Journey of a Software Developer

Some time ago, I read an article on how to detect a session timeout in a ASP.Net Web forms application by placing some code in a Base Page. The code worked for me and you could read more about it here.  In my last post I mentioned that Microsoft released a beta version of their MVC implementation of ASP.Net and since them, I have been playing around with it. But, as with Web forms, I still needed a way to detect a session timeout and perform an action when a timeout is detected. So, I decided to use the same code implemented in the original article and implement it into my MVC project. I decided to write a custom action filter and apply it to my controller actions where I need to ensure that my session was still active. Here is the code for my action filter.

using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.Mvc;
using System.Reflection;

namespace Web {

    public class SessionExpireFilterAttribute : ActionFilterAttribute {

        public override void OnActionExecuting( ActionExecutingContext filterContext ) {
            HttpContext ctx = HttpContext.Current;

            // check if session is supported
            if ( ctx.Session != null ) {

                // check if a new session id was generated
                if ( ctx.Session.IsNewSession ) {

                    // If it says it is a new session, but an existing cookie exists, then it must
                    // have timed out
                    string sessionCookie = ctx.Request.Headers[ "Cookie" ];
                    if ( ( null != sessionCookie ) && ( sessionCookie.IndexOf ( "ASP.NET_SessionId" ) >= 0 ) ) {

                        ctx.Response.Redirect ( "~/Home/Login" );
                    }
                }
            }

            base.OnActionExecuting ( filterContext );
        }
    }
}

And then, I would apply this filter to my Controller action methods like so:

using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.Mvc;
using System.Web.Mvc.Ajax;

namespace Web.Controllers {

    public class HomeController : Controller {

        [SessionExpireFilter]
        public ActionResult Index( ) {
            // This method will not execute if our session has expired

            // render Home Page
            return View();
        }

        public ActionResult Login() {
            // render Login page
            return View();
        }
    }
}

The code is pretty straightforward. I just apply the [SessionExpireFilter] attribute on each method where I want to ensure that our session is still valid. If you have any questions, leave a comment under this post. Until next time…

Happy Coding!

Scott Gu has all the details.  I’ve been waiting for the beta release before I really started digging into this MVC framework.  I am a Web Forms guy; but I have been waiting for a “structured framework” to come instead of dropping controls on a page and writing UI code behind each page. Based on all of the reading that I have seen, I like what I see.

For a purely web forms developer, which I am not, don’t expect to get all the fancy controls like GridViews, Validation controls, Login Controls, etc, like you would get out of the box in a web forms project. With ASP.NET MVC, HTML is your friend and if you are intimidated by writing HTML, then you probably shouldn’t be a web developer in the first place. However, this is the concept of HTML Helpers that you can use to assist you in generating pretty much all of the HTML input controls just by using some script code; but it is not mandatory. 

So, this will be a breath of fresh air for me. I am working on a  project now and I will be developing it using the MVC framework. I like working with new stuff and hopefully I will be able to share my experience as I go along. Until next time…

Happy Coding!