added lang support to all html templates and cleaned up template rendering

common.go

@@ -3,7 +3,9 @@ package main
 import (
 	"crypto/rand"
 	"encoding/base64"
+	"encoding/json"
 	"html/template"
+	"net/http"
 	"strings"
 )
 
@@ -15,9 +17,35 @@ var (
 		"add": func(a, b int) int {
 			return a + b
 		},
+		"translate": Translate,
+		"toJSON": func(v interface{}) (string, error) {
+			jsonBytes, err := json.Marshal(v)
+			if err != nil {
+				return "", err
+			}
+			return string(jsonBytes), nil
+		},
 	}
 )
 
+// Helper function to render templates without elapsed time measurement
+func renderTemplate(w http.ResponseWriter, tmplName string, data map[string]interface{}) {
+	// Parse the template with common functions (including translate)
+	tmpl, err := template.New(tmplName).Funcs(funcs).ParseFiles("templates/" + tmplName)
+	if err != nil {
+		printErr("Error parsing template: %v", err)
+		http.Error(w, Translate("internal_server_error"), http.StatusInternalServerError)
+		return
+	}
+
+	// Execute the template
+	err = tmpl.Execute(w, data)
+	if err != nil {
+		printErr("Error executing template: %v", err)
+		http.Error(w, Translate("internal_server_error"), http.StatusInternalServerError)
+	}
+}
+
 func generateStrongRandomString(length int) string {
 	bytes := make([]byte, length)
 	_, err := rand.Read(bytes)