ASP.NET MVC Default View Model Binding of cookies to custom objects - asp.net-mvc-2

Question

Does the ASP.NET MVC 2 Default View Model Binding support binding a multi-value cookie to a custom object? Before I write a custom Value Provider, I would like to be sure that the functionality didn't already exist.
So given an action like:
public ActionResult SomeAction(CustomObject foo)
where CustomObject is something like:
public class CustomObject
{
public string Name { get; set; }
public int Rank { get; set; }
}
and a cookie that is part of the request like:
foo=Name=John&Rank=10
Could I get the Default View Model Binding to map the cookie to the parameter with some clever tweaks to the naming of the cookie or cookie values like posting "foo.Name=John" and "foo.Rank=10" would do?

Answer 1

Well, there's one way to do it would be to implement IModelBinder
public class CustomObjectModelBinder : IModelBinder {
public object BindModel(ControllerContext controllerContext, ModelBindingContext bindingContext) {
HttpCookie c = controllerContext.HttpContext.Request.Cookies["foo"]
CustomObject value = new CustomObject() {
foo.Name = c.Values["Name"],
foo.Rank = c.Values["Rank"]
}
return CustomObject
}
}
Then just add this to your Application_Start()
ModelBinders.Binders.Add(typeof(CustomObject), new CustomObjectModelBinder());
you can add the cookie object to any action as far as i know and it will attempt to bind it for you

Answer 2

In the end I created something to do this. Based on the work posted by Mehdi Golchin, I created a value provider that allows this kind of binding to happen.
For those interrested, the following are the custom changes I made to Mehdi's work linked above. See the link for full details on implementation. This doesn't support binding to nested objects (e.g., Foo.Cell.X) because I didn't need that level of complexity, but it would be possible to implement with a bit of recursion.
protected virtual bool ContainsPrefix(string prefix)
{
try
{
var parts = prefix.Split(new char[] { '.' }, 2, StringSplitOptions.RemoveEmptyEntries);
switch (parts.Length)
{
case 0:
return false;
case 1:
return this._context.HttpContext.Request.Cookies.AllKeys.Contains(parts[0]);
default:
var cookie = this._context.HttpContext.Request.Cookies[parts[0]];
if (cookie == null) { return false; }
return cookie.Values.AllKeys.Contains(parts[1]);
}
}
catch (Exception ex)
{
ExceptionPolicy.HandleException(ex, "Controller Policy");
return false;
}
}
protected virtual ValueProviderResult GetValue(string key)
{
try
{
var parts = key.Split(new char[] { '.' }, 2, StringSplitOptions.RemoveEmptyEntries);
if (parts.Length < 2) { return null; }
var cookie = this._context.HttpContext.Request.Cookies[parts[0]];
if (cookie == null) { return null; }
var value = cookie.Values[parts[1]];
if (value == null) { return null; }
return new ValueProviderResult(value, value, CultureInfo.CurrentCulture);
}
catch (Exception ex)
{
ExceptionPolicy.HandleException(ex, "Controller Policy");
return null;
}
}