ASP.NET MVC TempData in browser cookie

Question

I am trying to use a custom ITempDataProvider provider to store TempData in a browser\'s cookie instead of session state. However, everythi

Answer 1

Here is an example of a working solution without lots of excess code. It uses Json.NET for serializing, which is faster than BinaryFormatter + Base64Encoding and also produces a much shorter string (=less http overhead).

public class CookieTempDataProvider : ITempDataProvider
{
    const string cookieKey = "temp";

    public IDictionary LoadTempData(ControllerContext controllerContext)
    {
        var cookie = controllerContext.HttpContext.Request.Cookies[cookieKey];   

        if (cookie != null) {
            return JsonConvert.DeserializeObject>(cookie.Value);
        }

        return null;
    }

    // Method is called after action execution. The dictionary mirrors the contents of TempData.
    // If there are any values in the dictionary, save it in a cookie. If the dictionary is empty,
    // remove the cookie if it exists.
    public void SaveTempData(ControllerContext controllerContext, IDictionary values)
    {
        var ctx = controllerContext.HttpContext;

        if (values.Count > 0) {
            var cookie = new HttpCookie(cookieKey)
            {
                HttpOnly = true,
                Value = JsonConvert.SerializeObject(values)
            };

            ctx.Response.Cookies.Add(cookie);
        } else if (ctx.Request.Cookies[cookieKey] != null) {

            // Expire cookie to remove it from browser.
            ctx.Response.Cookies[cookieKey].Expires = DateTime.Today.AddDays(-1);
        }
    }
}