.NET MVC 4 - Multiple "actions" on same Controller, how?

Question

I'm pulling my hair out over this one and I'm looking for guidance before I start fudging together my own approach.

Here's what I've got:

View snippet

<td>@Html.ActionLink("More Details", "Index", new { id = product.ProductId })</td>
<td>@Html.ActionLink("Compare", "Compare", new { id = product.ProductId, compare = true })</td>

Controller snippet

public ActionResult Index(FormCollection values)
{
    // Does stuff, works
}

public ActionResult Index(int productId)
{
    // Does stuff, works
}

Now, here lies my problem. The Index functions are both taken now, from the POST to the form, and the "More Details" ActionLink being clicked. This works fine.

Now I want "Compare" to be functional, in which I want on the same page and will hold a list of compared products, which is fine. But how do I get that Compare functionality on the same View/Page?!

I've tried:

public ActionResult Compare(int productId)
{

}

But obviously that doesn't work as it requires a Compare.cshtml, which I don't want to happen. I want it to be modify my ViewModel and return it with newly Compared products, so I'd be able to do this from my original View:

@foreach(var products in Model.ComparedProducts)

The only way I can see me doing this is "fudging it" to have:

public ActionResult Index(int productId = 0, bool compare)
{

}

Which could become unruly with lots of functionality on the same page.

Surely there's something obvious I'm missing here?

Oh, and the AjaxLink options isn't right for me, as this is part of the site that has to work via postbacks (Progress Enhancement and all that jazz).

Answer 1

I think you return an ActionResult by calling return View(model), is that right? Without naming a view explicitly, the MVC resolving mechanism looks for views with the same name as the action, in your case "Compare.cshtml".

If you change your call to return View("Index", model) you will be using the Index.cshtml view regardless of the action name.

Is that what you were looking for?

Answer 2

An action in MVC does not require a corresponding View. It can return any view by supplying a name parameter to the View() function - see http://msdn.microsoft.com/en-us/library/system.web.mvc.controller.view%28v=vs.98%29.aspx for details.

You can in your compare function do all the logic required and redirect back to the index action or any other that display the page as needed using RedirectToAction().