Use session state for an ApiController - asp.net-mvc-4

Question

I want to have my own AppContext in my ApiController (MVC4).
Should be something like
public class TestController : BaseApiController
{
[HttpGet]
public IEnumerable<TestVM> GetAll()
{
// the test service is injected with SimpleInjector
return _testService.GetAll(**base.AppContext**);
}
}
but the ApiController haven't access to the Session.
Are there any solutions to "activate" the Session for specific keys (because I don't want the whole Session)?
Or do you have any other idea (cache or cookie)?
This is the BaseApiController
public abstract class BaseApiController: ApiController
{
public IAppContext AppContext
{
get { return SessionState.AppContext; }
}
}
and this is my IAppContext (it will have more properties in the future)
public interface IAppContext
{
IIdentity User { get; }
/// <summary> Gets the user id. </summary>
/// <value>The user id.</value>
int IdUser { get; }
}
here the application module which is registered in the web.config
public class ApplicationModule : IHttpModule
{
// ...
SessionState.AppContext = _appContext.InitializeNew(
HttpRuntime.AppDomainAppPath, languages);
// ...
}
SessionState class to get the AppContext
public class SessionState : BaseSessionVariables
{
public static IAppContext AppContext
{
get { return SessionState.Get<IAppContext>("AppContext"); }
set { SessionState.Set("AppContext", value); }
}
}
here the BaseSessionVariables class
public static HttpSessionState GetSession()
{
return HttpContext.Current.Session;
}
protected static T Get<T>(string key) where T : class
{
var session = BaseSessionVariables.GetSession();
if (session == null)
{
throw new Exception("No session");
}
return (session[key] as T);
}
Thanks for your help!

Answer 1

Take a look at the implementation below. It should get you headed in the right direction.
Updated IAppContext - Added Setters
public interface IAppContext
{
IIdentity User { get; set; }
/// <summary> Gets the user id. </summary>
/// <value>The user id.</value>
int IdUser { get; set; }
}
Updated Base Controller - Instantiates a new AppContextImplemenation in the OnActionExecuting method
public abstract class BaseApiController: ApiController
{
public IAppContext AppContext {get; set;}
protected override void OnActionExecuting(
ActionExecutingContext filterContext)
{
AppContext = new AppContextImplementation();
}
}
New Class - implements IAppContext and wraps the HttpContext Session. For testing you can then create an TestAppContextImplementation that doesn't rely on Session but some other in memory storage mechanism.
public class AppContextImplementation : IAppContext
{
public IIdentity User
{
get { return HttpContext.Current.Session["User"] as IIdentity; }
set { HttpContext.Current.Session["User"] = value; }
}
int IdUser
{
get { return Convert.ToInt32(Session["IdUser"]); }
set { Session["IdUser"] = value; }
}
}

Answer 2

For ApiControllers, build yourself a DelegatingHandler and push all of your goodies onto request.Properties. You can then retrieve them from your request whether you are testing or running live. The benefit is that you then have zero dependency on Session in your Controller.
MessageHandler
public class ContextHandler : DelegatingHandler
{
protected override Task<HttpResponseMessage> SendAsync(HttpRequestMessage request, System.Threading.CancellationToken cancellationToken)
{
// get the goodies to add onto the request
var goodies = /* call to goodieGoodieYumYum */
// add our goodies onto the request
request.Properties.Add(Constants.RequestKey_Goodies, goodies);
// pass along to the next handler
return base.SendAsync(request, cancellationToken);
}
}
Controller Action
var goodies = (List<Goodie>)Request.Properties[Constants.RequestKey_Goodies];