Selection processors are a bit similar to init-processors in that their sole purpose is to do any form of processing that you need. However, these are executed after init-processors and after handler factories have loaded, but just prior to route selection. This gives you an opportunity to use the information already provided to you by the other Themelia features to alter anythign you need to alter the route selection process.

Probably the most obvious use of a mid processor is in detecting to see if the information already provided gives enough information to skip the routing selection process entirely. So, for example, based on certain security information provided to you in a custom init-processor, you may already know you need to use a specific HTTP handler.

An selection processor is made by creating a class that inherits from Themelia.Web.Processing.SelectionProcessorBase. This is an abstract class that requires you to implement the following signature:

System.Web.IHttpHandler Execute(System.Web.HttpContext context, params Object[] parameterArray)

By returning an HTTP handler, the route selection process is skipped. By returning null, everything continues as usual.