I am reading this article:
https://docs.asp.net/en/latest/tutorials/first-web-api.html.
and they say. you have to put this:
using System.Collections.Generic;
using Microsoft.AspNetCore.Mvc;
using TodoApi.Models;
namespace TodoApi.Controllers
{
[Route("api/[controller]")]
public class TodoController : Controller
{
public TodoController(ITodoRepository todoItems)
{
TodoItems = todoItems;
}
}
}
But where is TodoItems declared?
Do I something wrong? Or is it mistake in the article?
Because If I put this in the file:
public ITodoRepository TodoItems { get; private set; }
The error goes away. But is this correct?
It's probably mistake. You should declare it as:
public class TodoController : Controller
{
private readonly ITodoRepository TodoItems;
public TodoController(ITodoRepository todoItems)
{
TodoItems = todoItems;
}
}
Here is using dependency injection by constructor.
So, I think that declaring of TodoItems as a public property is not a good idea. It should be a private readonly field that initializing only in constructor. In other case if you going to use inheritance it might be declared as a protected.
Related
I have tried to make an MVC news system. I started by the use a pluralsight tutorial which was used to create a department with employees. I changed the idea to fit my own purposes, changing the departments to "category" and employees to "newspost". This all works out fine, but now I want to remove the categories, since I don't need categories for my news system. But I can't add to the database using entityframework when I do this.
I have an interface for the datasource that looks like this:
INewMvcSiteDataSource
public interface INewMvcSiteDataSource
{
IQueryable<NewsPost> NewsPosts { get; }
void Save();
}
This is inherited by my DB Context class:
NewMvcSiteDb
public class NewsMvcSiteDb : DbContext, INewMvcSiteDataSource
{
public NewsMvcSiteDb() : base("DefaultConnection")
{
}
public DbSet<NewsPost> NewsPosts { get; set; }
IQueryable<NewsPost> INewMvcSiteDataSource.NewsPosts
{
get { return NewsPosts; }
}
public void Save()
{
SaveChanges();
}
}
I then want to use it in the controller to add a newspost to the database:
NewsController
var newsPost = new NewsPost()
{
Subject = newsModel.Subject,
Content = newsModel.Content,
ImagePath = newsModel.ImagePath
};
_db.NewsPosts.Add(newsPost);
_db.Save();
But this is where the ADD fails with the message: 'System.Linq.IQueryable' does not contain a definition for 'Add' and no extension method 'Add' accepting a first argument of type 'System.Linq.IQueryable' could be found (are you missing a using directive or an assembly reference?)
Now as the error says, its caused by using IQueryable, but I have no idea how else to do it.
Can you guys help?
Thanks.
If you don't mind exposing DbSet via your interface (some people don't like the ORM bleeding into the application),you should be able to do the following:
public interface INewMvcSiteDataSource
{
DbSet<NewsPost> NewsPosts { get; }
void Save();
}
public class NewsMvcSiteDb : DbContext, INewMvcSiteDataSource
{
public NewsMvcSiteDb() : base("DefaultConnection")
{
}
public DbSet<NewsPost> NewsPosts { get; set; }
public void Save()
{
SaveChanges();
}
}
I am learning ServiceStack and developing simple demo for helloworld, but could not find namespace for ISservice interface, my code as per below:
public class Hello
{
public string name { get; set; }
}
public class HelloResponse
{
public string Result { get; set; }
}
public class HelloService : **IService**<Hello>
{
public object Execute(Hello request)
{
return new HelloResponse { Result = "Hello" + request.name };
}
}
public class HelloAppHost : AppHostBase
{
public HelloAppHost() : base("Hello Web Services", typeof(HelloService).Assembly) { }
public override void Configure(Funq.Container container)
{
Routes.Add<Hello>("/hello")
.Add<Hello>("/hello/{Name}");
}
}
Can anyone please tell me what namespace or DLL I need to add for IService interface?
ServiceStack's IService<T> is in the ServiceStack.ServiceHost namespace which lives in the ServiceStack.Interfaces.dll, why here's the class:
https://github.com/ServiceStack/ServiceStack/blob/master/src/ServiceStack.Interfaces/ServiceHost/IService.cs
Note: If you're just starting out, it's probably better to inherit from ServiceStack.ServiceInterface.ServiceBase<T> and override the Run() method which is a useful base class that provides things like auto exception handling for you.
If you want to be able run different code for different HTTP Verbs e.g GET/POST/PUT/DELETE (i.e. creating REST web services) than you want to inherit from RestServiceBase instead and override its OnGet/OnPost/OnPut/OnDelete methods.
I am trying to learn TDD/BDD using NUnit and Moq.
The design that I have been following passes a DataService class to my controller to provide access to repositories.
I would like to Mock the DataService class to allow testing of the controllers.
