Receive value from handler in middleware

[oSethoum]

I wanna send the response value from the handler to the middleware, note that the middleware executes the next handler first, my little try looks like this. I tried setting value in the context but failed it comes back nil.

func Notify(next http.Handler) http.Handler {
	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		next.ServeHTTP(w, r)
                // get the response from the next handler somehow.

		// async notifying, doesn't slow the response
		go func() {
			for _, c := range writers {
                                // send response through this channel so the sse can notify the listenners.
				c <- r.URL.String()
			}
		}()
	})
}

[VojtechVitek]

Try this:
https://pkg.go.dev/github.com/go-chi/chi/middleware#NewWrapResponseWriter

func Notify(next http.Handler) http.Handler {
	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		var buf bytes.Buffer
		ww := middleware.NewWrapResponseWriter(w, r.ProtoMajor)
		ww.Tee(&buf)

		next.ServeHTTP(ww, r)

		fmt.Println(buf.String())
	}
}