Track your visitors using an HttpModule
I’ve been thinking about how to solve a very simple problem on a website: visitor behaviour tracking. In a sense it is what Google Analytics does, but there are problems with conventional JavaScript based trackers.
They are good at tracking page views, but very bad at tracking actions or behaviour around a website. Some products like Headlight are actually pretty good at tracking actions such as button clicks etc, but at the level I’m interested in tracking, I would have to add JavaScript all over my page. I don’t want to do that.
Also, there are some very good server-side logging products like log4net out there. The problem is that they are not really meant for tracking website behaviour with URLs, user agents and other important metadata.
What I want is a combination of the traditional JavaScript- and server-side methods. So, I’ve played around with a custom HttpModule that logs all page views and custom actions. You add the custom actions yourself by calling VistorLog.AddAction("message", "type"). That way you have page views and actions in a chronologically correct order.
A neat thing is that all page views and actions are kept in session and only when the session expires does it write to the database. That way it can do a batch insert which is much faster than hitting the database constantly. Another neat thing is that the HttpModule is only 100 lines of code.
The code
Basically, three things are going on. The session starts and we add a Visit object to it.
void session_Start(object sender, EventArgs e)
{
HttpContext context = HttpContext.Current;
Visit visit = new Visit();
visit.UserAgent = context.Request.UserAgent;
visit.IpAddress = context.Request.UserHostAddress;
context.Session.Add("visit", visit);
}
Then every page view is registered after an .aspx page is served.
void context_PostRequestHandlerExecute(object sender, EventArgs e)
{
HttpContext context = ((HttpApplication)sender).Context;
if (context.CurrentHandler is Page)
{
Visit visit = context.Session["visit"] as Visit;
if (visit != null)
{
Action action = new Action();
action.Url = context.Request.Url;
action.Type = "pageview";
visit.Action.Add(action);
}
}
}
Then the session ends and we need to store the visitor log.
void session_End(object sender, EventArgs e)
{
HttpContext context = HttpContext.Current;
Visit visit = context.Session["visit"] as Visit;
if (visit != null)
{
// Log the Visit object to a database
}
}
Implementation
When you have registered the HttpModule in the web.config, then it starts collection page views in the session. To store them in a database you must add your own code to the session_End method of the module. Now you are also able to store actions just by calling a static method on the VisitorLog module:
VisitorLog.AddAction("Profile picture deleted", "deletion");
Keep in mind that this code is just me playing around in my sandbox. It has never been in a production environment.