refactor(templates): Dynamic image loading

services/templater.go

@@ -90,7 +90,11 @@ func (t *DefaultTemplater) SelectSponsorImage(id int) (string, error) {
 	return GetImage(sponsors[id%len(sponsors)]), nil
 }
 
-func FormatUnit(unit string, locale string, amount int) (string, error) {
+func (t *DefaultTemplater) LoadImage(name string) (string, error) {
+	return GetImage(name), nil
+}
+
+func (t *DefaultTemplater) FormatUnit(unit string, locale string, amount int) (string, error) {
 	var formatted string
 	switch unit {
 	case "kilometer":
@@ -111,7 +115,8 @@ func (t *DefaultTemplater) StringToTemplate(templateString string) (*template.Te
 	return template.New("template").Funcs(template.FuncMap{
 		"barcode":     t.GenerateBarcode,
 		"sponsorLogo": t.SelectSponsorImage,
-		"formatUnit":  FormatUnit,
+		"formatUnit":  t.FormatUnit,
+		"loadImage":   t.LoadImage,
 	}).Parse(templateString)
 }