There are lots of examples of mocking a repository passed to the controller but I can't work out how to mock a DataService class in this
scenerio.
Could someone please explain how to implement this?
Here's a sample of the relevant code:
[Test]
public void Can_View_A_Single_Page_Of_Lists()
{
var dataService = new Mock<DataService>();
var controller = new ListsController(dataService);
...
}
namespace Services
{
public class DataService
{
private readonly IKeyedRepository<int, FavList> FavListRepository;
private readonly IUnitOfWork unitOfWork;
public FavListService FavLists { get; private set; }
public DataService(IKeyedRepository<int, FavList> FavListRepository,
IUnitOfWork unitOfWork)
{
this.FavListRepository = FavListRepository;
this.unitOfWork = unitOfWork;
FavLists = new FavListService(FavListRepository);
}
public void Commit()
{
unitOfWork.Commit();
}
}
}
namespace MyListsWebsite.Controllers
{
public class ListsController : Controller
{
private readonly DataService dataService;
public ListsController(DataService dataService)
{
this.dataService = dataService;
}
public ActionResult Index()
{
var myLists = dataService.FavLists.All().ToList();
return View(myLists);
}
}
}
Create an interface like this:
public interface DataService
{
FavListService FavLists { get; }
void Commit();
}
Make your DataService implement this interface and your controller should depend on this interface. Problem solved :)
EDIT: This line of code:
dataService.FavLists.All().ToList();
is breaking the law of demeter and will be a pain to unit test your service. Create a method like AllFavList() on your service instead of all these chain of calls, it will be easier to mock.
EDIT2: How to mock you get property
dataService.SetupGet(d => d.FavLists).Returns(your_variable);
I'm using asp.net MVC 2 and Ninject 2.
The setup is very simple.
Controller calls service that calls repository.
In my controller I use inject to instantiate the service classes with no problem. But the service classes don't instantiate the repositories, giving me NullReferenceException.
public class BaseController : Controller
{
[Inject]
public IRoundService roundService { get; set; }
}
This works. But then this does not...
public class BaseService
{
[Inject]
public IRoundRepository roundRepository { get; set; }
}
Giving a NullReferenceException, when I try to use the roundRepository in my RoundService class.
IList<Round> rounds = roundRepository.GetRounds( );
Module classes -
public class ServiceModule : NinjectModule
{
public override void Load( )
{
Bind<IRoundService>( ).To<RoundService>( ).InRequestScope( );
}
}
public class RepositoryModule : NinjectModule
{
public override void Load( )
{
Bind<IRoundRepository>( ).To<RoundRepository>( ).InRequestScope( );
}
}
In global.axax.cs
protected override IKernel CreateKernel( )
{
return new StandardKernel( new ServiceModule( ),
new RepositoryModule( ) );
}
Have you thought about using constructor injection?
That's how I do my dependency injection with Ninject 2 & ASP.NET MVC 2 and it works all the way down the chain from controller -> service -> repository & beyond.
It also makes sense to me to have the dependencies in the constructor for your object. It makes these dependencies highly visible and obvious to any other object that has to instantiate it. Otherwise you may end up with null reference exceptions... kinda like you have here.
HTHs,
Charles
EDIT: Showing base class injection through constructors in response to the comments.
public class BaseService
{
public IRoundRepository RoundRepo { get; private set; }
public BaseService(IRoundRepository roundRepo)
{
RoundRepo = roundRepo;
}
}
public class SquareService : BaseService
{
public ISquareRepository SquareRepo { get; private set; }
public SquareService(ISquareRepository squareRepo, IRoundRepository roundRepo)
: base(roundRepo)
{
SquareRepo = squareRepo;
}
}
This is just my way of doing things... someone else may have a different idea / opinion.
I am trying to get my head around the sharp architecture and follow the tutorial. I am using this code:
using Bla.Core;
using System.Collections.Generic;
using Bla.Core.DataInterfaces;
using System.Web.Mvc;
using SharpArch.Core;
using SharpArch.Web;
using Bla.Web;
namespace Bla.Web.Controllers
{
public class UsersController
{
public UsersController(IUserRepository userRepository)
{
Check.Require(userRepository != null,"userRepository may not be null");
this.userRepository = userRepository;
}
public ActionResult ListStaffMembersMatching(string filter) {
List<User> matchingUsers = userRepository.FindAllMatching(filter);
return View("ListUsersMatchingFilter", matchingUsers);
}
private readonly IUserRepository userRepository;
}
}
I get this error:
The name 'View' does not exist in the current context
I have used all the correct using statements and referenced the assemblies as far as I can see. The views live in Bla.Web in this architecture.
Can anyone see the problem?
Thanks.
Christian
You should inherit UsersController from System.Web.Mvc.Controller class. View() method is defined in Controller class.
public class UsersController : Controller
{
//...
}