From e7c7ec55acd7a0844288dab45def57be63d0d81d Mon Sep 17 00:00:00 2001
From: Scott Thompson <vbassassin@gmail.com>
Date: Mon, 18 Aug 2014 00:45:43 +0100
Subject: [PATCH] Added a NotFound() method so a handler can be specified in
 the event that no routes match allowing a custom 404 page to be produced

---
 README.md |  4 ++++
 routes.go | 15 ++++++++++++++-
 2 files changed, 18 insertions(+), 1 deletion(-)

diff --git a/README.md b/README.md
index 1e88ad0..db47c2f 100644
--- a/README.md
+++ b/README.md
@@ -46,6 +46,10 @@ You can specify custom regular expressions for routes:
 
     mux.Get("/files/:param(.+)", handler)
 
+You can specify a custom 404 not found route:
+
+    mux.NotFound(handler)
+
 You can also create routes for static files:
 
     pwd, _ := os.Getwd()
diff --git a/routes.go b/routes.go
index 6870373..92d8d39 100644
--- a/routes.go
+++ b/routes.go
@@ -38,15 +38,22 @@ type route struct {
 	handler http.HandlerFunc
 }
 
+type notFoundHandler func(http.ResponseWriter, *http.Request)
+
 type RouteMux struct {
 	routes  []*route
 	filters []http.HandlerFunc
+	notFoundHandler notFoundHandler
 }
 
 func New() *RouteMux {
 	return &RouteMux{}
 }
 
+func (m *RouteMux) NotFound(handler notFoundHandler) {
+	m.notFoundHandler = handler
+}
+
 // Get adds a new Route for GET requests.
 func (m *RouteMux) Get(pattern string, handler http.HandlerFunc) {
 	m.AddRoute(GET, pattern, handler)
@@ -206,7 +213,13 @@ func (m *RouteMux) ServeHTTP(rw http.ResponseWriter, r *http.Request) {
 
 	//if no matches to url, throw a not found exception
 	if w.started == false {
-		http.NotFound(w, r)
+
+		if (m.notFoundHandler != nil) {
+			m.notFoundHandler(w, r)
+		} else {
+			http.NotFound(w, r)
+		}
+
 	}
 }