add ErrorPage PipeHandler

TODO

@@ -5,5 +5,6 @@
 * context use ResponseWriter instead of http.ResponseWriter OK
 * panic if write header after body                          OK
 * add Session                                               OK
-* add PipeHandler ErrorPage
+* add PipeHandler ErrorPage                                 OK
+* test and benchmark
 * Example

context_render.go

@@ -32,13 +32,8 @@ func (ctx *Context) NotModified() {
 	ctx.WriteHeader(304)
 }
 
-func (ctx *Context) NotFound(message string) {
+func (ctx *Context) NotFound() {
 	ctx.WriteHeader(404)
-	_, err := ctx.Write([]byte(message))
-	if err != nil {
-		ctx.Logger.Errorf(err.Error())
-		return
-	}
 }
 
 func (ctx *Context) Unauthorized() {

pipe_error_page.go

@@ -0,0 +1,19 @@
+package xingyun
+
+import "net/http"
+
+func (s *Server) GetErrorPagePipeHandler() PipeHandler {
+	return PipeHandlerFunc(func(w http.ResponseWriter, r *http.Request, next http.HandlerFunc) {
+		s.Logger.Tracef("enter error page handler")
+		defer s.Logger.Tracef("exit error page handler")
+
+		next(w, r)
+		ctx := GetContext(r)
+		status := ctx.ResponseWriter.Status()
+		if status >= 400 && status <= 599 {
+			if s.ErrorPageHandler != nil {
+				s.ErrorPageHandler.ServeContext(ctx)
+			}
+		}
+	})
+}

server.go

@@ -39,6 +39,7 @@ func NewServer(config *Config) *Server {
 	server.PanicHandler = DefaultPanicHandler
 	server.pipes = map[string]*Pipe{}
 	server.DefaultPipeHandlers = []PipeHandler{
+		server.GetErrorPagePipeHandler(),
 		server.GetLogPipeHandler(),
 		server.GetRecoverPipeHandler(),
 		server.GetStaticPipeHandler(),