Hallo,

first I want to say that I hope this doesn't look like I am lazy but I have some trouble understanding a piece of code from the following project.

http://kigg.codeplex.com/

I was going through the source code and I noticed something that would be usefull for my own little project I am making. In their BaseController they have the following code:

private static readonly Type CurrentUserKey = typeof(IUser);

public IUser CurrentUser
{
    get
    {
        if (!string.IsNullOrEmpty(CurrentUserName))
        {
            IUser user = HttpContext.Items[CurrentUserKey] as IUser;

            if (user == null)
            {
                user = AccountRepository.FindByClaim(CurrentUserName);

                if (user != null) 
                {
                    HttpContext.Items[CurrentUserKey] = user; 
                }
            }

            return user;
        }

        return null;
    }
}

This isn't an exact copy of the code I adjusted it a little to my needs. This part of the code I still understand. They store their IUser in HttpContext.Items. I guess they do it so that they don't have to call the database eachtime they need the User object.

The part that I don't understand is how they maintain this object in between requests. If I understand correctly the HttpContext.Items is a per request cache storage.

So after some more digging I found the following code.

internal static IDictionary<UnityPerWebRequestLifetimeManager, object> GetInstances(HttpContextBase httpContext)
{
    IDictionary<UnityPerWebRequestLifetimeManager, object> instances;

    if (httpContext.Items.Contains(Key))
    {
        instances = (IDictionary<UnityPerWebRequestLifetimeManager, object>) httpContext.Items[Key];
    }
    else
    {
        lock (httpContext.Items)
        {
            if (httpContext.Items.Contains(Key))
            {
                instances = (IDictionary<UnityPerWebRequestLifetimeManager, object>) httpContext.Items[Key];
            }
            else
            {
                instances = new Dictionary<UnityPerWebRequestLifetimeManager, object>();
                httpContext.Items.Add(Key, instances);
            }
        }
    }

    return instances;
}

This is the part where some magic happens that I don't understand. I think they use Unity to do some dependency injection on each request? In my project I am using Ninject and I am wondering how I can get the same result.

I guess InRequestScope in Ninject is the same as UnityPerWebRequestLifetimeManager? I am also wondering which class/method they are binding to which interface? Since the HttpContext.Items get destroyed each request how do they prevent losing their user object?

Anyway it's kinda a long question so I am gradefull for any push in the right direction.

Kind regards,

Pickels