Initializing abstract class object using dependency injection

Question

I am inheriting ApiController and below is my overridden ExecuteAsync method with dependency injection,

public abstract class BaseController : ApiController
{
    private IMyService _myService;
    public PersonModel person;
    protected BaseController(IMyService myService)
    {
        _myService = myService;
    }

    public override Task<HttpResponseMessage> ExecuteAsync(HttpControllerContext controllerContext, CancellationToken cancellationToken)
    {
        _myService.Initialize(person);
    }
}

This is my service interface,

public interface IMyService 
{
    HttpResponseMessage Initialize(PersonModel person);
}

Here is the class,

public class MyService : IMyService
{
    public HttpResponseMessage Initialize(PersonModel person)
    {
        //Initializing person model from db
        return new HttpResponseMessage(HttpStatusCode.OK);
    }
}

When I execute this method, person object in the BaseController class is still null. What should I change to initialize the object in abstract class?

I'm guessing you're doing something along the lines of `person = new PersonModel()` inside `Initialize`. That won't work at all. You'll need it to *return* a person model, or (an ugly workaround), use `ref`. — Rob, Jul 14 '17 at 04:07
You initialize an application component (`IMyService`) with runtime data (`PersonModel`). [This is anti-pattern](https://www.cuttingedge.it/blogs/steven/pivot/entry.php?id=99). — Steven, Jul 14 '17 at 07:04
Simply put, [*never* use a base class in MVC or WebApi when using DI](https://stackoverflow.com/a/6119341/181087). This can be solved in a DI-friendly way by using a [global filter](https://stackoverflow.com/a/9521363) to initialize your data. — NightOwl888, Jul 14 '17 at 19:00

score -1 · Answer 1 · answered Jul 14 '17 at 04:20

-1

Please check this thread to see if this answers your question - Registering implementations of base class with Autofac to pass in via IEnumerable

You will have to register the child classes of your abstract class appropriately.

answered Jul 14 '17 at 04:20

ArunGeorge

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Initializing abstract class object using dependency injection

1 Answers1