ASP.NET MVC Session usage

Just thought I would share how I am using session in my application. I really like this implementation (Suggestions for Accessing ASP.NET MVC Session[] Data in Controllers and Extension Methods?) of using session as it makes it easy to swap out session for another store or for testing purposes.

Looking at the implementation it reminded me of the ObjectStore I have used in other projects to serialize objects as binary or xml and store in a database or on the filesystem.

I therefore simplified my interface (previously T had to be a class) and came up with the following:

public interface IObjectStore {
    void Delete(string key);
    T Get<T>(string key);
    void Store<T>(string key, T value);
    IList<T> GetList<T>(string key);
}

And my session store implementation:

public class SessionStore : IObjectStore
{      
    public void Delete(string key) {
        HttpContext.Current.Session.Remove(key);
    }

    public T Get<T>(string key) {
        return (T)HttpContext.Current.Session[key];
    }

    public void Store<T>(string key, T value) {
        HttpContext.Current.Session[key] = value;
    }

    public IList<T> GetList<T>(string key) {
        throw new NotImplementedException();
    }
}

I then take in an IObjectStore in my base controller's constructor and can then use it like so to expose properties to my other controllers:

   public string CurrentCustomer {
        get {
            string currentCustomer = 
                sessionStore.Get<string>(SessionKeys.CustomerSessionKey);
            if (currentCustomer == null) {
                currentCustomer = Guid.NewGuid().ToString();
                sessionStore.Store<string>(SessionKeys.CustomerSessionKey, currentCustomer);
            }
            return currentCustomer;               
        }
    }

Am quite pleased with this approach.

You can serialize what you wish to persist and place it in a hidden input field like ViewState in WebForms.

Here's an article that should get you started: http://weblogs.asp.net/shijuvarghese/archive/2010/03/06/persisting-model-state-in-asp-net-mvc-using-html-serialize.aspx