Question

So I have a Session variable which is set during the first user login

Session["ClientID"]

Basically this is used for theming (so the ClientID sets the theme/brand to appear on a website). Looking at the code applying

(Guid)Session["ClientID"] 

All over the place just seems dirty and error prone, what the best design pattern to use to get the variable globally recognized. So I can do

this.CurrentClientID

or something similar on all MVC Pages. In theory I could overload the Controller class with a Custom class providing this ID, but I’m not sure how I would expose this to the View as well.

Any pointers to the best solution would be gratefully received!

Answer 1

No idea what you mean globally, but an extension method to the ControllerBase class would render it accessible in all your controllers:

public static class ControllerExtensions
{
    public static Guid GetCurrentClientID(this ControllerBase controller)
    {
        return (Guid)controller.ControllerContext.HttpContext.Session["ClientID"];
    }
}

and now inside each controller you can access it:

public ActionResult Foo()
{
    Guid id = this.GetCurrentClientID();
    ...
}

And if you want it to be even more globally available make it an extension method to the HttpContextBase class:

public static class ControllerExtensions
{
    public static Guid GetCurrentClientID(this HttpContextBase context)
    {
        return (Guid)context.Session["ClientID"];
    }
}

now everywhere you have access to the HttpContext (which is pretty much everywhere in an ASP.NET application) you simply use the extension method. For example inside a view:

@Html.ActionLink("foo link", "foo", new { clientid = Context.GetCurrentClientID() })