ch3.4

cmd/web/handlers.go

@@ -9,7 +9,7 @@ import (
 
 func (app *application) home(w http.ResponseWriter, r *http.Request) {
 	if r.URL.Path != "/" {
-		http.NotFound(w, r)
+		app.notFound(w)
 		return
 	}
 	files := []string{
@@ -19,21 +19,19 @@ func (app *application) home(w http.ResponseWriter, r *http.Request) {
 	}
 	ts, err := template.ParseFiles(files...)
 	if err != nil {
-		app.errorLog.Print(err.Error())
+		app.serverError(w, err)
-		http.Error(w, "Internal Server Error", http.StatusInternalServerError)
 		return
 	}
 	err = ts.ExecuteTemplate(w, "base", nil)
 	if err != nil {
-		app.errorLog.Print(err.Error())
+		app.serverError(w, err)
-		http.Error(w, "Internal Server Error", http.StatusInternalServerError)
 	}
 }
 
 func (app *application) snippetView(w http.ResponseWriter, r *http.Request) {
 	id, err := strconv.Atoi(r.URL.Query().Get("id"))
 	if err != nil || id < 1 {
-		http.NotFound(w, r)
+		app.notFound(w)
 		return
 	}
 	fmt.Fprintf(w, "Display a specific snippet with ID %d...", id)
@@ -42,7 +40,7 @@ func (app *application) snippetView(w http.ResponseWriter, r *http.Request) {
 func (app *application) snippetCreate(w http.ResponseWriter, r *http.Request) {
 	if r.Method != http.MethodPost {
 		w.Header().Set("Allow", http.MethodPost)
-		http.Error(w, "Method Not Allowed", http.StatusMethodNotAllowed)
+		app.clientError(w, http.StatusMethodNotAllowed)
 		return
 	}
 	w.Write([]byte("Create a new snippet"))

cmd/web/helpers.go

@@ -0,0 +1,22 @@
+package main
+
+import (
+	"fmt"
+	"net/http"
+	"runtime/debug"
+)
+
+func (app *application) serverError(w http.ResponseWriter, err error) {
+	trace := fmt.Sprintf("%s\n%s", err.Error(), debug.Stack())
+	app.errorLog.Output(2, trace)
+
+	http.Error(w, http.StatusText(http.StatusInternalServerError), http.StatusInternalServerError)
+}
+
+func (app *application) clientError(w http.ResponseWriter, status int) {
+	http.Error(w, http.StatusText(status), status)
+}
+
+func (app *application) notFound(w http.ResponseWriter) {
+	app.clientError(w, http.StatusNotFound)
+}