Redirect for subrouters

[shamilovstas]

Commented here, but since the issue cannot be reopened, I opened this issue to continue the discussion.

Copy of my comment there:

I'm not sure whether my question relates to the initial question, but perhaps it makes sense when subrouters are used? Consider this:

router.Route("/{username}", func(r chi.Router) {
	r.Get("/", func(w http.ResponseWriter, request *http.Request) {
		// r.Redirect("/details")  <---- This is where I want to redirect to, keeping the subrouter's prefix (/{username}).
	})

	r.Get("/details", func(writer http.ResponseWriter, request *http.Request) {
		// ...                     <---- Redirects here
	})
} 

Originally posted by @shamilovstas in #709

[shivakumar2006]

I believe this is expected behavior in chi
Subrouters don't keep tracks of fully matched URL prefix, so the redirect can't goes to "/{username}", recommended approach is using URL Params, for example:

username := chi.URLParam(r, "username")
http.Redirect(w, r, "/"+username+"/details", http.StatusFound)

If this make sense, i'd happy to submit a small documentation update with an example to clarify this pattern