vibed.web.auth framework and redirection

[Johannes Loher via Digitalmars-d-learn]

Hello

I'd like to use the vibed.web.auth framework for authentication 
in my vibe.d app. If a user is not authorized to access a certain 
page, he should be redirected to another page (a custom error 
page for example, or the login page in my case). At the moment, 
I'm using the following authenticate method to achieve this:

@noRoute AuthInfo authenticate(scope HTTPServerRequest req, scope 
HTTPServerResponse res)
{
     if (!req.session || !req.session.isKeySet("auth"))
     {
         redirect("/login");
         throw new HTTPStatusException(HTTPStatus.forbidden, "Du 
musst dich erst einloggen");
     }
     return req.session.get!AuthInfo("auth");
}

If you need a full working example, the complete sourcecode can 
be found at 
https://git.f3l.de/fsimphy/calendar-webapp/tree/poodinis-mongo. 
The authenticate method is in the file source/calendarwebapp.d.

While this method seems to work, there are a few issues:
1. Nothing at all seems to happen with the thrown exception 
(well, something got to happen, what is it?). I'd like to somehow 
use and display the Exception msg.
2. Using authenticate methods, which are not @safe or @trusted is 
deprecated as of vibed 0.8.0. The redirect function is neither 
@safe nor @trusted, so my authenticate method can not be @safe. I 
don't know if it is safe to mark it as @trusted.

To me, it seems as if redirecting is not really intended. This 
leads me to the question: Is there any better way to do this?

Thanks in advance for your help!