footer: Add a semi-flexible template system

pkg/httpx/html.go

@@ -3,14 +3,23 @@ package httpx
 import (
 	"html/template"
 	"net/http"
+
+	"github.com/rs/zerolog"
 )
 
 // WriteHTML writes a html response of type T to w.
 // If an error occured, writes an error response instead.
-func WriteHTML[T any](result T, err error, template *template.Template, templateName string, w http.ResponseWriter, r *http.Request) {
+func WriteHTML[T any](result T, err error, template *template.Template, templateName string, w http.ResponseWriter, r *http.Request) (e error) {
+	// log any error that occurs;
+	defer func() {
+		if e != nil {
+			zerolog.Ctx(r.Context()).Err(e).Str("path", r.URL.String()).Msg("error rendering template")
+		}
+	}()
+
 	// intercept any errors
 	if HTMLInterceptor.Intercept(w, r, err) {
-		return
+		return nil
 	}
 
 	// write out the response as html
@@ -23,9 +32,9 @@ func WriteHTML[T any](result T, err error, template *template.Template, template
 
 	// and return the template
 	if templateName != "" {
-		template.ExecuteTemplate(minifier, templateName, result)
+		return template.ExecuteTemplate(minifier, templateName, result)
 	} else {
-		template.Execute(minifier, result)
+		return template.Execute(minifier, result)
 	}
 }
 

pkg/httpx/html_minify.go

@@ -1,3 +1,5 @@
+//go:build nominify
+
 package httpx
 
 import (

pkg/httpx/html_minify_off.go

@@ -0,0 +1,27 @@
+//go:build !nominify
+
+package httpx
+
+import "io"
+
+// MinifyHTMLWriter wraps the given io.Writer to minify the given html instead.
+// The writer must be closed explicitly.
+//
+// Specific environments may chose to disable http minification, in which case MinifyHTMLWriter becomes the identity function.
+func MinifyHTMLWriter(dest io.Writer) io.WriteCloser {
+	return noop{Writer: dest}
+}
+
+type noop struct {
+	io.Writer
+}
+
+func (noop) Close() error {
+	return nil
+}
+
+// MinifyHTML minifies the html source.
+// If an error occurs, returns the unmodified source instead.
+func MinifyHTML(source []byte) []byte {
+	return source
+}