feat(templates): Fallback image

services/templater.go

@@ -7,6 +7,7 @@ import (
 	"html/template"
 	"image/png"
 
+	"git.odit.services/lfk/document-server/templates"
 	"github.com/boombuler/barcode"
 	"github.com/boombuler/barcode/code128"
 	"github.com/boombuler/barcode/ean"
@@ -79,10 +80,14 @@ func (t *DefaultTemplater) GenerateBarcode(code string, format string, prefix st
 	return base64.StdEncoding.EncodeToString(buf.Bytes()), nil
 }
 
+func (t *DefaultTemplater) SelectSponsorImage(id int) (string, error) {
+	return templates.GetImage("error"), nil
+}
+
 func (t *DefaultTemplater) StringToTemplate(templateString string) (*template.Template, error) {
 	return template.New("template").Funcs(template.FuncMap{
 		"barcode":     t.GenerateBarcode,
-		"sponsorLogo": func(id int) string { return "a" },
+		"sponsorLogo": t.SelectSponsorImage,
 	}).Parse(templateString)
 }