cookies.cs

using System;
using System.Web;

public class Cookies
{
    private const string ApplicationName = "MyCoolApplication";

    private enum CookieItem
    {
        UserGuid,
        UserFullName,
        UserLoginExpiry,
        UserHadForBreakfast,
        UserTimezone
    }

    // All cookie values are accessible by public  static  methods. 
    // No typos/duplicates are possible from calling code!

    public static string UserFullName
    {
        get { return GetCookieVal(CookieItem.UserFullName); }
        set { UpdateCookieVal(CookieItem.UserFullName, value, 365); }
    }

    public static  Guid UserGuid
    {
        get { return new Guid(GetCookieVal(CookieItem.UserGuid)); }
        set { UpdateCookieVal(CookieItem.UserGuid, value.ToString(), 365); }
    }

    public static  DateTime UserLoginExpiry
    {
        get { return DateTime.Parse(GetCookieVal(CookieItem.UserLoginExpiry)); }
        set { UpdateCookieVal(CookieItem.UserLoginExpiry, value.ToString(), 365); }
    }

    public static string UserHadForBreakfast
    {
        get { return GetCookieVal(CookieItem.UserHadForBreakfast); }
        set { UpdateCookieVal(CookieItem.UserHadForBreakfast, value, 1); }
    }

    private static string GetCookieVal(CookieItem item)
    {
        HttpCookie cookie = GetAppCookie(false); //get the existing cookie
        return (cookie != null && (cookie.Values[item.ToString()] != null)) //value or empty if doesn't exist
            ? cookie.Values[item.ToString()]
            : string.Empty;
    }

    private static void UpdateCookieVal(CookieItem item, string val, int expireDays)
    {
        //get the existing cookie (or new if not exists)
        HttpCookie cookie = GetAppCookie(true);

        //modify its contents & meta.
        cookie.Expires = DateTime.Now.AddDays(expireDays);
        cookie.Values[item.ToString()] = val;

        //add back to the http response to send back to the browser
        HttpContext.Current.Response.Cookies.Add(cookie);
    }

    private static  HttpCookie GetAppCookie(bool createIfDoesntExist)
    {
        //get the cookie or a new one if indicated
        return HttpContext.Current.Request.Cookies[ApplicationName] 
        ?? ((createIfDoesntExist) ? new HttpCookie(ApplicationName) : null);
    }
}