Intercept Page object creation to hook up events

Question

I'm looking for a way to intercept the ASP.NET processing pipeline in such a way to be able to register event handlers to all events on the Page class. The reason is, I need to maintain a session-bound instance of a component that needs to be notified of all important Page events, starting from OnPreInit.

There's an arbitrary number of Page descendants in the application, which are not under my control. Hence I cannot use an approach like using a single custom descendant, that would notify the session-bound component, as a base class for all pages in the web application.

I don't think creating a custom IHttpHandler or IHttpModule implementation would solve the problem. Also note I cannot create a custom HttpApplication descendant.

Answer 1

It isn't going to be an elegant process to do what you are looking at, especially if you need to handle multiple page events, but in theory it is fully possible from within the Global.asax to setup handlers that you need for each and every page.

The trick here is to add your code to the global.asax in the PreRequestHandlerExecute method, from here you can get access to the HttpApplication object, get access to the page from there, and then register your events. This process is necessary as a new page instance is created for every page that is processed.

Now, other options as you know are far more elegant, but this should get to where you need to be. One helpful tutorial I found although around Themeing shows you the whole process here.

EDIT:

After seeing your comment, yes, you can simply do what I'm stating above, in a custom HttpModule. The article I linked even shows you that process :)

Answer 2

Without knowing more about what you're trying to accomplish it really sounds like you do indeed want to create a http module or handler. You might want to take a look at this question