How do I integrate existing http.Handlers with Revel?

As shown in the concept diagram, the http.Handler is where Go hands off the user’s request for processing. Revel’s handler is extraordinarily simple – it just creates the Controller instance and passes the request to the Filter Chain.

Applications may integrate existing http.Handlers by overriding the default Handler:

func installHandlers() {
	var (
		serveMux     = http.NewServeMux()
		revelHandler = revel.Server.Handler
	)
	serveMux.Handle("/",     revelHandler)
	serveMux.Handle("/path", myHandler)
	revel.Server.Handler = serveMux
}

func init() {
	revel.OnAppStart(installHandlers)
}

What is the relationship between interceptors, filters, and modules?

1. Modules are packages that can be plugged into an application. They allow sharing of controllers, views, assets, and other code between multiple Revel applications (or from third-party sources).

2. Filters are functions that may be hooked into the request processing pipeline. They generally apply to the application as a whole and handle technical concerns, orthogonal to application logic.

3. Interceptors are a convenient way to package data and behavior, since embedding a type imports its interceptors and fields. This makes interceptors useful for things like verifying the login cookie and saving that information into a field. Interceptors can be applied to one or more controllers.