Question

I have the following classes:

class SomethingBase 
{
    public string SharedProperty { get; set; }
}

class ChildClassOne : SomethingBase 
{
    public string SpecificPropertyOne { get; set; }
}

class ChildClassTwo : SomethingBase 
{
    public string SpecificPropertyTwo { get; set; }
}

And I have ASP.NET MVC View which has two HTML-forms. These forms are calling the same action method.
This action method should receive any of two SomethingBase class derivatives.
However, if I create single parameter like SomethingBase param, then only the SharedProperty is received. This behavior can be explained by binding mechanism of ASP.NET MVC.

To make my action method work I created the next definition:

public ActionResult(ChildClassOne param1, ChildClassTwo param2)

SharedProperty goes to both params, but specific properties are populated only for object, which was actually passed from view. It works, but I don’t think that this is the only solution.

Are there some best-practice solutions for this situation?

Answer 1

Method TryUpdateModel of Controller class make it work. However, this way is not pretty elegant.

...
public ActionResult Save(FormCollection collection)
        {
            SomethingBase model = null;
            if (collection.AllKeys.Contains("SpecificOne"))
            {
                model = new ChildOne();
                TryUpdateModel<ChildOne>((ChildOne)model, collection);
            }
            else
            {
                model = new ChildTwo();
                TryUpdateModel<ChildTwo>((ChildTwo)model, collection);
            }
...