Apply session state behavior per action in Asp.Net MVC

Last week after I read an interesting article: Parallel processing of concurrent Ajax requests in Asp.Net MVC I created a small mvc project and started to fool around with all kind of combinations between SessionStateAttribute and parallel Ajax requests and everything went well, it was exactly the behavior described in the blog article i've mentioned. After that I was curious what is the default behavior regarding session locking when no SessionStateAttribute is present and made some tests from which i obtained the following results: When a new session is created and there was no write operations performed on it, then requests are treated the same as in case of using SessionStateBehavior.ReadOnly, but after first write action on the session, all the following request are processed in SessionStateBehavior.Required mode which is equivalent with “good bye parallel request execution”, of course we can to impose a custom session state behavior by applying SessionStateAttribute on controller, but that mean that all actions from that controller will have the same session state behavior which in most cases is not a problem, but what if I have to write and read from a session, and from the same controller I want to execute some actions in parallel which has nothing to do with session, what solutions do I have for this scenario? Of course I can move all my parallel actions into different controller and change it session state behavior, but wouldn’t it be nice if I had an attribute which will permit to change session state behavior per action, and since there is no such attribute in .Net framework by default, I made a custom one.

Next I’ll show you how to create and use this custom attribute.

1 Create custom attribute class

 
    [AttributeUsage(AttributeTargets.Method, AllowMultiple = false, Inherited = true)]
    public sealed class ActionSessionStateAttribute : Attribute
    {
        public SessionStateBehavior Behavior { get; private set; }

        public ActionSessionStateAttribute(SessionStateBehavior behavior)
        {
            this.Behavior = behavior;
        }
    }

2 Create/Modify custom controller factory


public class CustomControllerFactory : DefaultControllerFactory
    {
        protected override SessionStateBehavior GetControllerSessionBehavior(RequestContext requestContext, Type controllerType)
        {
            if (controllerType == null)
            {
                return SessionStateBehavior.Default;
            }

            var actionName = requestContext.RouteData.Values["action"].ToString();
            MethodInfo actionMethodInfo;

            try
            {
                actionMethodInfo = controllerType.GetMethod(actionName, BindingFlags.IgnoreCase | BindingFlags.Public | BindingFlags.Instance);
            }
            catch (AmbiguousMatchException matchExc)
            {
                var httpRequestTypeAttr =
                    requestContext.HttpContext.Request.RequestType.Equals("POST")
                        ? typeof(HttpPostAttribute)
                        : typeof(HttpGetAttribute);

                actionMethodInfo =
                    controllerType.GetMethods().FirstOrDefault(
                        mi =>
                        mi.Name.Equals(actionName, StringComparison.CurrentCultureIgnoreCase) && mi.GetCustomAttributes(httpRequestTypeAttr, false).Length > 0);
            }


            if (actionMethodInfo != null)
            {
                var actionSessionStateAttr = actionMethodInfo.GetCustomAttributes(typeof(ActionSessionStateAttribute), false)
                                 .OfType<ActionSessionStateAttribute>()
                                 .FirstOrDefault();

                if (actionSessionStateAttr != null)
                {
                    return actionSessionStateAttr.Behavior;
                }
            }

            return base.GetControllerSessionBehavior(requestContext, controllerType);

        }
    }

3 Confiugre MVC to use your custom controller factory

In Global.asax you should add the following code:


 protected void Application_Start()
        {
            ControllerBuilder.Current.SetControllerFactory(typeof(CustomControllerFactory));
        }

Example of attribute usage:


        [ActionSessionState(SessionStateBehavior.Disabled)]
        public JsonResult Test(int id)
        {
            Thread.Sleep(8000);
            return Json("I've slept 8 sec.");
        }

You can use ActionSessionStateAttribute in combination with the controller attribute SessionStateAttribute, in this case ActionSessionStateAttribute overrides controller attribute on the actions to which it was applied.

mvc c# asp.net
Posted by: Ion Sapoval
Last revised: 29 Nov, 2013 02:05 PM