How do I format MVC Route parameters?

Question

I have the following route mapped in my test MVC3 project -

routes.MapRoute(
    "TestRoute",
    "test/{DateFrom}/{DateTo}",
    new { controller = "Home", action = "TestRoute" }
);

I am then building a link in the view as follows -

@Html.ActionLink("Test Link", "TestRoute", new
{
    DateFrom = new DateTime(2006, 02, 16),
    DateTo = new DateTime(2008, 04, 22)
})

Which when rendered, outputs this URL -

/test/02/16/2006%2000%3a00%3a00/04/22/2008%2000%3a00%3a00

As you can see, the framework has called ToString() on the DateTime parameters and then encoded the result.

I would like to format the DateTime route parameters so they are output as "yyyy-MM-dd".

Obviously I can specify the format when building the Action Link like so -

@Html.ActionLink("Test Link", "TestRoute", new
{
    DateFrom = new DateTime(2006, 02, 16).ToString("yyyy-MM-dd"),
    DateTo = new DateTime(2008, 04, 22).ToString("yyyy-MM-dd")
})

However we know this is messy, cumbersome and not DRY.

I have tried using [DisplayFormat(DataFormatString = "{0:dd-MM-yyyy}")] attribute on the properties in the model hoping this was the answer, however it seems these are only respected when building editor forms.

FYI, if I manually type the DateTime parameters in the URL in my browser (e.g. /test/2006-02-16/2008-04-22) the parameters are correctly parsed, so it's just a case of getting them formatted how I want.

Answer 1

You could write a custom helper to handle links that have dates:

namespace System.Web.Mvc {
    public static class LinkExtensions {
        public static MvcHtmlString DateLink(this HtmlHelper htmlHelper, string linkText, string actionName) {
            return DateLink(htmlHelper, linkText, actionName, new RouteValueDictionary(), null);
        }
        public static MvcHtmlString DateLink(this HtmlHelper htmlHelper, string linkText, string actionName, object routeValues) {
            return DateLink(htmlHelper, linkText, actionName, new RouteValueDictionary(routeValues), new RouteValueDictionary());
        }
        public static MvcHtmlString DateLink(this HtmlHelper htmlHelper, string linkText, string actionName, object routeValues, object htmlAttributes) {
            return DateLink(htmlHelper, linkText, actionName, new RouteValueDictionary(routeValues), HtmlHelper.AnonymousObjectToHtmlAttributes(htmlAttributes));
        }
        public static MvcHtmlString DateLink(this HtmlHelper htmlHelper, string linkText, string actionName, RouteValueDictionary routeValues) {
            return DateLink(htmlHelper, linkText, actionName, routeValues, new RouteValueDictionary());
        }
        public static MvcHtmlString DateLink(this HtmlHelper htmlHelper, string linkText, string actionName, RouteValueDictionary routeValues, IDictionary<string, object> htmlAttributes) {
            if (String.IsNullOrEmpty(linkText)) {
                throw new ArgumentException("linkText");
            }


            //check additional parameters
            List<string> keys = new List<string>(routeValues.Keys);
            foreach (string key in keys) {
                 if (routeValues[key].GetType() == typeof(DateTime))
                      routeValues[key] = ((DateTime)routeValues[key]).ToString("yyyy-MM-dd");
            }

            return MvcHtmlString.Create(HtmlHelper.GenerateLink(htmlHelper.ViewContext.RequestContext,
                htmlHelper.RouteCollection, linkText, null, actionName, (string)routeValues["controller"], routeValues, htmlAttributes));
        }
    }

And then you could use it like so:

@Html.DateLink("TestLink", "Details", new { starttime = new DateTime(2011, 1, 1), endtime = new DateTime(2012, 1, 1)})

Which produces the following URL:

http://localhost/MyController/Details/2011-01-01/2012-01-01