From 7d18008d808dd08927b37d8dbadb0e5621794156 Mon Sep 17 00:00:00 2001
From: Valentin Brandl <mail@vbrandl.net>
Date: Sun, 20 Apr 2025 00:27:16 +0200
Subject: [PATCH] Helper to render template

---
 handlers/index.go     | 16 ++++------------
 handlers/not_found.go | 17 +++++------------
 handlers/template.go  | 25 +++++++++++++++++++++++++
 3 files changed, 34 insertions(+), 24 deletions(-)

diff --git a/handlers/index.go b/handlers/index.go
index 42d78dd..a5ff491 100644
--- a/handlers/index.go
+++ b/handlers/index.go
@@ -7,16 +7,8 @@ import (
 )
 
 func (app *Application) Index(w http.ResponseWriter, r *http.Request) {
-	l := hlog.FromRequest(r)
-	l.Info().Msg("Index")
-
-	reqId := RequestID(r)
-
-	err := indexTemplate.Execute(w, templateData{
-		RequestID: reqId,
-	})
-	if err != nil {
-		l.Error().Err(err).Msg("error executing template")
-		http.Error(w, "Internal Server Error", http.StatusInternalServerError)
-	}
+	renderTemplate(*indexTemplate, nil, func(w http.ResponseWriter, r *http.Request) {
+		l := hlog.FromRequest(r)
+		l.Info().Msg("Index")
+	})(w, r)
 }
diff --git a/handlers/not_found.go b/handlers/not_found.go
index 7f949d6..00136ff 100644
--- a/handlers/not_found.go
+++ b/handlers/not_found.go
@@ -7,17 +7,10 @@ import (
 )
 
 func (app *Application) NotFound(w http.ResponseWriter, r *http.Request) {
-	l := hlog.FromRequest(r)
-	l.Info().Msg("Not found")
+	renderTemplate(*notFoundTemplate, nil, func(w http.ResponseWriter, r *http.Request) {
+		l := hlog.FromRequest(r)
+		l.Info().Msg("Not found")
 
-	reqId := RequestID(r)
-	w.WriteHeader(http.StatusNotFound)
-
-	err := notFoundTemplate.Execute(w, templateData{
-		RequestID: reqId,
-	})
-	if err != nil {
-		l.Error().Err(err).Msg("error executing template")
-		http.Error(w, "Internal Server Error", http.StatusInternalServerError)
-	}
+		w.WriteHeader(http.StatusNotFound)
+	})(w, r)
 }
diff --git a/handlers/template.go b/handlers/template.go
index 41e3f9b..f759332 100644
--- a/handlers/template.go
+++ b/handlers/template.go
@@ -2,8 +2,10 @@ package handlers
 
 import (
 	"html/template"
+	"net/http"
 
 	"git.vbrandl.net/vbrandl/go-web-template/assets"
+	"github.com/rs/zerolog/hlog"
 )
 
 var indexTemplate *template.Template
@@ -28,3 +30,26 @@ func (app *Application) ParseTemplates() error {
 
 	return nil
 }
+
+func renderTemplate(template template.Template, data map[any]any, additionalHandling http.HandlerFunc) http.HandlerFunc {
+	return func(w http.ResponseWriter, r *http.Request) {
+		l := hlog.FromRequest(r)
+
+		if data == nil {
+			data = make(map[any]any)
+		}
+
+		reqId := RequestID(r)
+		data["RequestID"] = reqId
+
+		if additionalHandling != nil {
+			additionalHandling(w, r)
+		}
+
+		err := template.Execute(w, data)
+		if err != nil {
+			l.Error().Err(err).Msg("error rendering template")
+			http.Error(w, "Internal Server Error", http.StatusInternalServerError)
+		}
+	}
+}