PrimeDigit – A Design Blog by Will Shaver

JQuery In Action:
347 Pages, not a single mention of the queue() method.

To be fair, they do mention “mainaining state”. (sic)

ICANN RFC for anything.* domain names. Might want to take a look. Most of you readers play in this here internets thing, this could effect you or the company you work for. :)

For future reference for myself and others:

1. CustomModelBinderAttribute -> GetBinder()
2. IModelBinder -> BindModel()
3. ActionFilterAttribute -> OnActionExecuting()
4. ActionFilterAttribute -> OnActionExecuted()
5. ActionFilterAttribute -> OnResultExecuting()
6. ActionFilterAttribute -> OnResultExecuted()

(As of Beta 1)

The recently released MVC Beta 1 has some pretty cool features. One of the features that I’ve been using for a while is Model Binders. These are now turned on by default which can cause some problems if you’re not expecting this behavior. For example, say you have an action as follows:

        public ActionResult Binder(Dog dog)

        {

            return View("Index");

        }

Here’s the model:

    public class Dog

    {

        public string Name { get; set; }

        public Dog cat { get; set; }

    }

Calling this action will cause a stack overflow error, as the default model binder will attempt to recreate every dog in the chain.

I would not have noticed this as I use my own implementation of the model binders to provide functionality for pulling an entity from NHibernate that is passed by ID via Ajax. The problem is that I recently switched over to the [Transaction]/ATM method of managing transactions with NHibernate. The problem with this method is that it creates a dynamic proxy of your controller so it can intercept the transaction. In doing so it looses the method argument attributes and then – boom – stack overflow. So now I’m off to hack YET ANOTHER open source project to see if I can get it to not remove the method parameter attributes. :(

Sometimes it is useful to create a cache specific to a particular session. I use this for pre-NH cache in my repositories that I can query with Linq before hitting NH sometimes. You could easily modify this to not be templated and instead work for any object…

If you think there is something wrong with this approach please let me know. :)

public class SessionCache<T>

    {

        private ISession sn;

        private IList<T> entities;

        private void ValidateSession(ISession session)

        {

            if(sn == session)

                return;

            sn = session;

            entities = new List<T>();

        }

        public void Add(ISession session, params T [] entity)

        {

            ValidateSession(session);

            foreach (T t in entity)

            {

                if(!Equals(t, default(T)) && !entities.Contains(t))

                    entities.Add(t);

            }

        }

        public void Remove(T entity, ISession session)

        {

            ValidateSession(session);

            if(entities.Contains(entity))

                entities.Remove(entity);

        }

        public T[] GetEntities(ISession session)

        {

            ValidateSession(session);

            return entities.ToArray();

        }

        public void Clear()

        {

            if(entities != null)

                entities.Clear();

        }

    }

Looks like the bits were changed some for preview 5 around the action filters. The ‘Cancel’ property was removed from the ActionExecutingContext. It looks like for my purposes I can use IAuthorizationFilter and FilterAttribute to get at an AuthorizationContext which has the cancel attribute.