What is an easy way to enable Mini-profiler for a session only?

Question

I have a simple web form application that uses a masterpage.

I followed the instructions on how to get mini-profiler working. I get all the stats OK. Now I do not really know how to toggle it on or off.

I thought of using a query string and look for it Application_BeginRequest - If it is there just use the profiler the whole session.... OK- Session is not loaded at that stage and if use the Application_AcquireRequestState and a static variable it loads it many many times and the profiler does work sometimes, sometimes not and I do not know why?

The simple way I have now is.

protected void Application_BeginRequest(object sender, EventArgs e)
        {
            MiniProfiler profiler = null;

            if (Request.QueryString["p"] != null)
            {

                profiler = MiniProfiler.Start();

                using (profiler.Step("Application_BeginRequest"))
                {
                }
            }


        }

So that works ok but i have to add a query param on each request. Not good. I never used global.asax before so I am not 100% sure how it all works down there.

What is the best way I can set a variable for a pre defined time so the profiler will always load when I turn it on in a secret way?

---

Edit and solution to my problem

 protected void Application_BeginRequest(object sender, EventArgs e)
        {
            MiniProfiler profiler = null;
            if (Request.Cookies["profiler"] != null)
            {
                profiler = MiniProfiler.Start();

                using (profiler.Step("Application_BeginRequest"))
                {
                }
            }

        }

Answer 1

If you added MiniProfiler via the MiniProfiler.MVC3 package, then it adds a C# file for your convenience in configuring it: look in App_Start\MiniProfiler.cs, looking in particular at Init which has the code to decide whether to start profiling (request.IsLocal is the default)

In your case, I would suggest checking for a cookie in the start condition, and checking your more complete "am I a developer, or just someone who heard about a special cookie" in the end condition; in particular, if you call MiniProfiler.Stop(false), then all the data is discarded. Your "turn it on in a secret way" and "pre defined time" are then all achieved cheaply via the cookie, with the "am I a developer" there to make sure that it can't be abused just by setting a cookie.