEnumerable();
return View(transactions);
}
Not working:
public class BaseController : Controller
{
public IGenericRepository<ITransaction> TransactionRepository { get; set; }
public BaseController(IGenericRepository<ITransaction> transactionRepository)
{
this.TransactionRepository = transactionRepository;
}
protected BaseController()
{
}
}
public class TransactionController : BaseController
{
public ActionResult Index()
{
var transactions = base.TransactionRepository.Query.AsEnumerable();
return View(transactions);
}
}
You have to inject your repository into BaseController somehow. If your last piece of code is the real code you have then it seems that BaseController is initialized through protected parameterless constructor.
Add the constructor to TransactionController:
public TransactionController(IGenericRepository<ITransaction> transactionRepository) : base(transactionRepository)
{
}
Can use Poor Man's Dependency Injection - used in NerdDinner application
public BaseController() : this(new Message())
{
}
Or
Refer Phill's link
tdd-and-dependency-injection-with-asp.net-mvc.aspx
Override DefaultControllerFactory
public class SMControllarFactory : DefaultControllerFactory
In
application start
protected void Application_Start()
{
ControllerBuilder.Current.SetControllerFactory(new SMControllarFactory());
I am very new to Ninject and am trying Ninject 2 with MVC and Linq. I have a SqlProductRepository class and all I want to know is what's the best way of passing the connectionstring in the constructor if I am injecting the Repository object in the controller.
public class SqlProductRepository:IProductRepository
{
private Table<Product> productsTable;
public SqlProductRepository(string connectionString)
{
productsTable = (new DataContext(connectionString)).GetTable<Product>();
}
public IQueryable<Product> Products
{
get { return productsTable; }
}
}
This is my ProductController class where I am injecting the Repository:
public class ProductsController : Controller
{
private int pageSize = 4;
public int PageSize { get { return pageSize; } set { pageSize = value; } }
IProductRepository _productsRepository;
[Inject]
public ProductsController(IProductRepository productRepository)
{
_productsRepository = productRepository;
}
public ViewResult List(int page)
{
return View(_productsRepository.Products
.Skip((page - 1) * pageSize)
.Take(pageSize)
.ToList()
);
}
}
Can somebody please guide me regarding this?
You can set it up in your binding
_kernel.Bind<IProductRepository>()
.To<SqlProductRepository>()
.WithConstructorArgument("connectionString",yourConnectionString );
You're doing:
new DataContext(connectionString)
in your code - this is the very newing and binding to classes you're trying to push out of your code by using a DI container. At the very least, consider adding an IConnectionStringSelector interface or something like that. You dont want to have 20 Bind calls for 20 repositories - you want a higher level abstraction than that.
I'd suggest the best solution is that you should be demanding either an IDataContext or an IDataContextFactory in the constructor instead and letting that worry about it.
You could supply the connection string as a constructor argument when binding the SqlProductRepository to the IProductRepository interface.
public class LinqToSqlModule : NinjectModule
{
public override void Load()
{
Bind<IProductRepository>().To<SqlProductRepository>()
.WithConstructorArgument(connectionString, "connectionstring");
}
}
I would suggest a slightly different approach. First of all, you might want to create a binding for the DataContext class in the kernel. You could do so by using a provider class to create your DataContext passing the connection string as an argument to its constructor. Then you bind the DataContext to the DataContextProvider.
public class DataContextProvider : Provider<DataContext>
{
protected override DataContext CreateInstance(IContext context)
{
string connectionString = "connectionstring";
return new DataContext(connectionString);
}
}
public class LinqToSqlModule : NinjectModule
{
public override void Load()
{
Bind<DataContext>().ToProvider<DataContextProvider>();
Bind<IProductRepository>().To<SqlProductRepository>();
}
}
Next modify the constructor of SqlProductRepository class to accept a DataContext object instead.
public class SqlProductRepository : IProductRepository
{
private readonly DataContext context;
public ProductRepository(DataContext context)
{
this.context = context;
}
public IQueryable<Product> Products
{
get { return context.GetTable<Product>(); }
}
}
By the way you don't have to decorate your constructor with the Inject attribute. Ninject will select the constructor with the most parameters by default.
Please refer below code snap:
//Bind the default connection string
public void BindDataContext()
{
ConstructorArgument parameter = new ConstructorArgument("connectionString", "[Config Value]");
Bind<DataContext>().ToSelf().InRequestScope().WithParameter(parameter);
}
//Re-Bind the connection string (in case of multi-tenant architecture)
public void ReBindDataContext(string cn)
{
ConstructorArgument parameter = new ConstructorArgument("connectionString", cn);
Rebind<DataContext>().ToSelf().InRequestScope().WithParameter(parameter);
}
For more information, please visit below link
MVC3, Ninject and Ninject.MVC3 problem