Step-5 Refactor

- Move all templating code to its own function.
- Handle non-existent pages in `viewHandler`.

Author: DehuaZhao

gowiki.go

@@ -26,11 +26,19 @@ func loadPage(title string) (*Page, error) {
 	return &Page{Title: title, Body: body}, nil
 }
 
+func renderTemplate(w http.ResponseWriter, tmpl string, p *Page) {
+	t, _ := template.ParseFiles(tmpl + ".html")
+	t.Execute(w, p)
+}
+
 func viewHandler(w http.ResponseWriter, r *http.Request) {
 	title := r.URL.Path[len("/view/"):]
-	p, _ := loadPage(title)
-	t, _ := template.ParseFiles("view.html")
-	t.Execute(w, p)
+	p, err := loadPage(title)
+	if err != nil {
+		http.Redirect(w, r, "/edit/"+title, http.StatusFound)
+		return
+	}
+	renderTemplate(w, "view", p)
 }
 
 func editHandler(w http.ResponseWriter, r *http.Request) {
@@ -39,8 +47,7 @@ func editHandler(w http.ResponseWriter, r *http.Request) {
 	if err != nil {
 		p = &Page{Title: title}
 	}
-	t, _ := template.ParseFiles("edit.html")
-	t.Execute(w, p)
+	renderTemplate(w, "edit", p)
 }
 
 func main() {