Can abstract class be a parameter in a controller's action?

Question

I have an Action function inside of a Controller, which is being called with AJAX. That Action is taking in 1 parameter. Client side, I construct a JSON object which shoul

Answer 1

Update: Example now uses a AJAX JSON POST

If you must use an abstract type, you could provide a custom model binder to create the concrete instance. An example is shown below:

Model / Model Binder

public abstract class Student
{
    public abstract int Age { get; set; }
    public abstract string Name { get; set; }
}
public class GoodStudent : Student
{
    public override int Age { get; set; }
    public override string Name { get; set; }
}
public class BadStudent : Student
{
    public override int Age { get; set; }
    public override string Name { get; set; }
}
public class StudentBinder : IModelBinder
{
    public object BindModel(ControllerContext controllerContext, ModelBindingContext bindingContext)
    {
        var values = (ValueProviderCollection) bindingContext.ValueProvider;
        var age = (int) values.GetValue("Age").ConvertTo(typeof (int));
        var name = (string) values.GetValue("Name").ConvertTo(typeof(string));
        return age > 10 ? (Student) new GoodStudent { Age = age, Name = name } : new BadStudent { Age = age, Name = name };
    }
}

Controller Actions

public ActionResult Index()
{
    return View(new GoodStudent { Age = 13, Name = "John Smith" });
}
[HttpPost]
public ActionResult Index(Student student)
{
    return View(student);
}

View

@model AbstractTest.Models.Student

@using (Html.BeginForm())
{
    

        
Age @Html.TextBoxFor(m => m.Age)
        
Name @Html.TextBoxFor(m => m.Name)
        

    
}

Added to Global.asax.cs

protected void Application_Start()
{
    ...
    ModelBinders.Binders.Add(new KeyValuePair(typeof(Student), new StudentBinder()));
}