Passing data to Master Page in ASP.NET MVC

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.