I am trying to customize a vended product that routes all requests through a HttpHandler. The handler analyzes the request to figure out what page to route the user to and performs a Server.Transfer(). Unfortunately, I need to access SessionState on a page and the handler doesn't implement IRequiresSessionState and is marked as internal so I can't inherit from it. After a lot of googling the best solution I found was to create an HttpModule that changes the handler that processes the request at different points in the request lifecycle. On PostMapRequestHandler I would change the handler that processes the request to my own that implements IRequiresSessionState and PostAcquireRequestState I would map it back.
This works but does anyone have a better solution?
I figured out a more elegant way to enable session state. You can override the session state behavior of a handler. I created a module that forces session state.
public class SessionEnablerModule : IHttpModule
{
public void Dispose()
{
}
public void Init(HttpApplication context)
{
context.PostMapRequestHandler += new EventHandler(context_PostMapRequestHandler);
}
void context_PostMapRequestHandler(object sender, EventArgs e)
{
HttpApplication app = (HttpApplication)sender;
if ((app.Context.Handler.GetType().ToString().Equals("Handler I want to enable session state for")))
{
//enable session state
app.Context.SetSessionStateBehavior(SessionStateBehavior.Required);
}
}
}
Another solution could be to route all request through your handler that requires session state and then pass those requests to internal handler by invoking its ProcessRequest method - you can create the instance of internal handler by using say Reflection (or using handler factory if any).
However, using HttpModule to swap handlers is definitely a better solution. Because you can choose to swap the handler selectively by looking at the requested URL. That way, you may not have to load/save session state for all requests (that can be expensive operation for out-of-proc sessions)
