c# - Passing data to Master Page in ASP.NET MVC

Question

What is your way of passing data to Master Page (using ASP.NET MVC) without breaking MVC rules?

Personally, I prefer to code abstract controller (base controller) or base class which is passed to all views.

Answer 1

If you prefer your views to have strongly typed view data classes this might work for you. Other solutions are probably more correct but this is a nice balance between design and practicality IMHO.

The master page takes a strongly typed view data class containing only information relevant to it:

public class MasterViewData
{
    public ICollection<string> Navigation { get; set; }
}

Each view using that master page takes a strongly typed view data class containing its information and deriving from the master pages view data:

public class IndexViewData : MasterViewData
{
    public string Name { get; set; }
    public float Price { get; set; }
}

Since I don't want individual controllers to know anything about putting together the master pages data I encapsulate that logic into a factory which is passed to each controller:

public interface IViewDataFactory
{
    T Create<T>()
        where T : MasterViewData, new()
}

public class ProductController : Controller
{
    public ProductController(IViewDataFactory viewDataFactory)
    ...

    public ActionResult Index()
    {
        var viewData = viewDataFactory.Create<ProductViewData>();

        viewData.Name = "My product";
        viewData.Price = 9.95;

        return View("Index", viewData);
    }
}

Inheritance matches the master to view relationship well but when it comes to rendering partials / user controls I will compose their view data into the pages view data, e.g.

public class IndexViewData : MasterViewData
{
    public string Name { get; set; }
    public float Price { get; set; }
    public SubViewData SubViewData { get; set; }
}

<% Html.RenderPartial("Sub", Model.SubViewData); %>

This is example code only and is not intended to compile as is. Designed for ASP.Net MVC 1.0.