Creating Reversing Value Provider

ReversingValueProvider.cs

    // in global.asax
        protected void Application_Start()
        {
            // other stuff
            ValueProviderFactories.Factories.Add(new ReverseValueProviderFactory());
        }


    public class ReverseValueProviderFactory : ValueProviderFactory
    {
        public override IValueProvider GetValueProvider(ControllerContext controllerContext)
        {
            return new ReverseValueProvider(
                from vpv in ValueProviderFactories.Factories
                    where vpv.GetType() != typeof(ReverseValueProviderFactory)
                    select vpv.GetValueProvider(controllerContext));
        }
    }

    public class ReverseValueProvider : IValueProvider
    {
        private readonly IEnumerable<IValueProvider> valueProviders;

        public ReverseValueProvider(IEnumerable<IValueProvider> valueProviders)
        {
            this.valueProviders = valueProviders;
        }

        public bool ContainsPrefix(string prefix)
        {
            return true;
        }

        public ValueProviderResult GetValue(string key)
        {
            foreach (IValueProvider valueProvider in valueProviders)
            {
                if (valueProvider != null)
                {
                    ValueProviderResult result = valueProvider.GetValue(key + "Reversed");
                    if (result != null)
                    {
                        object newRaw = result.RawValue;
                        if( result.RawValue is string[])
                        {
                            newRaw = ((string[]) result.RawValue).Select(Reverse).ToArray();                            
                        } else if(result.RawValue is string)
                            newRaw = Reverse((string) result.RawValue);

                        var providerResult = new ValueProviderResult(newRaw, Reverse(result.AttemptedValue), result.Culture);
                        return providerResult;
                    }
                }
            }
            return null;
        }

        private string Reverse(string str)
        {
            return new string(str.Reverse().ToArray());
        }
    }

    public class MyController : Controller
    {
        // requesting /My/Reverse?nameReversed=luaP => Paul

        public ActionResult Reverse(string name)
        {
            return Content(name);
        }
    }